Monday, December 8, 2008, Joint Physics Colloquium, 4:30 PM, 104 Thaw Hall, PITT

Dr. David Charbonneau

Harvard-Smithsonian Center for Astrophysics

"Detecting Habitable Exoplanets: The Small Star Opportunity"

Abstract:

When exoplanets are observed to eclipse their parent stars, we are granted direct estimates of their masses and radii, and we can undertake studies of their atmospheres. Such systems have profoundly impacted our understanding of giant exoplanets akin to Jupiter or Neptune, yet no transiting examples of rocky exoplanets have yet been found. By targeting nearby low-mass stars, a transit search using modest equipment is capable of discovering planets as small as 2 Earth radii in their stellar habitable zones. The discovery of such planets would provide fundamental constraints on the physical structure of planets that are primarily rock and ice in composition. Moreover, by differencing spectra gathered when the planet is in view from those when it is occulted by the star, we can study the atmospheric chemistry of potentially habitable worlds.