Speaker:
Eric Agol
Speaker Link:
Date:
Thursday, January 23, 2014
Time:
3:30 pm
Location:
RH 101
ABSTRACT:
When a planet orbits a star, and the orbit is viewed edge-on, a slightly dimming can be seen as the planet passes in front of (transits) the star every orbital period; to date NASA's Kepler spacecraft has found thousands of transiting planets, with about 30% that show multiple ransiting planets. Dynamical interactions between multiple planets can lead to detectable variations in the times of transit, giving a means to constrain the masses and eccentricities of the planets. I will give an introduction to the theory of transit-timing variations (TTV), how this phenomenon can be used to detect and confirm planets, how it can make planet transit detection difficult, and how a new approach to detecting planets can turn up candidates that are missed by the Kepler software.
I will give examples of systems that display strong transit-timing variations and how these have been used to characterize these planets. I will conclude with the recent detection with Kepler of two small planets, one only 40% larger in diameter than Earth, which orbit the same star in the so-called 'Habitable zone,' where there may be the potential for surface liquid water
Host:
Aaron Barth