Random thoughts of an astro major

Dark Matter Detected?

2008-04-21T23:42:00.003-04:00

Due a lack of exciting confirmed astronomy news lately, here is a piece discussing the potential detection of the dark matter candidates, WIMPS (Weakly Interacting Massive Particles).

A team in Italy, working on the DAMA/LIBRA experiment claims they have detected WIMPS, which may be anything from neutrinos to unknown particles. They attempt to detect a change in dark matter flux as the Earth travels around the sun, by looking for the recoil of electrons and nuclei in their detector due to the particles. They first have to remove detections, such as cosmic rays, due to other events, before they can analyze the data. As is pointed out in the aforementioned link, the found fluctuation is extremely small, and is not definitively due to dark matter at all.

Fix to "brain farts"?

2008-04-21T23:37:00.002-04:00

Researchers at the University of Bergen in Norway have found that the brains of volunteers have exhibited abnormal behavior up to 30 seconds before "brain farts". They hope that this knowledge will enable future devices to correct for potentially fatal human errors, such as those that lead to car accidents or industrial accidents. The only problem is that the research was done using a functional MRI, which requires one to be lying down in a tube to use.

Pennsylvania Primaries

2008-04-21T23:24:00.002-04:00

There are just over 7.5 hours until the polls open in Pennsylvania for the primary elections. Hillary came to Penn State yesterday, and only managed to draw a crowd of 1500 (Bill's crowd was 8000 when he came a few weeks ago, and Obama got 22,000). I was impressed with how well thought-out Hillary's plans seemed to be as she outlined them yesterday, and her most memorable quote was "When the cameras disappear and the lights are turned off, you're electing a president to solve problems, not give speeches".

There is no question Penn State students are for Obama, and Philadelphia will probably go Obama, but beyond that, this primary seems to be up in the air. I think Clinton's poll numbers are most likely inflated, due to the underestimated youth vote (many young people don't have landlines to answer polls), and even though the margin is at an estimated 5% in favor of Clinton, the race may be close to call.

lunar telescope

2008-04-16T23:42:00.002-04:00

Lunar telescopes have been proposed in the past. Naturally, the biggest obstacles are price, and how one could transport such a large device while requiring minimum setup time once at the moon. The Dark Ages Lunar Interferometer (DALI) would look far back into the universe using radio waves, to the cosmic dark ages, before the existence of stars. The only data that may be recorded from this time are the spin-flips of hydrogen atoms. Such measurements are not possible from Earth due to interference from man-made radio signals, but would be possible with this hypothetical interferometer on the far side of the moon.

moon plants?

2008-04-16T23:33:00.002-04:00

An ESA team has announced that they have come closer to terraforming the moon. The team planted marigolds in anorthosite, a mineral commonly found on the moon's surface, discovering that the plants did not need plant food to survive. With pure anorthosite, the plants did not grow, but upon the introduction of bacteria, they thrived.

This seems to be a step in the right direction in preparation for the day when a doomsday asteroid does actually strike Earth. Earlier today there were false reports that the Apophis asteroid, set to approach Earth in 2036, had 1 in 450 odds of impacting the planet. The odds are actually 1 in 45,000 (the reports claimed NASA's initial calculations were wrong, and were corrected by a 13 year-old German boy).

animals in space

2008-04-13T20:47:00.003-04:00

Friday Russia commemorated the first dog in space, Laika, who traveled into space 50 years ago, on November 3rd, 1957. She did not survive the endeavor; several hours into the flight she died from stress and overheating, most likely due to a failure in the thermal control system (temperatures reached 104 F). Even if she had survived the heat, the Soviets did not plan for reentry of the spacecraft; she was supposed to be euthanized by poisoned food.

Many animals who went to space died in orbit or shortly after returning to Earth, although some did survive, including a dog Strelka, whose pup was a gift from Khruschev to Caroline Kennedy. A Wikipedia article on all animals who have gone to space is here.

smallest extrasolar planet found

2008-04-09T20:24:00.002-04:00

A team from Spain's Superior Council for Scientific Investigations, led by Ignasi Ribas, announced today that they have discovered the smallest known extrasolar planet. The planet, GJ 436c, has a radius 150% of the size of the Earth, and weights five times as much as the Earth. At 5 solar masses, it is a rocky planet.

The planet orbits a red dwarf star 30 light years away in Leo. Like the discovery of Neptune, this planet was found by looking at gravitational perturbations of a nearby planet in the same solar system. Unfortunately the planet is outside of the habitable zone, with years merely 5 Earth days in length. However, this technique of planet finding promises to find Earth-sized planets soon, and perhaps even those in a more habitable range.

solar system similarity

2008-04-06T21:27:00.002-04:00

A solar system just discovered around another star, OGLE-2006-BLG-109L, looks suspiciously like our own. OGLE-2006-BLG-109L is about half the size of our sun. Two planets have been detected around it, and have radii, semi-major axes (distance to the star), and masses similar to those of Jupiter and Saturn. The planets were detected using gravitational microlensing by a team headed by Mark Dominick at St. Andrew's University in the U.K. In gravitational microlensing, the gravity of the planets and the host star act as a lens for a background star, magnifying the background star. Via the changes in brightness of the background star, it is possible to infer the mass of the planets.

It is hoped that such microlensing events will be able to find Earth-sized planets soon. SIM PlanetQuest, set to launch in 2015, may provide such discoveries. Kepler also promises to find terrestrial planets via the transit method, and will be launched in February.

black hole the size of a city

2008-04-01T23:21:00.002-04:00

Astronomers at Goddard have discovered the smallest known black hole, at 3.8 times the mass of the sun, making it 15 miles across. The previous record was 6.3 solar masses. Shaposhnikov and Titarchuk estimated the mass using a new method, measuring the oscillation of gas around the black hole. The largest confirmed mass of a neutron star is 1.9 solar masses, meaning there is still a gap of 1.9 solar masses to fill between the upper limit of observed neutron star mass and the lower limit of observed black hole (although there is a 2.7 solar mass neutron star that may be an anomaly).

obamamania

2008-03-30T20:14:00.003-04:00

Obama came to Penn State today, and spoke in front of a crowd of 22,000. They had 5000 preferred tickets, of which I was lucky enough to secure two, meaning I could at least see his facial expressions when the people in front of me weren't in the way. His speech was full of hope in a manner to which the average person could relate. He put himself on the level of the crowd, talking about how he made $12,000 a year at one point, and how his father left his family when he was two. At the same time, he emphasized his credentials, particularly the fact that he has studied the constitution thoroughly in his law practice.

Obama gave few details about the specifics of his policies, instead giving a more motivational speech that got the crowd wanting change. The crowd was very enthusiastic and pro-Obama, even shouting "don't go", when he announced he was on his final point. If Obama wins the November election, I think that a large portion of the change in the country will be due to normal citizens. As Obama said, "ordinary people can do extraordinary things when they work together." Obama has the backing of a large percentage of this nation's youth, who are more than ready for change, and will work to mend the wounds of the U.S. He advocated giving college students $4000 a year, in return for community service in some form, like the peace corps, or working in a homeless shelter. Hopefully this service would continue after the mandatory length, or at least drastically change the lives of those who had received this money.

I tried recording his speech, but I apparently only got the first 17 minutes because the battery in my recorder died. Here it is though.

election madness

2008-03-28T01:56:00.002-04:00

Candidates and their representatives have begun to flock to Penn State. Bill Clinton spoke tonight, in front of a crowd of ~7000. After many waited for 2 hours in the rain to get inside, and then another hour once inside, Clinton started (making him one hour late). It felt like much of his speech was about what he had done when in the White House, and suggested that Hillary would continue his legacy.

In terms of environmental policy, Clinton certainly proposed steps toward a greener economy. The only portion which I questioned was his eagerness to move away from nuclear energy, an energy form which he put on the same level as coal and oil. He mentioned that moving toward greener energy would create "green collar workers", and stimulate the entire economy. Because people are needed to evaluate the energy efficiency of buildings here and implement greener energies, it would be very difficult to outsource these jobs to other countries.

Naturally, he discussed Iraq, and the need to move troops out immediately. His analogy for Iraq was a person having a next door neighbor whose house burned down. Naturally, a good neighbor would allow their neighbors to move in with them temporarily; most people would let them move in for at least a month, maybe even up to six. After five years, however, it is beyond time for them to move on. Tactically, this analogy never addressed the fact that the basis for our invasion of Iraq was unfounded, as no WMDs were found.

As for health care, he mentioned that Hillary's policy would be to take a certain fixed percentage out of the income of everyone who did not already have health insurance so that they would be covered. They could then opt to upgrade for extra coverage. Apparently 30% of the money we pay toward insurance today goes toward paperwork. Because of this, our health system at present is $700 billion more expensive than the systems of France, Germany, and Japan (known for good health care coverage).

Next up in the series of presidential candidates visiting Penn State is Obama, coming to campus this Sunday, followed by Ron Paul on the 11th. No word from McCain, but I can't imagine that it is strategically advantageous for him to come before the primaries on the 22nd. Perhaps he'll speak near the date of the November election, as Pennsylvania is traditionally a swing state.

XCOR releases rocket plans

2008-03-26T23:08:00.002-04:00

XCOR, a California-based company attempting to venture into privatized space travel, has released plans for a rocket plane. The Lynx vehicle at 8.5 m in length can hold one passenger and the pilot, and travel 60 km above the Earth's surface. XCOR hopes Lynx will be flying by 2010, taking off from the Mojave Air and Spaceport in California in an airplane-like manner. Lynx should cost considerably less than its main competitors Astrium and Virgin Galactic, in part due to its lower altitude capabilities.

$30 paternity test

2008-03-26T23:05:00.004-04:00

Rite Aid has begun selling a DNA paternity test kit for $30 by company Identigene. After a saliva sample is taken, the Identigene will analyze the kit for an additional $119. Results take 3-5 days, but are not admissible in court. The only question now seems to be, how does one go about asking for a saliva sample from the potential father?

most distant object visible to the naked eye

2008-03-21T17:16:00.003-04:00

Swift, a gamma ray satellite operated by Penn State, detected five Gamma Ray Bursts (GRBs) within 24 hours on Wednesday (an extremely high number). One of them was the most distant object ever seen by the naked eye, at 7.5 billion light years away (the galaxy M33 used to hold this record, at 2.5 million light years away). The burst was also the most intrinsically bright object ever recorded, at 2.5 million times the luminosity of the brightest supernova.

GRBs form when the core of a giant star collapses to form a neutron star or black hole, emitting jets of energetic particles. It is not known what made this burst in particular so bright; it may have been more energetic than normal bursts, or its jet may have just been aimed directly at Earth.

the race for a green car

2008-03-21T17:08:00.003-04:00

The X Prize foundation announced yesterday that they would be funding a prize for a car that can get 100 mpg. The prize comes with a $10 million reward, and hopes to decrease climate change. A race is set for 2009, in which teams will compete in preliminary and final long-distance races. The cars must be fuel efficienct, hit a minimum speed, and show that their car can be mass-produced.

There will be two classes of cars: mainstream, and alternative. Mainstream cars must seat four, have four wheels, climate control, an audio system, 10 feet of cargo space, and must be able to go from 0 to 60 in 12 seconds. They must hit a minimum top speed of 100 mph as well. Alternative cars must seat 2, can have any number of wheels, and must hit at least 80 mph.

worlds of methane and water

2008-03-21T16:58:00.002-04:00

A carbon-containing molecule has been discovered for the first time on an extrasolar planet. Methane was found on star HD 189733d, which is 63 light years away in Vulpeca. Water was detected in its atmosphere, but the planet is much to close to its host star to be habitable. Giovanna Tinetti, of University College London, along with collaborators Mark Swain and Gautam Vasisht of the Jet Propulsion laboratory made the discovery with Hubble. They hope to find more signatures of organic compounds in the future, a step toward finding extraterrestrial life.

Titan, Saturn's moon, may have an ocean of water, according to data from Cassini. Radar images show that beneath its thick icy crust may be a deep sea of liquid water. Titan is already known to have organic material, meaning there is some chance of finding microorganisms on the moon, despite incredibly cold temperatures.

astronomy+women=?

2008-03-18T22:16:00.002-04:00

Steinn recently linked to a blog meme that asked people to name 5 women in their field of science not at their university. While I find this easy to do in astronomy, even as an undergraduate, it does bring up a good point in that women are less recognized in scientific fields.

