Today was another packed day — but that seems to be the norm at the American Astronomical Society (AAS) meeting. The first invited talk echoed a topic that one of today’s press conferences covered: the status of the Fermi Gamma-ray Space Telescope. After three years in orbit, the observatory has identified more than 1,870 gamma-ray objects, including many types that hadn't been discovered before.
The Fermi Gamma-ray Space Observatory's data at its highest energies reveal the outline of the giant gamma-ray bubbles discovered in 2010. // Photo by
The Fermi team also released its view of a largely unexplored region of high-energy astrophysics. These energies are greater than 10 billion electronvolts and extend up to about 300 billion electron volts (visible light has an energy of about 2 or 3 electronvolts). At these energies, the Fermi all-sky map also shows signatures of the
giant gamma-ray bubbles quite clearly. The observatory has found 496 objects in this energy region, and 168 are unidentified. Dave Thompson, Fermi deputy project scientist, added that multiwavelength observations of these unknown objects are crucial to figuring out what they are.
A later press conference focused on (pun intended) the lower end of the electromagnetic spectrum — infrared radiation. Astronomers from four projects released gorgeous images that are also jam-packed with information about star formation. Scientists can observe dust and thus trace the cold raw material that eventually becomes hot stars, and observe young stars forming behind dust clouds, using infrared light.
These four projects look at slightly different wavelengths, and so astronomers can combine data from different telescopes to see great detail. One of the observations presented today did just that: Data from both the European Space Agency’s Herschel satellite and NASA’s Spitzer telescope show current and potential sites of star formation in the Large and Small Magellanic Clouds. The images show detail about 5 light-years across.
Tuesday's second press conference focused on infrared radiation. // Photo by Liz Kruesi.
Another project used Spitzer to survey the Cygnus X star-formation region, which contains all phases of star creation. The released image covers about 25 square degrees (100 times the size of the Full Moon) and contains some 4 million stars. Astronomers with the project specifically were looking for stellar objects in the early stages of formation.
In the same press conference, Xavier Koenig of the Wide-field Infrared Survey Explorer (WISE) released new findings about how massive stars form. His team selected a sample of regions in a 1,000-square-degree mosaic of WISE data, and mapped the distributions of young stars in those regions. The data indicate that stars form in a chain reaction once nearby massive star formation begins.
Tuesday included many other highlights — such as a great talk by Gaspar Bakos of Princeton University. He gave an overview of the extrasolar planet search project HATNet, which has been searching for nearly 10 years for planets passing in front of their stars. It’s found about 30 so far. This project is just one case of small telescopes doing big science. (The automated telescope system is made up of 4-inch and 8-inch scopes across the globe.)
Tomorrow promises another exciting day filled with announcements, poster presentations, and interesting talks.
Read about my recap of
Monday at AAS here.