Sloan Fellowship Will Further U.Va. Astronomer Philip Arras's Research on Giant Planets Beyond Our Solar System

March 13, 2008 — Philip Arras, assistant professor of astronomy, won a 2008 Alfred P. Sloan Research Fellowship, which includes a two-year $50,000 grant. Arras specializes in stellar and planetary physics and theoretical astrophysics.

The Alfred P. Sloan Foundation named 118 outstanding young scientists, mathematicians and economists as research fellows this year. The winners are faculty members at 64 colleges and universities in the United States and Canada who are conducting research at the frontiers of physics, chemistry, computational and evolutionary molecular biology, computer science, economics, mathematics and neuroscience.

“The Sloan Research Fellowships support the work of exceptional young researchers early in their academic careers, and often at pivotal stages in their work,” said Paul L. Joskow, President of the Alfred P. Sloan Foundation. The Sloan Research Fellowships have been awarded since 1955.

The fellows are free to pursue whatever lines of inquiry are of most interest to them, and they are permitted to employ fellowship funds in a wide variety of ways to further their research aims. For a complete list of winners, visit

Arras' research as a Sloan fellow will focus on theoretical studies of extrasolar planets. The last decade has seen an explosion in the number of planets found orbiting nearby stars like the Sun. The most unexpected discovery is the population of “Hot Jupiters”, the gas giant planets found orbiting within ten radii from the parent star. These planets orbit in a harsh environment, subject to the extremes of stellar irradiation, space weather and tidal forces.

Intense observation efforts have gone into finding these exotic worlds, as well as probing their atmospheres and connection to the parent star. Arras' research will address fundamental questions about Hot Jupiter structure and evolution through theoretical modeling of Hot Jupiter interiors and atmospheres. The challenge is that these planets probe new physical regimes not found in planets in our own Solar System.