Take Penn State's Collegian article on Monday about the department. Even my mom, who is about as far from being a feminist as is possible for a female, pointed out that none of the featured astronomers were women. Also of note is that the article is written by a female.

EU set to further cut greenhouse gases

2008-03-14T01:49:00.002-04:00

EU leaders, at their spring summit in Brussels, are set to further decrease greenhouse emission standards. The Slovenian Prime Minister, Janez Jansa, predicts that they will set goals of a 20% emission reduction by 2020.

Energy standards seem to be very political in the EU, as I have found out in Bulgaria so far. In order for Bulgaria to join the EU, they had to shut down all but two of their nuclear reactors, which made Bulgarians rely on less-green forms of energy. They do plan on restarting some of their nuclear reactors now that they have entered the EU, but it seems unreasonable that they had to do so in the first place.

One of our speakers yesterday who is a government consultant on greenhouse gases pointed out that Bulgaria has managed to cut their emissions by 49% since 1988. He failed to point out that a large percentage of this cut (15% or so) is due to a reduction in population since 1988. I don't know if they would still be meeting Kyoto standards if emission standards were set per capita. Apparently if you meet Kyoto standards, you can sell any of your leftover emissions to other nations. In theory this means that poor nations will benefit from the sale of emissions to more industrialized countries, but it seems as if this partially defeats the purpose of the protocol.

Mars water ice under surface

2008-03-14T01:42:00.002-04:00

The Mars Reconnaissance Orbiter has very likely detected a large amount of water ice below the surface of the planet. The water ice has been detected at mid-northern latitudes, unlike the previous detections at the poles. Detected by Shallow Radar (Sharad), the water ice was found by sending radio pulses through the surface and measuring the time delay as the pulses bounce back.

education in Bulgaria

2008-03-12T01:50:00.002-04:00

On Tuesday I visited two elementary schools as well as a finance high school in Sofia. The educational system here seems to be very good; the teachers are extremely enthusiastic, and the curriculum seems to be challenging. Students begin learning English in 1st grade here, and then pick up a second language in 5th grade. Our translator during the tour was a 4th grader who had only had English in school, but spoke perfectly. Apparently Bulgaria constantly outperforms the rest of Europe in math, as well. It seems as if they don't get nearly the credit they deserve in terms of education, mostly because financial resources are lacking.

The financial high school sounded very prestigious, and was even recognized by a U.S. senator for its achievements. Most students did an exchange program for at least a short period; they also had a semester-long exchange with a financial school in South Korea. Upon graduation, 100% of students entered a university.

Cassini to Study Saturn Moon Plumes

2008-03-12T01:44:00.002-04:00

Today Cassini will pass within 30 miles of Enceladus's surface in order to further study the geysers and learn how they form. In 2005 plumes were observed erupting at Enceladus's south pole with ice particles and water vapor. Cassini's flyby will determine the chemical makeup, as well as size, speed, and density of the various particles. It also will determine whether or not the geysers contain ammonia, which could be indicative of liquid water under the saturnian moon's surface.

21st century commandments

2008-03-10T15:51:00.002-04:00

The Vatican has announced some 21st century commandments, including "thou shalt not pollute". It's a shame Bulgaria is mostly Eastern Orthodox and not bound by that commandment. We went on a tour of Sofia today, and the pollution is horrible. There is litter on every square meter of green space, and there is significant smog from inner city factories. I think that may be a legacy of communist policies; environmental issues were not the largest concern pre-1989.

Real life death star?

2008-03-10T15:29:00.002-04:00

Peter Tuthill from the University of Sydney and collegues have determined that star WR 104 may explode within a few hundred thousand years, and could cause the extinction of life on Earth. This star is locked into orbit with another star, and has produced a pinwheel-shaped inspiral of gas. A Wolf-Rayet star, WR 104 is an unstable star which, upon going supernova, may emit very high energy gamma rays toward Earth. It is a mere 8000 light years away, about 1/4 of the distance to the center of the Milky Way. While the gamma rays would not penetrate the Earth's atmosphere, they could damage the stratosphere and cause a mass extinction.

This seems to be another terrific candidate to add to the list of methods of mass extinction on Earth. The list so far:

1. A nearby supernova explosion
2. An asteroid impact (Apophis in 2036? 1 in 45,000 odds)
3. The sun turning into a red giant (5 billion years)
4. Milky Way merger with Andromeda (several billion years; not a likely extinction though, as the odds of stars colliding is very small)
5. Humans destroying the ozone layer through pollution
6. Nuclear Winter
7. Deathly biological epidemic
8. More creative ways?

It would be interesting to see a calculation of what the odds are for each mass extinction, at least those that don't involve human destruction.

Foldable Car

2008-03-07T22:08:00.003-05:00

Engineers at MIT have unveiled a model for a foldable car. Slightly smaller than the Smart Car, the car would be able to fold into a shape that would only take up an eighth of a regular parking space. They state that the car would be able to drive itself, and at the push of a button look for a parking spot next to cars similar to itself. The car would run on a rechargable battery, and could be hooked up to an electricity grid while parked

Large Binocular Telescope First Light In Both Eyes

2008-03-07T21:55:00.003-05:00

An image produced with both telescopes of the Large Binocular Telescope, a picture of spiral galaxy NGC 2770, was released yesterday. The first mirror had its first light in October of 2005, producing an image of Andromeda. Located on Mount Graham in Arizona, the LBT has two 8 meter mirrors, and has a resolution ten times better than that of Hubble. Its light gathering power is the same as an 11.8 m telescope, and resolution is the same as a 22.8 meter telescope. The telescope has an ability to see in ultraviolet, visible, and infrared light, making it possible to create composite images.

mind-reading?

2008-03-05T23:45:00.003-05:00

Researchers at UC Berkeley have found a way to read people's minds with fair accuracy, without any sort of ESP. They used functional MRIs to scan the brain, and measure blood flow patterns in the visual cortex of two research team members as they looked at 1,750 different images. They then showed them 120 new pictures, and from previous data, the computers were able to predict the images the volunteers were looking at with 92% and 72% accuracy.

This could certainly have new implications for interrogation techniques.

pseudoscience and Hitler

2008-03-03T23:08:00.002-05:00

Apparently the U.K. hired an astrologer during WWII to write horoscopes for Hitler and the Nazi leaders. Thankfully, the military leaders found the astrologer, Louis de Wohl embarrassing, although he was temporarily promoted to British army captain. Winston Churchill, who did not believe in astrology, sent de Wohl to the U.S. to try to convince Roosevelt that Hitler would fall within months if the U.S. entered the war.

In astronomy, there is a constant battle to fight confusion with astrology. I can't count the number of times I've been asked about reading horoscopes, or what the alignment of the planets means. One of my fellow astronomy majors actually believes in astrology, and attempted to give several planetarium shows where she incorporated her astrological views. Hopefully she won't be going to graduate school where she can perpetuate these myths further, but she has grades good enough to do so.

avalanche on Mars

2008-03-03T23:05:00.002-05:00

The Mars Reconnaissance Orbiter caught a picture of an avalanche at the Martian north pole. The picture was accidentally caught, as the MRO was attempting to track seasonal changes at the Martian poles. The poles of Mars, made of frozen carbon dioxide, are good candidates for the discovery of liquid water. It is thought that beneath these CO2 ice caps liquid water may exist.

Fear of Snakes Hardwired

2008-02-29T22:49:00.002-05:00

According to a group lead by DeLoache and LoBlue at the University of Virginia, a fear of snakes is hardwired in humans. They tested a group of adults and a group of three year-olds, and asked them both to pick out a snake amongst a group of 8 other non-venomous creatures, and asked them to pick out a non-venomous creature amongst a group of 8 snakes. Both groups showed equal time in picking out the snakes, but picked out the non-venomous creature in a slower time. They believe the fear is innate, because snakes presented a threat to pre-humans.

U.K. back on Gemini project

2008-02-29T22:46:00.002-05:00

Britain recently announced that it would stay in the Gemini program, and would make up for a lack of funds by selling some of the telescope time. Good news for U.K. astronomy, which seemed to be headed downhill after a funding cut in November.

When to talk to children about AIDS

2008-02-26T16:59:00.002-05:00

The New York Times discusses a documentary of 4 and 6 year-old Sevilla and Vineeta Henessey reporting on the 2006 International AIDS Conference in Toronto. They ask experts in the field about what AIDS is, how it is transmitted, and how they can make it stop. Their parents, the producers of the documentary, think that there is no age too early to start talking about the subject, and claim that it is only adults who make such things taboo. The documentary can be viewed or downloaded legally for free at the above link, or ordered for $6 on DVD. The girls do an outstanding of interviewing all sorts of people at the conference, from medical experts to sex workers, and it is a video I would highly recommend.

Politics on the brain

2008-02-26T14:02:00.003-05:00

Politics is beneficial for neurological health, according to neuro-pharmacologist John D. Roache of the University of Texas Health Center at San Antonio. Previous studies have shown that an active person, one who partakes in activities such as crosswords or exercise, may decrease their risk of dementia. Being emotionally involved in politics seems to produce similar results, regardless of political alignment.

Asteroid intercept design competition

2008-02-26T13:41:00.016-05:00

SpaceWorks Engineering has won a $50,000 competition to design a mission to rendezvous with the asteroid Apophis. The asteroid will pass nearby Earth in 2029, and has a 1 in 45,000 chance of impacting Earth in 2036. The mission will collect data from the satellite, and hopefully constrain its orbital parameters at the original pass near Earth, to determine whether or not there needs to be a follow-up mission to destroy the satellite.

Although Russia and China have vocally disapproved of the U.S.'s destruction of the spy satellite that was going to crash into Earth, this technology could be a vital step in figuring out how to destroy a doomsday asteroid. If the asteroid were to hit, it would have an impact of 880 Megatons of TNT, over four times the 1883 eruption of Krakatoa. Depending on where it hit it could have a variety of results; if it hit Venezula/Columbia, it could kill 10 million, whereas if it hit several thousand miles off of the west coast of the U.S. it would certainly produce devastating tsunamis.

fastest way to walk up a hill

2008-02-23T23:53:00.002-05:00

The fastest way to walk up a hill turns out to be zigzagging, according to research by Marcos Llobera and T.J. Sluckin of the University of Southampton. At some point, it is metabolically inefficient to go straight uphill, and zigzagging prevails. The article didn't mention the slope at which this concept becomes effective, nor the type of zigzag one should walk in. Instance #50321234234 where physics doesn't actually work in everyday life. Thanks biology.

dark matter stars

2008-02-19T18:50:00.002-05:00

A team led by Katherine Freese of the University of Michigan suggests that the earliest stars in the universe may have been powered by dark matter. Dark matter makes up 3/4 of the mass of the universe today, and would have made up a larger fraction in the early universe. Weakly Interacting Massive Particles (WIMPS), one of two leading dark matter candidates, could have collided and annihilated at such a rate in the early universe that a protostar could have maintained gravitational stability. Freese hopes that data from JWST will be able to see back to the time at which dark matter stars existed.

electricity-producing fabric?

2008-02-15T00:14:00.003-05:00

The latest announcement in a string of new methods to produce energy is a microfiber fabric that makes its own electricity. The research, led by Zhong Lin Wang at Georgia Tech, takes advantage of zinc oxide nanowires that can be imbedded in fabric. As these wires brush against each other due to human motion, they will produce enough electricity to recharge a cell phone or run a small MP3 player. Unfortunately zinc oxide degrades when wet, so the team is now researching methods to coat the fiber to protect it as it goes through the laundry.

two planets found using microlensing

2008-02-14T23:58:00.003-05:00

Two planets were found orbiting star OGLE-2006-BLG-109L, with sizes and orbits similar to those Jupiter and Saturn, according to Reuters. This is the first time gravitational microlensing has been used to discover two planets orbiting the same star. Gravitational microlensing, an effect that warps spacetime as described by Einstein's theory of general relativity, causes light from the background star to be focused by foreground planets, thus magnifying the star. The research was led by Scott Gaudi of Ohio State, and involved a team of 80-some members as part of the Optical Gravitational Lensing Experiment.

Most known extrasolar planets have been found using the radial velocity method, which determines the gravitational perturbations of stars by their planets. This method, however, is biased toward finding planets close to the star (greater gravitational influence, as gravitational force is inversely proportional to the distance squared), making detection via microlensing vital to the study of where gas giant planets tend to lie in solar systems.

