"The thing that hooked me on astronomy was the first time I went to one of these very large, research-grade telescopes. It's just amazing, and is an experience I am eager to share with students."
Assistant professor of physics and astronomy
Gazing up at the night sky, far from the lights of civilization, one can hardly help but ponder how many stars are out there, where they came from and how far the universe can stretch. Four hundred years after Galileo first observed the night sky through a telescope, Assistant Professor of Astronomy Katelyn Allers is finding answers to at least one of those questions.
In her research on how stars and planets form, Allers studies neither. Instead, she focuses on brown dwarfs, which are larger than planets but smaller than stars. "If you want to understand star formation and you want to understand planet formation, it makes sense to study the thing in the middle," Allers says. || Ask the Experts: Katelyn Allers on astronomy
Unlike stars, brown dwarfs can't be seen twinkling in the sky because they are too cool to give off much visible light. They do, however, emit infrared radiation, which can be picked up by telescopes tuned to the longer wavelengths, such as the Spitzer Space Telescope, which was launched in 2003.
As a graduate student at the University of Texas, Allers was part of a research team that used the Spitzer Space Telescope to discover some tantalizing insights to how brown dwarfs form. Stars form when a large cloud of gas and dust collapses on itself. If the cloud has sufficient mass, the collapse triggers nuclear fusion, which then creates the heat and light given off by the star. Brown dwarfs, however, are much smaller than stars. "When brown dwarfs were discovered, it meant we had to come up with different ideas for how very, very low mass stars can form," Allers says. Her research has indicated that despite their low mass, brown dwarfs might form in much the same way as stars.
Studying brown dwarfs can also shed light on planets found outside our solar system. Extrasolar planets are difficult to study because their "sun" — the host star they orbit around - is so bright, it outshines any light coming from the planets themselves. Most brown dwarfs, however, have no host star to mask their light. "We are able to look at things that are really similar to planets without having this pesky host star in the way," Allers says.
She looks forward to taking Bucknell students to large observatories in Hawaii and Chile. "The thing that hooked me on astronomy was the first time I went to one of these very large, research-grade telescopes. It's just amazing, and is an experience I am eager to share with students," she says.
Posted Sept. 22, 2009