Date: Tuesday 04-Feb-2014
Time: 15:00-16:00
Location: CSS 2316
Speaker: Brian Jackson (DTM)
Title: On the Edge: Exoplanets with Orbital Periods Shorter Than a Peter Jackson Movie
The vast majority of gas giant exoplanets with close-in orbits is unstable against tidal decay and may spiral into their host stars in only a few billion years. Moreover, rocky planets with orbital periods of only a few hours would induce stellar radial velocity (RV) signals measurable by current facilities. Motivated by these considerations, I recently led a search for very short-period transiting planets using Kepler data. We found four planetary candidates, with periods as short as four hours, and one candidate was independently discovered and confirmed by follow-up RV observations. This planet, Kepler-78 b, has an Earth-like density but an orbital period of only 8.5-hours and a surface temperature approaching 3,000 K. These potentially rocky planets in orbital periods of only a few hours have opened an exciting, new avenue for exoplanet study but pose severe challenges to theories of planet formation and evolution. In this presentation, I'll discuss our search for very short-period planets and their observational and theoretical implications. I'll describe why the usual origin scenarios for close-in planets may not apply to these candidates and the possibility that they are remnant fossil cores of disrupted close-in gas giants. Whatever their origins, such planets would be particularly amenable to discovery by the planned TESS mission and detailed follow-up.
Brian Jackson -- Carnegie Dept. of Terrestrial Magnetism, Washington DC bjackson@dtm.ciw.edu -- http://www.astrojack.com
For further information contact PALS coordinator Dr. Michael Kelley at msk@astro.umd.edu or 301-405-3796.
SPECIAL ACCOMMODATIONS:Special accommodations for individuals with disabilities can be made by calling (301) 405-3001. It would be appreciated if we are notified at least one week in advance.