12.8 billion year-old galaxy found

2008-02-12T21:36:00.000-05:00

A team at UC Santa Cruz led by Rychard Bouwens has discovered a galaxy that formed a mere 700 million years after the Big Bang. The galaxy, A1689-zD1, was observed by Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS), and appears to be undergoing a period of intense starbirth. According to Garth Illingworth, a member of the research time, "this is the most detailed look to date at an object so far back in time." The galaxy is a billion times the mass of the sun, and only 2000 light-years across, significantly smaller than the Milky Way.

Science Debate date fixed

2008-02-12T21:19:00.000-05:00

Science Debate will officially be held at 7 p.m. on April 18th at the Franklin Institute in Philadelphia, four days before the Pennsylvania primary. They have invited the "viable" candidates-- McCain, Huckabee, Clinton, and Obama. The debate will be held even if only one candidate shows up; I am guessing the difficulty will be in getting the first candidate to agree.

more than meets the eye in German apartment fire

2008-02-10T21:04:00.000-05:00

Although there have been numerous reports about the apartment fire in Germany that took nine lives last Sunday, only recently have news sources reported potential arson due to racial tension.

I was suspicious when the news first came out, given that all of the people in the pictures appeared to be ethnically Turkish (a reaction most likely due to the fact that I took an entire course on Turkish-Germans). There are 2.7 million Turks in Germany, mostly relatives of guest workers who came over to West Germany as part of the economic wonder that took place in the 60s and 70s. Racial tension is high, as until recently, it has been virtually impossible for these guest workers and their children to receive German citizenship. Originally, it was not even possible for children of non-German decent to receive German citizenship if they were born in the country; now if their parents have resided in the country for 8 years they may become German citizens.

The Turkish Prime Minister Recep Tayyip Erdogan, visited the fire site, and called for Turkish-Germans to integrate into German society, but not to assimilate. German officials responded by saying that Erdogan's statements were counterproductive, and stressed that it was not ethnic tension that caused the fire. Racist graffiti was found in the building, but was thought to have existed long before the fire.

For anyone interested in Turkish-German issues, I recommend movies by Fatih Akin, like Gegen die Wand (English title Head On) and and Kurz and Schmerzlos (translates to Short and Painless, although I'm not sure of the actual English title).

office to be warmed by body heat

2008-02-10T20:59:00.000-05:00

According to BBC, the Jernhusen company of Sweden intends on using heat from subway passengers to warm an office building adjacent to Stockholm's central station. They hope it will provide 15% of the heat energy to the 40,000 square meter building by transforming heat from passengers into hot water, which will then be pumped into the heating system of the building.

produce your own electricity... by walking

2008-02-10T20:38:00.000-05:00

The Associated Press reports on a device that can produce electricity as a knee moves back and forth while a person is walking. Max Donelan, one of the developers of this new technology, from Simon Frazier University, likens it to the method by which hybrid electric cars produce electricity from braking.

A minute of walking can produce enough electricity to power a cell phone for 10 minutes. Other potential uses include powering a portable GPS, or a motorized prosthetic joint.

more evidence for water in the solar system

2008-02-07T00:17:00.000-05:00

It has been thought for some time that Enceladus, a moon of Saturn, has water. With a white shell of ice, Enceladus is 504 km across, with a surface only marred by a few grooves and craters. According to AFP, a team led by Juergen Schmidt of the University of Potsdam has discovered a plume of water being ejected from a "cryovolcano" on the moon's surface. The images, taken by the Cassini probe, suggest that tidal heating due to the gravitational pull of Saturn may be the cause of friction that causes the water to warm. At maximum temperatures of -193 C (-315 F) on the surface and -133 C (-207 F) in the cracks, however, the most evolved form of life that could evolve on this moon is thought to be microbial in nature.

tattooed vaccines?

2008-02-06T23:54:00.001-05:00

Along the lines of food being used to kill intestinal worms, BBC News reports on a German study that shows that tattooed vaccines are 16 times as effective as normal vaccines in mice. The rapidly vibrating tattoo needle is believed to be more effective in producing antibodies because it causes more damage. Because this method of administering vaccines would be more painful than conventional ways, it would not be used for preventative vaccinations.

A new cure to illness

2008-02-05T22:29:00.000-05:00

According to the NYT, Kraft foods has announced that they will start producing food meant to kill intestinal worms. While they are not sure what form the food will take, they will distribute it primarily in rural Asia, Africa, and Latin America.

car-free in a nation full of oil

2008-02-05T22:24:00.000-05:00

The Science Times reported today on Masdar City, a community to be located right next to Abu Dhabi's international airport. 2.3 square miles in size, the community will be car-free, and hidden behind walls to divert hot desert winds and airport noise. All of its energy will be produced from sunlight, and water will flow from a solar-powered seawater-desalinization plant. Greenhouses will be a source of produce, and all waste will be composted or recycled.

science debate 2008 gets even more publicity

2008-02-05T00:41:00.000-05:00

Not only did Science Debate 2008 receive the endorsement of the American Association for the Advancement of Science Friday, it received the endorsement of the National Academy of the Sciences today. Covered in a story by PBS, the debate has the backing of 21 Nobel laureates and over 12,000 others.

When I talked with the president of the American Astronomical Society, Dr. Craig Wheeler, while in Austin, he didn't see potential for a debate, but the motion for one has gotten significantly stronger over the past month. The email update I received said that they had a date and an extremely attractive location, and were going to be inviting the candidates later this week.

space race part 2-- giant telescopes?

2008-02-04T20:44:00.000-05:00

The AP reports on the next generation of ground-based telescopes set to be constructed in the next decade, from the Giant Magellan Telescope, to the Thirty Meter Telescope, to the European Extremely Large Observatory. The Giant Magellan Telescope is set to go in at Las Campanas, Chile, but the other two haven't selected sights yet. The improvement in image quality has been compared to switching from regular TV to HD, with mirrors ranging from 80-138 feet.

some science shatters human dignity

2008-02-03T03:54:00.000-05:00

The pope has condemned some forms of science which "shatter human indignity". Topics such as embryonic stem-cell research and artificial insemination fell into this category. He warned against the "seductive" powers of science, but assures that the Catholic church does not intend to hinder scientific progress.

Rogue Stars in Milky Way Center

2008-01-30T18:11:00.000-05:00

A group of 10 rogue stars has been found by members of a team at the Carnegie Institution to be speeding away from the center of the Milky Way, at velocities exceeding the gravitational escape velocity, making them so called "high velocity stars". Nine out of the ten stars are thought to have originated near the Milky Way's supermassive black hole, but the last star appears to be coming from the direction of the Large Magellanic Cloud. The mechanism for its acceleration is puzzling, given that there is no known supermassive black hole in the LMC.

Recent simulations by Sherwin et al. have suggested that one of these such hypervelocity stars may have ventured into the Milky Way from the Andromeda Galaxy.

grad school essay advice

2008-01-30T16:42:00.000-05:00

Female Science Professor has advice on what to write, or what not to write, in grad school admissions essays.

in memory

2008-01-29T00:29:00.000-05:00

Today is the 22nd anniversary of the Challenger tragedy.

Anthropocene Epoch?

2008-01-28T00:00:00.000-05:00

According to LiveScience, the impact of humans upon the Earth could be classified as the beginning of a new epoch; from the Holocene to the Anthropocene, a transition that occurred over the past 200 years. Altered erosion patterns, global warming, and acidification of the ocean are just several things that separate this new epoch from the last. Researchers on soil infertility have found enough evidence from soil alone to distinguish these time periods. These changes, according to prominent geologists such as Penn State's Richard Alley, will be clearly visible upon analysis by geologists hundreds or thousands of years in the future.

We had better put more money into figuring out how to terraform Mars if we continue at this rate. If we have managed to so negatively impact the planet in 200 years, one cannot help but wonder what this increasing devastation will do by the end of our lifetimes.

More UK cuts

2008-01-25T23:30:00.000-05:00

Big news earlier this year was that the UK withdrew its partnership from the Gemini Telescope. Now the European Synchrotron Radiation Facility may be the next partnership from which Britain withdraws. The facility, built in 1992 in Grenoble, France, has proven vital in determining the structure of materials using x-ray beams. According to BBC News, it needs an upgrade on the order of hundreds of millions of dollars to stay open, money it may not get given that Britain had a 14% financial share in it.

The financial woes of the facility are not aided by the fact that Germany is cautious to put money into an old project when it is in the midst of creating the X-ray Free Electron Laser.

Astro... or is it?

2008-01-24T14:58:00.000-05:00

The subject of astronomy suffers a significant number of misconceptions; from an association to astrology to confusing it with rocket science. Articles like this one, discussing a rock on Mars that "looks like a human" do not aid in the endeavor to set things straight. Although BBC does not endorse the fact that the image may contain an alien, the fact that it publicizes such a ridiculous idea takes steps backward in the mission to educate the layman about astronomy.

This article was not the only one of its type seen in the news recently. More UFO sightings were reported over Texas; it turns out, however, they were merely jets.

AAPT day 4

2008-01-23T19:34:00.000-05:00

The session I went to this morning was on women and minorities in physics. One of the most interesting statistics was that while 13% of African-Americans who enroll in college go to a historically black college or university, 60% of African-American physics majors graduate from one. This suggests something is very wrong with the approach of regular universities. The person giving the talk, from the American Institute of Physics, indicated that African-Americans show the same amount of interest in physics at the end of high school as Caucasians do, but somewhere in college they are driven away from the subject. He stated that many times African-Americans are told that physics is a "very difficult subject", and lack role models at universities.

Interestingly enough, I was discriminated based on age at the aforementioned session. First, they almost didn't give me a packet with a printout of the slides from the first speaker, once they looked and saw who I was. Then, they refused to let me ask a question at the end of the session, despite calling on people who had asked questions already. Apparently I couldn't possibly have an intelligent question to ask on the session topics, or really care about what is going on, despite having chosen to attend the talks myself (and having been one of the only ones to have taken meticulous notes).

After getting home, I got an email from the physics department saying they wanted to have a luncheon for female physics majors. This is the first time I've ever heard of them trying something like this, and wonder what motivated them to do so.

AAPT day 3

2008-01-23T00:59:00.001-05:00

Today's most interesting talk that I attended was given by a professor from the University of Washington, D.C. He created a program that targeted incoming freshman who scored the lowest on the math proficiency exam, and would have to take two remedial math classes before moving on to college level math. This past summer, there were 16 students in the 8-week program. They received $1000 and free room/board, and met for four hours per day. They had very rigid rules, were provided with all supplies needed, and had to complete the homework in the classroom. The course covered everything from multiplication tables through algebra. Out of those who took the class, 9/16 placed out of both remedial math courses, and only 2 had to take both courses. 5/16 enrolled in either the chemistry or physics major.

A related question is when is it too late to recruit students? Can students like those who took remedial math possibly make up for the years that they have fallen behind to make it as a physics major at an institution such as Penn State? At smaller schools, it may be easier; they get more attention, and often have less rigorous physics requirements. Even if a smaller institution is better at fostering their development, can they get true research experience at such an institution (not just calling classical mechanics experiments research, as seems to be the case in many instances)?

encouraging minorities in physics/astro

2008-01-21T22:26:00.000-05:00

The question of how to best perform outreach targeting minority groups has nagged me for a long time; yesterday's revelation that only 50 African American females have ever received a physics PhD in the United States caused the question to resurface. Penn State's astro and physics departments are severely lacking in minorities; out of all undergraduates in both departments, I know a total of one minority set to graduate in physics, and the racial diversity of the faculty is not significantly better.

The best method to recruit minority students and retain them in these majors is especially difficult to determine in the center of Pennsylvania, at least in terms of what the Society of Physics Students can do. With the exception of State College, the rest of central Pennsylvania is almost entirely white, making it extremely difficult to host programs purely for minorities in the area. The problem also lies in the fact that even if we were to host a program, it would be difficult to provide role-models for the school students, because there are so few minority students and faculty members at Penn State.

The educational community seems to be presently very focused on women in these fields, but does not seem to be doing enough to promote minority interest, as reflected by the fact that there seems to be double the number of sessions about evening the gender balance in physics at the meeting. I was hoping to be able to talk to people from Hampton University, a historically black university that brought multiple representatives to the conference, but I haven't seen them since the SPS poster session/jeopardy game last night. Apparently 20/25 students in the physics major there are female.

