Three Unexpected Results from the Kepler Mission

Saul Rappaport ( M.I.T. )

The Kepler exoplanet finding mission monitored the visible flux of 200,000 stars in the constellation Cygnus nearly continuously for four years. The photometric precision of each flux measurement was as good as 100 parts per million (ppm), and the amplitudes of periodic features could be measured down to levels of a few ppm. With this unprecedented astronomical photometric precision, many new stellar and planetary discoveries have been made, including the detection of some 4000 exoplanets, a substantial fraction of which are in multi-planet systems. In this talk I review some of the general exoplanet discoveries, and then go on to discuss in some detail three areas where there have been unexpected discoveries. These include (i) 100 planets with incredibly tight orbits about their host star with periods of less than 1 day; (ii) four planets that appear to be disintegrating via the emission of dusty effluents; and (iii) 220 triple star systems discovered among the Kepler eclipsing binaries by eclipse timing variations induced by both light-travel-time delays and physical effects due to the proximity of the third body. None of these was among the main goals of the Kepler mission, but are some of the many unexpected discoveries made with Kepler.