AAPT day 2

2008-01-21T22:10:00.000-05:00

Today was when the talks truly got started at the AAPT meeting. We decided that the meeting is more of an education with a physics slant than a physics meeting with an educational slant. While I think our physics education major has gotten a fair amount out of the meeting, those wanting to do outreach haven't found exactly what they have been looking for.

I haven't had any inspirational ideas yet, but hopefully in the next two days I'll come up with something. I plan on forcing everyone on the trip from our SPS chapter to sit down at some point and help me come up with outreach activities we can do this year, since this trip was entirely covered by SPS funds.

The largest revelations from today's talks were that 1. female-dominated high school lab groups tend to be the most efficient and have everyone participating (whereas the male-dominated groups procrastinate and generally have one person, often female, do the job); and 2. females do significantly worse in college physics than males when their prior physics backgrounds are considered. I wish more data existed for these sorts of studies; it is clear that a significant number of people presenting have not analyzed their data thoroughly enough to eliminate sources of bias and draw clear conclusions.

conferences part 2

2008-01-20T23:46:00.000-05:00

I just arrived in Baltimore for the American Association of Physics Teachers meeting. Eight undergrads from Penn State are here, as part of the Society of Physics Students. Tonight there was a short SPS poster session, followed by SPS jeopardy. In an hour I think I got almost as many visitors to my poster as the entire day at AAS.

Even though AAPT met concurrently with AAS in Seattle last year, I didn't attend any of the AAPT events, so this will be a new experience. I'm hoping to get new outreach ideas, and learn more about the statistics of the makeup of people in physics. I have already learned from physics jeopardy that there have been a total of 50 African American females graduate with physics PhDs. I don't know how much Penn State can do directly to change that, but I certainly would like to do something about it.

I was hoping to be able to continue getting press releases from AAS, but I haven't heard back from the press officer since inquiring. I had overheard him talking to a grad student freelance writer about being put on some email list with the releases, and thought that I might be able to continue to post on such events. I suppose I will have to rely on secondary news sources for any updates I have.

More Mercurian News

2008-01-18T19:09:00.000-05:00

The European Space Agency has just signed on to launch the probe BepiColombo in 2013, which will arrive at Mercury in 2019. ESA will produce a planetary orbiter that will, with its eleven instruments, image the surface of Mercury and collect data on the planet's composition. Japan is partners in this endeavor, and will be responsible for a magnetospheric orbiter, that will investigate the planet's magnetic field. Johannes Benkhoff, ESA project scientist on the mission, says that NASA's Messenger mission will only survey 1/4 of the planet's surface, but BepiColombo will be able to produce a fuller view of the planet, due to the probe's close orbit.

The mission will provide the most comprehensive and highest resolution of the planet's surface to date. It will also provide the first infrared images of the planet, which will enable scientists to determine surface composition and obtain temperature maps. Finally, it will determine with the great accuracy Mercury's gravitational field, useful in measurements of general relativistic effects.

Mysterious Mercurian Landscape Seen

2008-01-16T14:25:00.000-05:00

Just released Messenger pictures have revealed a face of Mercury that has never before been seen. It shows a good view of the 800-mile-wide Caloris Basin. More images will be revealed later today, although the most detailed Messenger images of Mercury will not be released until it orbits the planet in 2011 (it is only on a flyby now).

MP3s of AAS audio

2008-01-16T13:09:00.000-05:00

It appears the site I was using to post the AAS audio deletes the files after a few days, so I'll have to find an alternative method of posting files next time. In the meanwhile, I'll happily take requests for any of the audio I tried to post (name your format), or the text of the Craig Wheeler interview. There doesn't seem to be a point in reposting everything to have it shortly deleted.

Graduate School in Europe

2008-01-13T15:42:00.000-05:00

At a session on attending graduate school in Europe, representatives from schools in the United Kingdom, Switzerland, and Germany attempted to clarify the complexities of the application process to American students. The graduate schools in Europe are attempting to conform to the Bologna Plan, which involves converting to the Anglo-Saxon scheme of bachelor's, master's, and doctorate. Presently in these countries, students who have completed their undergraduate studies have completed the equivalent of the masters, and only need three years to complete their PhD.

The U.K. representatives discussed the problems of going to graduate school as an American student. Funding there does not exist for non-EU students, meaning American students must look for scholarships such as the Rhodes and Marshall scholarships. The average graduation time is 3 years and 8 months, and there are 125-150 PhDs granted per year. 20% of graduates find a permanent position within 10 years. One large difference in the United States is that it is nearly impossible to change projects once admitted. 90% of students complete their PhDs, and 1/3 of students are women.

The U.K. is looking to convert to a 4 year undergraduate program and 4 year PhD program in order to be more compatible with the Bologna plan. At the moment though, the easiest way for American students to study in the U.K. may be to participate in an exchange program.

Swiss and German systems are very similar. The language of instruction is English, and foreign students do not have the funding problems seen in the U.K. In Germany one applies for graduate programs in a manner similar to the U.S., and students without master's degrees may be able to have their undergraduate work evaluated and compared to the Diplom program there. If there is a significant number of courses missing, a fourth year extension with a Bachelor's stipend is possible. 96% of students graduate, with 90% going on to astronomical jobs.

In Switzerland, one contacts the faculty member with whom they would like to work directly in order to apply for graduate school; it is much more like the post-doc application process here. A master's is necessary for admission, however. After completing the PhD, foreign students are eligible for one year of funding to complete a post-doc abroad.

Interview with Craig Wheeler

2008-01-13T14:14:00.001-05:00

I edited the transcript link so that it hopefully works now...

Interview transcript (.txt)

Dr. Craig Wheeler, a professor at the University of Texas at Austin, is in his second year as AAS president, having begun his term in June 2006. His term ends in June of this year, at which time Dr. John Huchra of the Harvard-Smithsonian Center for Astrophysics will take over. During his tenure as president, Dr. Wheeler has tried to give the society's council a more active role, transforming them from what he described as a "rubber stamp group". He wants them to have a more long-range focus, and look to where the society should be going.

Dr. Wheeler has also recognized the information revolution that has been available via the internet. He cited astro-ph as something that came out of nowhere, but is an integral part of the daily life of most astronomers. He has appointed a committee to research how this connectivity may be best used to further the astronomical community. Contributions of this committee include the creation of a wiki on the AAS site, explaining how various agencies and committees function. They hope that this wiki will make understanding the politics behind astronomical research easier.

When asked about the privatization of astronomical research, as corporations such as Google become more and more involved, Dr. Wheeler responded that their impact was extremely positive. Although he did not see private funding supplanting governmental funding, he still found the contributions of private corporations key. Many astronomers have been disgruntled about government funding in recent years, a problem which Dr. Wheeler does not feel will change significantly with the upcoming presidential election. NASA administrator Michael Griffin suggested, while at lunch with Dr. Wheeler, that there are such extreme pressures from both sides, that no dramatic changes may be made to NASA policy even with administrative alterations.

Dr. Wheeler pointed out that although he would certainly like to find out the presidential candidates' positions on scientific policy, science is not the number one issue facing the nation right now. Issues such as healthcare and war are more important, although the public would certainly benefit if they were more exposed to scientific theories.

As globalization continues, Dr. Wheeler thinks collaborative efforts will play larger and larger roles in astronomy. More nations are becoming involved in astronomical research, and the influx of foreigners to the American astronomical community may decrease as these other countries strengthen there science programs. Large collaborations will be vital to maintain ties between researchers as the community expands.

In the next few decades, Dr. Wheeler thinks that the largest areas of research will be in the fields of galaxy formation, stellar evolution, and exoplanets. He points out that JWST will play a large role in the study of galaxies, while increased computational power will be key in unlocking the present mysteries seen in many subfields. He expects more giant leaps to be taken in the field of exoplanets, and hopes that soon Earth-like planets will be detected.

Upon being asked about what undergraduates should do to ensure a successful future in astronomy, Dr. Wheeler said "set your sights high and work hard". He suggested that physics programs may provide stronger backgrounds for undergraduates than purely astronomy ones, and recommended that students find congenial environments in which to work.

Interview with Craig Wheeler

2008-01-12T11:43:00.000-05:00

I managed to get an interview with Craig Wheeler yesterday (SPS wanted an interview with one of the society's officers). I was amazed I found him, given how busy the AAS president must be during the meeting. I haven't posted anything about the interview yet, because I'm waiting for my roommate to transcribe it for me, but will hopefully have it up by tomorrow. I'm in transit for all of today, so there is no chance of it being posted before then. I also may put up information about going to grad school in Europe; I went to a session on that topic yesterday.

The list of questions I asked includes:

-What does the AAS president do? What do you feel were your most significant contributions to the astronomical community as president?

-At this meeting, many discoveries were announced via press releases and talks. What do you feel were the most important discoveries this year?

-Many corporations, such as Google, seem to be interested in funding astronomical endeavors. How do you feel the privatization of astronomical efforts affects the community? Is such privatization necessary with current funding cuts?

-How will the upcoming presidential election impact the future of the astronomical community? What changes would you like to see in scientific policy?

-What issues do you think the next generation of astronomers will have to face?

-What do you think the big areas of research will be in the next few decades?

-What recommendations do you have for current undergraduate students who wish to become successful in the field?

Last AAS press conferences

2008-01-11T15:44:00.000-05:00

Here is the audio of the last AAS press conferences (wma format):

Supernovae and Super Neutron Stars

Supernova Dust Formation
Most Massive Neutron Star
Questions

The Million Mass Cloud and questions

Surprising Dust Formation in Supernovae

2008-01-11T11:27:00.000-05:00

Nathan Smith and his collaborators at the University of California at Berkeley have discovered dust formation in supernova SN 2006jc. It is only one of four cases known of dust forming in supernovae.

Two years prior to the supernova in 2006, the progenitor star was seen to have a very large outburst, ejecting a large amount of mass from its surface. Ryan Foley, also of the University of California at Berkeley, proposes that the star recently transitioned from a Luminous Blue Variable (LBV) star, a star in a brief unstable phase of stellar evolution, to a Wolf-Rayet star, a hot, highly-evolved star that has shed its stellar envelope.

It is thought that the blast wave from the 2006 supernova smashed into the shell ejected two years before. At this time, dust was created. Smith explained the process as being similar to the dust settling after fireballs that are so often shown in Hollywood movies.

The dust, created 50 days after the supernova (dust normally forms several hundred days later), left three different signatures. First, the supernova faded more rapidly than other supernovae of its type, a sign of the formation of dust that blocked the light. Secondly, there was infrared emission from the hot dust. An infrared excess, due to ultraviolet photons exciting electrons in the dust, was observed for a short period of time before disappearing. Lastly, the emission from the far side of the supernova was blocked. Because more dust lies between Earth and the far side of the supernova than the Earth and the near side of the supernova, the light curve of the supernova was lopsided, giving more emission on the blue-shifted (near) side. Such asymmetric line profiles have only been observed twice before, and never before in this type of supernova.

Huge Hydrogen Cloud Heads for Milky Way

2008-01-11T11:25:00.000-05:00

In less than 40 million years, a giant cloud of hydrogen gas will impact the Milky Way, and may set off a spectacular burst of stellar fireworks. “The leading edge of the cloud is already interacting with gas from our galaxy,” according to Felix Lockman of the National Radio Astronomy Observatory (NRAO), part of a team of scientists who used the Green Bank Telescope (GBT) to study the cloud.

Called Smith’s cloud after the astronomer who discovered it in 1963, it is 11,000 light-years long, 2,500 light-years wide, and is a million solar masses. At a mere 8,000 light-years from our galaxy’s disk, it is heading toward the galaxy at 150 miles per second.

“This is most likely a gas cloud left over from the formation of the Milky Way or gas stripped from a neighbor galaxy. When it hits, it could set off a tremendous burst of star formation. Many of these stars will be very massive, rushing through their lives quickly and exploding as supernovae. Over a few million years, it’ll look like a celestial New Year’s celebration, with huge firecrackers going off in that region of the Galaxy,” Lockman said.

The cloud, 30 times the width of the full moon on the sky, is made entirely of gas. “Our galaxy will get a rain of gas from this cloud, then in about 20 to 40 million years, the cloud’s core will smash into the Milky Way’s plane,” Lockman explained. The collision may trigger a period of rapid star formation fueled by the new gas and the shock from the collision.

Critical Chemicals for the Creation of Life Found in Distant Galaxy

2008-01-11T10:30:00.004-05:00

For the first time, astronomers have detected methanimine and hydrogen cyanide, molecules vital in the creation of life-forming amino acids, in a galaxy 250 million light years away. Using the Arecibo radio telescope, a team led by Arecibo astronomer Christopher Salter made the discovery in galaxy Arp 220, an ultraluminous starburst galaxy.

The molecules, which make the most simple amino acid, glycine, when combined with water, were found by searching for radio emission at specific frequencies. “We weren’t targeting any particular molecule, so we didn’t know what we were going to find—we just started searching, and what we found was incredibly exciting,” said Tapasi Ghosh, an Arecibo astronomer.

“The fact that we can observe these substances at such a vast distance means that there are huge amounts of them in Arp 220,” said Emmanuel Momjian, a former Arecibo astronomer, now at the National Radio Astronomy Observatory. “It is indeed very intriguing to find that the ingredients of life appear in large quantities where new stars and planets are born.”

Neutron Stars More Massive Than Previously Thought

2008-01-11T10:30:00.002-05:00

The discovery of a neutron star of 1.9 solar masses changes the predicted range of allowed masses for these stars. Previously, it was thought that neutron stars needed a maximum mass between 1.6 and 2.5 times the mass of the sun to collapse and form black holes. However, the new research indicates that the needed mass is most likely between 1.9 and 2.7 solar masses.

With a mass typically around 1.4 times the mass of the sun, radii of neutron stars are around 10 to 16 kilometers, and have densities of billions of tons per cubic centimeter. According to Paulo Freire, an Arecibo astronomer who found the mass of the neutron star, the star is like one single, giant atomic nucleus with about 460,000 times the mass of the Earth.

“The matter at the center of the neutron stars is the densest in the universe. It is one to two orders of magnitude denser than matter in the atomic nucleus. It is so dense we don’t know what it is made out of,” said Freire. “For that reason, we have at present no idea of how large or how massive neutron stars can be.”

The neutron star, part of a binary pulsar called M5 B in the globular cluster M5, was observed by Friere over a period of nearly six years, from June 2001 to March 2007. Pulsations of light from the pulsar, caused by the emission of magnetic radiation the magnetic pole of a strongly magnetized neutron star, were found to occur every 7.95 milliseconds. The precise timing information allowed astronomers to accurately measure the orbit of M5 B around its companion, and in turn measure the neutron star mass.

Freire notes that there are indications that there may be a significantly more massive pulsar, PSR J1748-2021 in NGC 6550, weighing approximately 2.7 solar masses. However, because this pulsar is such an extreme outlier, astronomers are very cautious in concluding that the neutron star mass range extends to 2.7 solar masses. They intend to do more careful observations, and hope to better constrain the star's mass before drawing official conclusions.

First Ground-Based Detection of Extrasolar Planet Atmosphere

2008-01-11T10:30:00.000-05:00

Using the Hobby Eberly Telescope (HET), Seth Redfield of the University of Texas at Austin has made the first ground-based detection of the atmosphere of an extrasolar planet. This finding is an incremental step in the search for life in the universe, as it likely precedes the detection of an Earth-like planet.

“What we all want to find is a planet with an Earth-like atmosphere,” Redfield said.

The planet Redfield found orbits HD189733, a star 63 light-years away. The planet is 20 percent more massive than Jupiter, and orbits its parent star with an orbital radius only 1/10 the size of Mercury’s. The only previously known extrasolar planet with an atmosphere was discovered with a now-broken instrument on the Hubble Space Telescope.

The planet was detected as it transited in front of its host star, blocking 2.5 percent of the star’s total light. The planet’s atmosphere blocked 0.3 percent of the star’s light. “If the planet has no atmosphere, it will block the same amount of light at all wavelengths. However, if the planet has an atmosphere, gasses in its atmosphere will absorb some additional light,” said Redfield. Sodium was detected in the atmosphere of the planet, suggesting it is very abundant, and it is expected that the detection of other less-abundant elements will follow, such as potassium and hydrogen.

“It is just breathtaking how fast the progress in the field of exoplanets is,” said Redfield’s collaborator, Michael Endl. “We have arrived at a point where we can study the composition of the atmospheres of ‘hot Jupiters’ in great detail. The HET is not only a planet finder now, but also a great tool to examine the atmospheric features of transiting extrasolar planets with unprecedented resolution. I can’t wait to see how the results for the other planets will compare to our initial findings.”

Habitable Zones Around Nearby Stars

2008-01-11T09:40:00.000-05:00

A team from Georgia State University is estimating what they call the “habitable real estate” around nearby stars, the area in which a planet could sustain liquid water. The RECONS (Research Consortium of Nearby Stars) group uses telescopes at the Cerro Tololo Inter-American Observatory to study the habitable zones around these stars.

“We want to know how much habitable area there is associated with each stellar system, and for each different class of star founds among the Sun’s neighbors,” according to Justin Cantrell, who is leading the research.

Observed brightnesses of the stars at optical and infrared wavelengths and the star’s distances are used to find the stars’ intrinsic luminosities, colors, and distances, which lead to estimates of the stars’ temperatures and sizes. The team is the first to look at the zones around all nearby stars, regardless of stellar size or temperature.

“Once we have good values for the temperatures and sizes of the nearby stars, we can estimate how hot planets will be at different distances from the stars,” Cantrell explains. “We consider those stars that would have surface temperatures suitable for liquid water to be in the traditional habitable zone.”

Red dwarf stars, small stars significantly cooler than the sun, were of particular interest to the group, as they comprise 70% of the galactic population. Although there are 44 red dwarfs and only 3 G (sun-like) stars within 16.4 light years, all of the red dwarf habitable real estate added together did not equal the habitable zone of even one sun-like star.

Cantrell’s advisor, Todd Henry, does not think that they should give up on finding habitable planets around red dwarfs yet. “You never know where the liquid water may turn out to be”, Henry said. We know there is liquid water on Saturn’s moon Enceladus, and suspect water on Jupiter’s moon Europa, both far removed from the prime real estate region in the solar system.

The team is also interested in the habitable zones of multiple-star systems; roughly half of all sun-like stars have binary companions, while one-third of red dwarfs do. In many systems these stars are separated by enough distance to leave large amounts of good real estate around each star. In the Alpha Centauri star system, a triple star system that is the closest star system to Earth, two of the stars may interfere with each other’s habitable zones, but the affected region is less than 1% of their habitable zones. The other star, Proxima Centauri, is completely unaffected, leaving three promising locations for life in the system.

Audio of today's press conferences

2008-01-10T16:32:00.001-05:00

Audio in WMA format again of press conferences for many of the press releases previously posted

Dark Matter and Cosmology

Dark Matter Map Reveals Violent Lives of Galaxies
Double Einstein Ring
Questions

Special Strange Stars

Quadruple Stars
The Moth
Proxima Centauri
Questions

New Observatories and instruments

Hobby-Eberly and HETDEX
Magdalena Ridge
SDSS III
Questions

Black Hole Briefing II

Light Echoes Caused by Black Holes
Rapidly Spinning Black Holes
Supermassive Black Holes in Bulgeless Galaxies
Questions

Sustaining Life Around A Small Star: The Likelihood of Life Around Proxima Centauri

2008-01-10T16:30:00.000-05:00

As part of the “Living with a Red Dwarf Program”, Edward F. Guinan of Villanova and his collaborators have studied red dwarf star Proxima Centauri, and analyzed its habitability. Proxima Centauri, the nearest star to the sun, is part of a triple star system that is 4.24 light-years from Earth. It is believed to have evolved at the same time as the other two stars in the system.

Red dwarfs are extremely cool stars; because of this, the habitable zone of Proxima Centauri is much closer to the star than the habitable zone in our solar system, at 0.04-0.10 AU. Edward Guinan of Villanova University, and his team, found that any planet orbiting within the habitable zone would be tidally locked with one hemisphere continuously illuminated, while the opposite side would be in constant darkness. Without a significant atmosphere, such a planet would be hot on the starlit side and very cold on the dark side.

Joshi et al. in 1997 discovered that it is possible for a tidally-locked planet close to its host star to retain an atmosphere, as long as its atmosphere is sufficiently thick (pressure greater than 0.5 Bar). In this case, circulation would help to even out the temperature on the planet’s surface.

High precision astronomy and radial velocity observations, done by Benedict et al. in 1998, and Kuerster et al. in 1999 do not show evidence for planets of Jupiter mass or more. However, Guinan and team theorize that planets the size of Neptune or smaller may exist. Because the system contains 1.3-2.6 times the metals of the sun, terrestrial planet formation is even more favorable in the system than in our own solar system.

Although terrestrial planets may be more common in the Proxima Centauri system, they must hold out for the first 2 billion years of the system’s existence; during this time period the star would have 1-2 major flares per day, and a thick atmosphere (pressure greater than 0.5 bars) would be needed to protect life.

Rapidly Rotating Black Holes Observed

2008-01-10T16:20:00.000-05:00

A new study using Chandra results suggests that supermassive black holes are spinning very rapidly. The whirling of the black holes drives extremely powerful jets which drive large amounts of energy into their environment and affect galaxy growth.

In the Chandra study, data from nine giant galaxies with large disturbances in their gaseous atmospheres were compared to theoretical models of jets produced by rotating supermassive black holes. “We think these monster black holes are spinning close to the limit set by Einstein’s theory of relativity, which means that they can drag material around them at close to the speed of light,” said Rodrigo Nemmen, of the Universidade Federal do Rio Grande do Sul in Brazil and The Pennsylvania State University.

Rapidly spinning black holes make spacetime itself rotate according to the theory of general relativity. This effect, coupled with gas spiraling toward the black hole, may produce a helical magnetic field, that flings a large fraction of inflowing gas away from the black hole in the form of a high-speed jet.

The black holes in the study were found to spin at 90-99.8% of their maximum spin rate, via measurements of the amount of material flowing into the black hole and amount of jet outflow. This result will aide in the understanding of how black holes acquire spin during cosmic evolution, and may help explain the source of the incredible jets.

"Light Echos" Produced by the Gravity of Rapidly Spinning Black Holes

2008-01-10T16:07:00.000-05:00

Astromers Keikgo Fukumura and Demosthenes Kazanas predict that severe warping of spacetime in the vicinity of black holes can produce light echoes. “If the black hole is spinning fast, it can literally drag the surrounding space, and this can produce some wild special effects,” says Fukumura.

The warping of spacetime around the black hole causes the trajectory of the photons to bend. This effect may be observed when hot spots in the disks of hot gas around black holes emit random bursts of x-rays. The arrival of the x-ray photons is then delayed depending upon the positions of the x-ray flare, the black hole, and Earth.

However, if the black hole is rotating very rapidly, the delay between the photons is constant, regardless of the source’s position. According to Fukumora and Kazanas, for rapidly spinning black holes, up to 75 percent of x-ray photons arrive at the observer after completing a fraction of one orbit around the black hole, while the remaining photons travel the exact same fraction plus one or more full orbits, making an echo.

Echos would appear as Quasi-Periodic Oscillations (QPOs). An example of a QPO with a period of 10 seconds might exhibit peaks at 9, 21, 30, 39, 51, and 61 seconds. Fukumora and Kazanas predict QPOs at a rate of 1400-1500 per second for a 10 solar mass black hole, or 140-150 per second for a hundred solar mass black hole.

Detecting these QPOs can help astronomers constrain the mass of the black hole with great accuracy and precision. The QPOs also indicate that the spin of the black hole is above 90% of the maximum spin. It is hoped that the next generation of x-ray telescope will be able to detect these light echos.

Thin Galaxies with Fat Black Holes

2008-01-10T15:01:00.000-05:00

Previously, it was thought that all galaxies except the slender, bulgeless spirals harbor supermassive black holes at their core; bulges were thought to be required for these black holes to grow. New Spitzer observations are calling this theory into question. A survey of 32 flat and bulgeless galaxies revealed that monstrous black holes lie in seven of them. This suggests that dark matter could play a role in the formation of supermassive black holes, and implies that galaxy bulges are not necessary for black hole growth.

“This finding challenges the current paradigm. The fact that galaxies without bulges have black holes means that the bulges cannot be the determining factor,” said Shobita Satyapal of George Mason University. “It is possible that the dark matter that fills the halos around galaxies plays an important role in the early development of supermassive black holes.”

For years scientists thought that supermassive black holes at galactic centers were inherently connected to their host galaxy; they are typically 0.2 percent of the mass of their galaxies’ bulges. However, in 2003, a relatively “lightweight” supermassive black hole was found in a galaxy lacking a buldge. The discovery of seven more black holes in thin galaxies with minimal bulges further weakened the “bulge-black hole” theory. Obscuration by dust was most likely the reason for the lack of prior detection; infrared imaging, such as that of Spitzer, can penetrate the dust, and was able to detect the black holes.

With the “bulge-black hole” theory called into question, alternative relationships must be investigated. Dark matter may somehow determine the mass of a black hole early on in the development of the galaxy. “Maybe the bulge was just serving as a proxy for the dark matter mass—the real determining factor behind the existence and mass of a black hole in a galaxy’s center,” said Satyapal.

New Image of Centaurus A Reveals X-ray Jets

2008-01-10T15:00:00.000-05:00

A new Chandra image of galaxy Centaurus A reveals prominent x-ray jets of high energy particles powered by an active supermassive black hole, as well as numerous smaller black holes in binary star systems. The jets extend to the outer reaches of the galaxy, with one jet extending for 13,000 light years and another shorter jet in the opposite direction. Such jets are believed to be important vehicles for transporting energy from the black hole to the much larger dimensions of a galaxy, and affecting the rate at which stars form there.

High energy electrons spiraling around magnetic field lines produce the x-ray emission from the jet and counterjet. Constant reacceleration must be provided to the electrons in order to keep up a steady rate of emission. Knot-like features in the jets show where this acceleration is occurring, and provide clues that may help understand the process of acceleration of the electrons to near-light speeds. The inner part of the jet near the black hole is dominated by these knots, which are most likely due to shock waves caused by the jet. The cause of acceleration in the outer portions of the jets is unknown.

The image of Centaurus A, the nearest galaxy to Earth that contains a supermassive black hole, was made with ultra-deep observations with more than seven days of observing time. Hundreds of other point-like sources are revealed by the Chandra image, many of which are X-ray binaries that contain a stellar mass black hole and a companion star. Determining the population and properties of these binaries should help scientists better understand the evolution of massive stars and the formation of black holes.

Hobby-Eberly Searches for Dark Energy

2008-01-10T14:32:00.001-05:00

Upgrades to the Hobby-Eberly Telescope (HET) are designed to facilitate an experiment to determine the nature of dark energy, the mysterious force that is causing the universe’s expansion to accelerate. The upgrades include a new top end to widen the telescope’s field of view, and a new instrument entitled VIRUS (Visible Integral-field Replicable Unit Spectrograph). VIRUS will be placed at the top of the telescope’s prime focus.

The creation of VIRUS involves an “industrial scale replication” of a relatively inexpensive unit spectrograph. Using this “new mode for building big instruments”, VIRUS will be created out of 145 of these units. Once in place, VIRUS will map the positions of more than a million galaxies over a three-year period, in an area of over 400 square degrees on the sky (2000 times greater than the size of the moon).

VIRUS will enable the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) to study the sky map for evidence of “baryonic acoustic oscillations” (BAOs). BAOs are a pattern of sound waves imprinted on the universe at a very early time after the Big Bang. Changes in the patterns of BAOs will be observed by studying galaxies at varying distances, providing evidence of how dark energy has changed over time. “Dark energy is one of the most important questions facing physics and astronomy,” said Gary Hill of the University of Texas at Austin. “We are really completely ignorant of the nature of dark energy. As we explain, it may not be dark and it may not be energy.”

New Science with the Magdalena Ridge Observatory

2008-01-10T14:05:00.001-05:00

The Magdalena Ridge Observatory (MRO) is comprised of two distinct state of the art telescope facilities, at an elevation of 10,500 feet in the mountains west of Sorocco New Mexico. The 2.4m telescope had its first light on October 31, 2006, and primarily aims to physically characterize small solar system bodies and support the nation’s Space Situational Awareness (SSA) efforts by monitoring and characterizing resident space objects in close proximity to Earth. Funded by the Department of Defense, it is part of NASA’s Near Earth Object program, which follows-up potentially hazardous asteroids. With a tracking rate of 15 times the rate of traditional telescopes, it can also be used to support missile tracking studies.

The second portion of the MRO is an interferometer, to be made of 10 1.4-meter telescopes. It will be capable of producing objects at over 100 times the resolution of the Hubble Space Telescope. The primary scientific objectives include deepening our understanding of the earliest stages of star and planet formation, the final stages of a star’s life, and the environs of black holes in the center of nearby external galaxies.

Sloan Digital Sky Survey Searches for Signs of Dark Energy and More

2008-01-10T13:54:00.000-05:00

After eight years of incredible discoveries by the Sloan Digital Sky Survey (SDSS and SDSS-II), a third program, SDSS-III, has been announced. This new program, composed of four coordinated surveys will revolutionize the study of the distant universe, the Milky Way galaxy, and giant planets orbiting other stars. It will run from mid-2008 to mid-2014, using the 2.5-meter telescope at Apache Point Observatory in New Mexico.

The cosmological measurements in SDSS-III could rewrite fundamental physics, either pinning down the properties of an exotic form of energy that fills the universe or showing that Einstein’s theory of gravity fails at cosmological distances,” explains Daniel Eisenstein of the University of Arizona and director of the newly formed collaboration.

The largest of the four surveys, the Baryon Oscillation Spectroscopic Survey (BOSS), will measure the expansion of the universe with unprecedented precision. Cosmologists attribute this acceleration to “dark energy”, which pervades otherwise empty space and exerts repulsive gravitational force. It could be the cosmological constant proposed by Albert Einstein in 1917—the same constant that Einstein later called the biggest blunder of his career—or it could be a new form of energy that evolves with time. High precision is needed to distinguish these possibilities.

SDSS achieved one of the first clear detections of “baryon acoustic oscillations” in 2005, a feature imprinted on the clustering of galaxies by sound waves that traveled in the early universe. BOSS will use this feature to measure cosmic distances. “Our measurements should reach one-percent accuracy and extend to distances of ten billion light years, giving us strong tests of dark energy theories.”

While more sensitive instruments are being constructed for BOSS, SDSS-III will carry out a one-year extension of SEGUE, an SDSS-II survey mapping the outer Milky Way. The new APOGEE survey will also study the Milky Way using an infrared instrument, which will penetrate the dust in the center of the Milky Way, revealing more stars in the heavily-obscured galactic center. This survey will cover 100,000 stars across the galaxy.

MARVELS, another component of SDSS-III, will search more than 10,000 stars for orbiting giant planets, a three-fold increase on the number searched by all other telescopes to date. Many of these giant planets are in elliptical orbits much closer to their parent stars than gas giants in our solar system. “By systematically monitoring such a large number of stars,” says Jian Ge of the University of Florida, “MARVELS will address two of the biggest questions in planetary science: how do giant planets form, and why are so many in such unusual orbits?”

Circumstellar Dust Takes Flight in “The Moth”

2008-01-10T11:30:00.001-05:00

With a wingspan of 22 billion miles, young star HD 61005, nicknamed “The Moth” is revealing new information about the formation and evolution of planetary systems. The star, approximately 100 million years old, is surrounded by a dust disk, giving it the wing-like shape. These disks are typically flat, pancake-shaped structures where planets can form.

Hubble images of “The Moth”, taken as part of a survey of sun-like stars, reveal that some disks sport surprising shapes. “We think HD 61005 is plowing through a local patch of higher-density gas in the interstellar medium, causing material within HD 61005’s disk to be swept behind the star. What effect this might have on the disk, and any planets forming within it, is unknown,” according to Dean Hines of the Space Science Institute in Corrales, New Mexico, part of the Hubble team that discovered the disk.

According to Hines, this possible collision is “unusual, because we don’t expect very much interstellar material to be in the solar neighborhood. That’s because the area through which our sun is moving was evacuated within the past few million years by at least one supernova, the explosion of a massive star. Yet, here’s evidence of dense material that’s very close, only 100 light-years away.”

The environment in which a star forms influences its prospects for planetary formation. Hubble images have indicated that the harsh stellar radiation from the Trapezium stars in the Orion Nebula, for instance has altered some disks. It is not clear, however, what affect the passage of a star through a cloud similar to the one in which HD 61005 finds itself has on planetary formation. Passage through dense interstellar medium may have affects on the atmospheres of evolving planets.

Tightly Bound Quadruple Star System May Reveal Stellar Evolution Secrets

2008-01-10T11:30:00.000-05:00

An extremely rare quartet of stars orbiting each other within a region smaller than Jupiter’s orbit around the Sun have been revealed by data from the Keck and Canada-France-Hawaii telescopes on top of Mauna Kea. The spectrum of the system, called BD-22^o5866”, reveals four distinct stars arranged in two pairs.

Dr. Evgenya Shkolnik of the University of Hawaii’s Institute for Astronomy and the NASA Astrobiology Institute found this system with collaborators while monitoring several hundred nearby low-mass stars. At the time of observations, two of the stars were orbiting each other at 133 km/s (300,000 mph), while the second pair was moving at 52 km/s (120,000 mph). Using the speeds and star masses, astronomers were able to constrain the maximum size of their orbit. The faster pair orbit each other with a radius of at most 0.06 AU (6% of the distance between the Earth and the Sun), while the second pair orbit each other at a radius of 0.26 AU. The two pairs are separated by an orbital radius of only 5.8 AU.

“The extraordinarily tight configurations of this stellar system tells us that there may have been a single gaseous disk that forced them into such small orbits within the first 100,000 years of their evolution, as the stars could not have formed so close to one another. This is the first evidence of a disk completely encompassing four stars,” says Dr. Shkolnik. “It is remarkable how much a single stellar spectrum can tell us about both the present and past of these stars.” Because most stars from as part of multiple-star systems, this quadruple system could provide information key to unlocking the mysteries of stellar evolution.

New Hydrogen Clouds Discovered in M81 Galaxy Group

2008-01-10T10:30:00.001-05:00

A new image of hydrogen clouds in the M81 group of galaxies has been released, revealing five never before seen clouds. The image, taken with the Green Bank Telescope, shows the group of galaxies that lies 11.8 million light-years of Earth. The galaxies are gravitationally interacting with each other, as seen by gas streaming between the galaxies. Each newly discovered cloud contains between 14 and 57 million times the mass of the sun, similar to clouds in the Milky Way. Astronomers who have analyzed the image conclude that they are likely remnants of earlier galaxy interactions.

The research team includes Katie Chynoweth, a graduate student at Vanderbilt University, Glen Langston of the National Radio Astronomy Observatory (NRAO), Min Yuan of the University of Massachusetts, Felix J. Lockman of the NRAO, Kate Rubin of Lick Observatory, and Sarah Scoles of Cornell University.

New VLA Images Unlocking Galactic Mysteries

2008-01-10T10:30:00.000-05:00

Using more than 500 hours of observation with the Very Large Array (VLA) radio telescope, an international team of astronomers has produced a collection of high-quality images of 34 galaxies, yielding insights into the complex structure of the galaxies, how they form stars, motions of their gas, and the relationship of “normal” matter to unseen “dark matter”. The galaxies, at distances between 6 to 50 million light-years from Earth, were observed as part of The HI Nearby Galaxy Survey (THINGS), a study of neutral hydrogen gas.

“Studying the radio waves emitted by atomic hydrogen gas in galaxies is an extremely powerful way to learn what’s going on in nearby galaxies. The THINGS survey uses that tool to provide sets of images of the highest quality and sensitivity for a substantial sample of galaxies of different types,” said Fabian Walter of the Max-Planck Institute for Astronomy.

Many of the galaxies studied in the THINGS survey have also been observed in other wavelengths, including in Spitzer infrared images and GALEX ultraviolet images. The combination provides an unprecedented resource for unraveling the mystery of how a galaxy’s gaseous material influences its overall evolution.

The study has yielded numerous scientific payoffs, allowing the investigation of how star formation processes differ in large spiral galaxies and dwarf galaxies, as well as the rotational motion of galaxies and non-circular random motions within the galaxies. The motion measurements provide new information about the dark matter in the galaxies. “The non-circular motions revealed by the THINGS observations turn out to be too small to solve a long-standing problem in cosmology, namely the inability of state-of-the-art computer simulations to describe the distribution of dark matter in disk galaxies. It was thought that random motions could explain that inability, but our data show otherwise,” Erwin de Blok, of the University of Cape Town, explained.

The images revealed what Elias Brinks called a “stunning complexity of structures in the tenuous interstellar medium of the galaxies,” including large shells and “bubbles”, most likely caused by multiple supernova explosions of massive stars. By analyzing these structures, astronomers hope to better understand the differences in star formation processes in varied types of galaxies.

The new survey also showed that “the gas in galaxies in the early Universe is much more ‘stirred up,’ possibly because galaxies were colliding more frequently then and there was more intense star formation causing material outflows and stellar winds,” explained Martin Zwaan of the European Southern Observatory. The information about the gas in the more distant galaxies came through non-imaging analysis.

Only a small part of the survey has been analyzed, and it expected that much more will be learned about galaxies and how they evolve in further analysis.

Dark Matter Map Reveals Violent Lives of Galaxies

2008-01-10T10:00:00.000-05:00

Using the Hubble Space Telescope, astronomers have been able to dissect one of the largest structures in the universe as part of a quest to understand the violent lives of galaxies. It has provided indirect evidence of the presence of dark matter, tugging on galaxies in a supercluster of over 1000 galaxies. The Advanced Camera for Surveys has mapped the invisible dark matter scaffolding of the supercluster Abell 901/902, as well as the detailed structure of the galaxies imbedded in it.

Led by Meghan Gray of the University of Nottingham and Catherine Heymans of the University of British Colombia, an international team analyzed theses images as part of the Space Telescope Abell 9091/902 Galaxy Evolution Survey (STAGES). The survey covers one of the largest areas of the sky ever observed by Hubble, taking over 80 images to complete a field the size of the full moon.

The study found that four separate galaxy clusters exist within the supercluster, where dark matter has pulled into dense clumps totaling 100 trillion solar masses. The areas correspond to the location of hundreds of old galaxies that experienced a violent history in their passage from the outskirts of the supercluster into these dense regions.

“Thanks to Hubble’s Advanced Camera for Surveys, we are detecting for the first time the irregular clumps of dark matter in this supercluster,” Heymans said. “We can even see an extension of the dark matter toward a very hot group of galaxies that are emitting x-rays as they fall into the densest cluster core.”

The map was created by measuring the distorted shapes of 60,000 faraway galaxies, distorted by the massive gravitational field of the dark matter in the supercluster. The distortion was then used to reconstruct the dark matter distribution to create a map 2.5 times sharper than a previous ground-based survey of the supercluster.

The environment of supercluster galaxies is vastly different than that of galaxies in less crowded environments. “We’ve known for a long time that galaxies in crowded environments tend to be older,, redder, and rounder than those in the field,” Gray said. “Galaxies are continually drawn into larger and larger groups and clusters by the inevitable force of gravity as the universe evolves.” In supercluster environments, a life of violence ensues: galaxies undergo high-speed collisions with other galaxies, the stripping away of the gas that they use to form new stars, and distortion due to the strong gravitational pull of the underlying invisible dark matter.

“In the STAGES supercluster we clearly see that transformations are happening in the outskirts of the supercluster, where galaxies are still moving relatively slowly and first feel the influence of the cluster environment,” said Christian Wolf, an Advanced Research Fellow at the University of Oxford.

Assistant professor Shardha Jogee of the University of Texas in Austin concurs. “We see more collisions between galaxies in the regions toward which the galaxies are flowing than in center of the clusters,” Jogee said. “By the time they reach the center, they are moving too fast to collide and merge, but in the outskirts their pace is more leisurely, and they still have time to interact.”

The team also finds that the outer parts of the clusters are where star formation in galaxies is ceasing, and supermassive black holes at the centers of the galaxies are most active. According to Heiderman, “The galaxies at the centers of the clusters may have been there for a long time and have probably finished their transformation. They are now old, round, red, and dead”.

Double Einstein Ring Dazzles

2008-01-10T09:59:00.000-05:00

Raphael Gavazzi and Tommaso Treu of the University of California, Santa Barbara, and an international team of astronomers have announced the discovery of a never before seen phenomenon: a double Einstein ring. The discovery, observed by Hubble, is part of the ongoing Sloan Lens Advanced Camera for Surveys (SLACS) program.

The rings, caused by gravitational lensing as a foreground galaxy bends background light, create a bull’s-eye pattern. The circular light pattern is caused by the exact alignment of the galaxies, forming an “Einstein ring” around the foreground galaxy. If another background galaxy lies precisely along the same sightline, a second, larger ring will appear. The odds of the occurrence of a second ring are 1 in 10,000. According to Treu, the team observed the ring with Hubble as part of a survey of Einstein rings, thinking it would only be a single ring. They were stunned to find out that it was actually a double.

Such rings can offer insight into dark matter, dark energy, the nature of distant galaxies, and even the curvature of the universe. “Such stunning cosmic coincidences reveal so much about nature. Dark matter is not hidden to lensing,” said Leonidas Moustakas of the Jet Propulsion Laboratory. “The elegance of this lens is trumped only by the secrets of nature that it reveals.”

The foreground galaxy in the system is 3 billion light-years away, while the galaxies that create the inner and outer ring are 6 billion and 11 billion light-years away. The lens was first discovered using the Sloan Digital Sky Survey (SDSS) and was then observed by Hubble, which made the rings clearly visible.

The image allows the distribution of dark matter in the foreground galaxies that create the lens to be precisely mapped. Tommaso finds the fall-off in the density of the dark matter to be comparable to that seen in spiral galaxies. The geometry of the Einstein rings also allowed the team to measure the mass of the middle galaxy to be precisely 1 billion solar masses. This is the first measurement of the mass of a dwarf galaxy at a cosmological distance, at a redshift of z=0.6.

A comparative study of the radius of the rings in a sample of several dozen double rings could produce an independent measurement of the measure of the curvature of space by gravity. This would help determine the matter content of the universe and the properties of dark energy. It is hoped that with next generation space telescopes, at least 50 more rings will be observed.

Supernova Remnants Dance in the LMC

2008-01-10T09:55:00.000-05:00

A peanut-shaped cloud-complex, DEM L316, has been revealed in the Large Magellanic Cloud (LMC). The Gemini South Multi-Object Spectrograph (GMOS) revealed that the nebula was not a single object, but instead is comprised of two distinct gas and dust clouds formed by different types of supernova explosions.

The object, first recognized in the 1970s as a supernova remnant, contains intricate tendrils of gas and dust. The still-expanding complex was likely created a few ten thousands of years ago by more than one type of supernova explosion in this region of the LMC. This observation of the remnant is “a great step forward in efforts to understand this fascinating pair of remnants—whether they represent only a chance alignment on the sky or some as-yet uncovered physical relationship,” according to Dr. Rosa Williams of Columbus State University.

Chandra observations of the object reveal that the chemical compositions of the two shells are very different, strengthening the multiple-supernova hypothesis. The smaller shell contains more iron than the larger one, suggesting it is a Type Ia supernova remnant, while the larger shell is a Type II remnant. Type Ia supernovae are created by the infall of matter from a star onto a white dwarf, while Type II supernovae are created by the collapse of massive stars. The systems had vastly different ages when they “went supernova”, meaning there is very little chance they came from the same system. Although the bubbles appear to be close in the GMOS image, this only occurs due to a chance alignment in our line of sight.

Wednesday Poster Session Chaos

2008-01-10T09:43:00.001-05:00

After the fiasco that was the final day of Seattle last year, you would think that AAS would learn. For anyone who wasn’t there, posters were torn down by staff members at noon (when the session was supposed to last for at least another four hours), and thrown into a pile. Presenting the last day is always horrible anyway, because many people leave early and the session is several hours shorter. Eventually, after many complaints, posters were allowed to be set up outside of the main poster area in rows approximately two feet apart. Most people left after that, and even for those who stayed, the tight poster area made viewing the posters unpleasant.

Wednesday seemed like it was going to be a partial continuation of last year. At 2 p.m., everyone as kicked out of the poster room, telling them they could return at 4. According to the person who told me to leave, they had to set up food, and couldn’t have people in the way while doing it. When several of us protested about the fact that we were supposed to be there for the judging of posters at 3:30, they said select people would be allowed back into the room at that time.

Apparently a large number of complaints led them to reopen the room at a time earlier than previously stated (I only know that it was before 3:30, as I went to the oral sessions thinking I wouldn’t be able to get back in until that time, when my poster was to be judged). Rumor had it that there was some sort of reception for the exhibitioners, and that they tried to kick everyone out because they didn’t want their merchandise to be left in the room unattended.

Astronomy in Popular Culture

2008-01-10T09:40:00.000-05:00

Audio in wma format

Andrew Franknoi discussed the influence of astronomy on popular culture, beginning his AIP Andrew Gemant Award lecture, "From the West Wing to Pink Floyd to Einstein Advertising: Astronomy in Popular Culture", by asking people to turn to their neighbors and name three products that were named after something in astronomy. Astronomical terms are everywhere, from candy (Milky Way, Mars bars) to cars (Saturn, Mercury, Subaru). They repeatedly come up in books, T.V., movies, and music. Apart from the obvious science fiction category, astronomy influences an incredible amount of media, including the West Wing and even a Broadway musical about a football player who must pass his astronomy class. He pointed out following the discussion of the musical that the lowest grade President Bush received at Yale was a D in astronomy, thus explaining the utter dissatisfaction of yesterday’s crowd at Michael Griffin’s talk.

Some of the more unique permeations of astronomy in our culture are in music. John Cage, famous for his 4’33” (four minutes and thirty-three seconds of silence), a piece where numerous radios are all tuned to random stations and turned on, as well as a piece played at a rate of one note per century, created another piece based upon a star catalogue. He placed his staff paper over the catalogue, and marked notes where the brightest stars lay. Others have attempted to follow the idea of Kepler that all planets have different sounds, by making a piece that uses the orbital velocities of the planets beginning on the date of Kepler’s birth as notes.

Two-Phase Planetary Formation

2008-01-09T14:02:00.001-05:00

Hundreds of millions or billions of years after planets initially formed around two unusual stars, Carl Melis of UCLA and collaborators believe another wave of planets and planetesimals formed around these stars. The stars, BP Piscium and TYCHO 4144 329 2 have many signatures of very young stars, including rapid accretion of gas, extending orbiting disks of dust and gas, a large “infrared excess” emission, and in the case of BP Piscium, jets of gas being shot into space.

The spectroscopic signatures of the stars, however, were not those expected of young stars. For instance, young stars typically have large quantities of lithium. However, the lithium in BP Piscium is seen times weaker than expected for a young star of its mass.

“There is no known way to account for this small amount of lithium if BP Piscium is a young star,” Melis said. “Rather, lithium has been heavily processed as appropriate for old stars. Other spectral measurements also indicate it is a much older star.”

Their unusual properties include the fact that 75% of BP Piscium’s and 12% of TYCHO 4144 329 2’s radiant energy is being converted by the dust particles into infrared light, values much higher in comparison to other stars that are known to be not-young.

TYCHO 4144 329 2 orbits a companion star with a mass similar to that of the sun; however, this star appears to be an ordinary old star, with no second phase of planetary formation. Astronomers plan to continue to study both stars using a variety of telescopes and observatories, including Hubble and Chandra, and hope to find similar systems.

First Successful Prediction of Extra-Solar Planet

2008-01-09T14:01:00.001-05:00

Rory Barnes of The University of Arizona in Tucson and his colleagues have announced the correct prediction of the existence of an unknown planet, the first since the prediction of Neptune in the 1840s. The planet, orbiting star HD 74156 at a distance of 200 light years away from Earth, was predicted from observations of two other planets in the system. From observations of orbits in several planetary systems, Barnes and his colleagues found that the orbits of planets tend to be as closely packed as possible without gravitationally destabilizing their orbits. They noted that two planets, “b” and “c”, around HD 74156 had a large gap between them, and assuming that the “Packed Planetary Systems” concept was universal, predicted there must be a planet between b and c in a particular orbit.

“When I realized that six out of seven multi-planet systems appeared ‘packed, I naturally expected there must be another planet in the HD 74156 system so that it, too, would be packed,” Barnes said. “As well as providing a way to predict planet discoveries, the Packed Planetary Systems hypothesis reveals something fundamental about the formation of planets. The process by which planets grow from the clouds of dust and gas around young stars must be very efficient. Wherever there is room for a planet to form, it does.”

Shortly after the discovery of HD 74156 d, a different group of astronomers found a planet orbiting the star 55 CnC, in the orbit Barnes and colleagues predicted. They have also predicted a specific planet orbiting a third system, HD 38529, which they hope will be discovered with future observations.

Antimatter, Low Mass X-ray Binary Connection

2008-01-09T14:00:00.001-05:00

The shape of the mysterious cloud of antimatter in the central regions of the Milky Way has been revealed by the European Space Agency’s (ESA) orbiting gamma-ray observatory Integral to be lopsided. This observation greatly decreases the chances that the antimatter is coming from the annihilation or decay of astronomical dark matter.

Integral was able to observe the cloud due to the annihilation of antimatter as positrons encountered electrons, producing gamma rays. Several theories exist to explain the existence of the positrons. Some astronomers have suggested that exploding stars could produce the positrons through the decay of radioactive elements. It is unclear whether a sufficient number of these positrons would be able to escape the stellar debris to explain the size of the observed cloud.

Previous research suggested that this positron cloud seemed to be spherical and centered on the center of the galaxy, similarly to the expected distribution of dark matter in the same location. It was suggested that dark matter was annihilating or decaying into pairs of electrons and positrons, which then annihilated to produce the gamma rays. However, this theory requires much less massive dark matter particles than most theories predict.

Georg Weidenspointner of the Max Planck Institute for Extraterrestrial Physics and an international team of astronomers found that the antimatter cloud is lopsided with twice as much on one side of the galactic center as the other. Integral also found a population of binary stars off-center, corresponding in extent to the cloud of antimatter. This suggests that hard (high energy-emitting) low mass x-ray binaries are responsible for a large amount of antimatter.

Low mass x-ray binaries (LMXBs) are composed of a neutron star or black hole and a companion star. Because of the intense gravitational field of the neutron star or black hole, the atmosphere of the companion is stripped. As gas spirals toward the center of the neutron star or black hole, it is heated enough to spontaneously produce positron-electron pairs.

According to Weidenspointner, his team’s research indicates that half of all antimatter comes from the LMXBs. The other half could come from similar processes around the galaxy’s central black hole and various exploding stars there. Although the data strongly suggests a connection between LMXBs and antimatter, further investigation is needed to determine if the observed LMXB distribution is real.

Dark Matter in Accretion Disks-- Suggests Major Revisions to Theory of Disk Structure and Luminosity

2008-01-09T11:31:00.002-05:00

Observations of the interacting binary star WZ Sagittae using telescopes at Kitt Peak National Observatory and NASA’s Spitzer Space Telescope suggest that accretion disks are likely to be much larger than previously believed. Accretion disks, disks of hot gas, accumulate around a variety of astronomical objects, from degenerate stars in energetic binary systems to supermassive black holes at the hearts of active galaxies.

Steve Howell and a team of astronomers and educators observed WZ Sagittae as part of the Spitzer-NOAO Observing Program for Teachers and Students. Contrasting results were seen in the optical and the infrared. “The much larger size of the infrared-emitting portion of the accretion disk around WZ Sge was immediately obvious in the data. Our observations strongly imply the presence of dark matter in these structures, which are ubiquitous throughout the universe,” said Howell.

WZ Sge contains a white dwarf (a solar-mass star with the radius of Earth) and a physically larger, but much less massive and cooler companion star. The companion’s surface is stripped by the gravity of the white dwarf, forming an accretion disk around the white dwarf. Variations in the accretion disk cause rapid and large changes in brightness of stars such as WZ Sge, leading to classification as “cataclysmic variables”.

Mid-infrared observations revealed a larger, thicker disk of cool dusty material surrounding much of the gaseous accretion disk discussed in present accretion disk models. The outer disk, containing about as much mass as a medium-sized asteroid, extends 20 times the radius of the outer disk.

In addition to changing perceptions about accretion disk models, the dust disk blocks infrared light emitted by the central object and the inner hot regions of the gaseous disk, causing an underestimation of the luminosity of the central object. “The amount of this underestimation is not yet accurately known from our initial discovery, but may be as large as 50 percent,” Howell says.

Rogue Black Holes Roam the Galaxy

2008-01-09T11:31:00.001-05:00

Simulations of merging black holes indicate that hundreds of rogue black holes weighing several thousand times the mass of the sun could be roaming around the Milky Way. “Rogue black holes like this would be very difficult to spot. Unless it’s swallowing a lot of gas, about the only way to detect the approach of such a black hole would be to observe the way in which its super-strength gravitational field bends light that passes nearby. This produces an effect called gravitational lensing that would make background stars appear to shift and brighten”, according to Vanderbilt astronomer Kelly Holley-Bockelmann.

The research, performed by Holley-Bockelmann, Deirdre Shoemaker and Nicolas Yunes of Penn State, and Kayhan Gultekin at the University of Michigan, focused on modeling intermediate mass black holes. Evidence for supermassive black holes and small black holes less than 100 solar masses is abundant, but only two tentative observations have been made of intermediate black holes that weigh a few thousand solar masses. Theorists predict that globular clusters-- ancient, gravitationally bound groups of 100,000 to a million stars-- should be filled with these intermediate mass black holes.

In the past two years black hole mergers have been modeled using Einstein’s theory of relativity. Surprisingly, these simulations have found that when two black holes rotating at different speeds or of different sizes combine, the new black hole can receive a velocity boost of up to 4000 kilometers per second due to the conservation of angular momentum.

“We realized that basically any black hole merger would kick the new remnant out of a globular cluster, because the escape velocity is less than 100 kilometers per second” said Holley-Bockelmann. When performing simulations of intermediate mass black holes, even the most conservative assumptions suggested that only 30 percent would be retained through the merger epoch. The least conservative assumptions leave only two percent of globular clusters with intermediate mass black holes today. If the roughly 200 globular clusters in the Milky Way did create intermediate mass black holes, this means they are most likely roaming around the Milky Way today.

Most Massive Black Hole Discovered

2008-01-09T11:30:00.000-05:00

Dr. Mauri Valtonen of the University of Turku, Finland has announced the discovery of the most massive black hole known to exist in the universe. It is 18 billion times the mass of the sun, a mass determined by the orbital period and orbital radius of a smaller black hole circling around the large black hole. The result is of particular interest because the binary nature of the black hole allows testing of Einstein’s theory of general relativity for the first time in a strong gravitational field. The test proves Einstein’s theory correct within the accuracy of the measurement.

The black hole system powers the quasar OJ287 at a distance of 3.5 billion light years from Earth. It was first suggested to be a binary system in 1988, when pulses of the light signal were detected. Models of a binary system were confirmed by the correct prediction of pulses in 1994/95 and 2005. Once models were sharpened, an exact date was predicted for the following pulse, occurring on September 13, 2007.

A significant challenge to observing the quasar on September 13 was that in September, the quasar rises in the eastern horizon just before sunrise, making the window of opportunity to observe the quasar only half an hour long before the sky is too bright. For this reason, numerous telescopes across the globe observed the quasar, giving approximately 100 measurements between September and early October. The pulse was found to occur only on September 13, confirming the binary black hole model.

The gravitational field between the black holes warps space time, an effect measurable by the system. This system’s field is extremely strong; stronger than any other field known. Models with spacetime curvature effects were calculated and successfully compared with the timing of the observed pulse. The level of accuracy of the test is only 10% at this time, but future observations, including a January 2016 pulse, can improve this percentage. It is hoped that the space gravitational wave detector, LISA, will be in operation by the 2016 pulse, providing better data than previously obtained.

Earth: Barely Habitable?

2008-01-09T11:05:00.001-05:00

New work by astronomers at the Harvard-Smithsonian Center for Astrophysics suggests that if the Earth were slightly smaller and less massive, it would not have had plate tectonics—the forces that move continents and build mountains. Without plate tectonics, life may never have arisen in this world.

“Plate tectonics are essential to life as we know it,” said Diana Valencia of Harvard University. “Our calculations show that bigger is better when it comes to the habitability of rocky planets.”

Plate tectonics are critical to a planet’s habitability, as they enable complex chemistry and recycle substances such as carbon dioxide, which regulates Earth’s temperature. Carbon dioxide from rocks is release when they melt, returning to the atmosphere from volcanoes and oceanic ridges.

Valencia and her colleagues, Richard O’Connell and Dimitar Sasselov (Harvard) studied super-Earths, planets twice the size of Earth and up to ten times more massive, to see if plate tectonics would be more or less likely on different-sized rocky planets. At larger sizes planets would become gas giants, and would be inhospitable to human-like life.

Super-Earths would be more geologically active than our planet, experiencing more vigorous plate tectonics due to thinner plates under more stress. Even if the planet were twice the size of Earth, it would have similar geography, as rapid plate tectonics allow less time for mountains and ocean trenches to form before the surface was recycled.

Earth itself was found to be a borderline case in this study, which is not surprising given that Venus, at only a slightly smaller size than Earth, does not have plate tectonics. Five super-Earths are known today, and although none have hospitable temperatures, many more are expected to be found in future exoplanet searches. If super-Earths are as common as observations suggest, it is inevitable that some will enjoy Earth-like orbits, making them excellent havens for life.

Protoplanetary Pair Collision

2008-01-09T11:04:00.000-05:00

Object 2M1207B, orbiting a star 170 light-years from Earth, has puzzled astronomers since its discovery; its temperature, luminosity, age, and location do not match up with any theory. Eric Mamajek, of the Harvard-Smithsonian Center for Astrophysics, may have an explanation. He theorizes that two protoplanets collided and merged to form this unusual planet.

2M1207B orbits a 25-Jupiter mass brown dwarf called 2M1207A, a star only 8 million years old. If the planet were also 8 million years old, it should have cooled to less than 1300 Fahrenheit (1000 Kelvin); it is observed to be 2400 degrees F (1600 K), a temperature change that may have been caused by a protoplanetary collision.

“Most, if not all, planets in our solar system were hit early in their history. A collision created Earth’s moon and knocked Uranus on its side,” explained Mamajek. “It’s quite likely that major collisions happen in other young planetary systems too.

The luminosity of 2M1207B is 10 times fainter than expected. Michael Meyer, of the University of Arizona, proposed that the decreased luminosity is because the planet is small, approximately the size of Saturn, and therefore has smaller than expected surface area radiating energy. They derive a radius of 31,000 miles (50,000 km) for the planet, in comparison to 37,000 miles (60,000 km) for Saturn, giving it a mass of 80 times Earth (or one-fourth Jupiter). The only way such a small object could be so hot millions of years after its creation would be if it suffered a recent titanic collision that heated it. It is likely that this collision was formed from a Saturn-sized planet and a planet about three times the size of Earth.

The collision hypothesis leads to multiple testable predictions. Low surface gravity (dependent upon a planet’s mass and radius), may be tested by obtaining a better spectrum of 2M1207B. Others are testing an alternative theory to the small size of 2M1207B, which proposes a dusty disk surrounding the planet. They are looking for signs of polarization in the light from the planet, and think results should be forthcoming within the next several years.

Hidden Quasars Revealed by SDSS

2008-01-09T10:30:00.000-05:00

Quasars are the most luminous objects in the universe, powered by glowing, super-heated gas as it swirls into black holes billions of times more massive than the sun. A new study released by the Sloan Digital Sky Survey (SDSS-II), however, shows that in spite of their size, many of the most energetic quasars may be hidden from view by clouds of gas and dust that block the central black hole.

Using a distinctive spectral signature that even highly obscured quasars show as a marker, the SDSS-II team has found 887 hidden quasars out of a sample of more than a million. “A large survey like SDSS-II is important because quasars are about 10,000 times rarer than are normal galaxies,” explains Reinabelle Reyes of Princeton University. Reyes is the leading author of a paper on these results, entitled “Space Density of Optically-Selected Type 2 Quasars”, to be published in the Astronomical Journal.

“We found that hidden quasars make up at least half of the quasars in the relatively recent Universe, implying that most of the powerful black holes in our neighborhood had previously been unrecognized,” said team member Nadia Zakamska.

Because these results imply that powerful black holes are more common in the last eight billion years of cosmic history than previously thought, black holes turn out to be more efficient in converting energy of in-falling matter into light. The result also has implications for the theoretical models of quasars and the attempt to explain dust and gas distribution around the objects.