Discovery of a possible Earth-sized planet

Posted on August 29, 2010 by


The journal Science reports the following in the article  Kepler-9: A System of Multiple Planets Transiting a Sun-Like Star, Confirmed by Timing Variations — Holman et al., 10.1126/science.1195778 — Science:

The Kepler spacecraft is monitoring over 150,000 stars for evidence of planets transiting those stars. We report the detection, based on 7 months of Kepler observations, of two Saturn-size planets that transit the same Sun-like star. Their 19.2- and 38.9-day periods are presently increasing and decreasing at respective average rates of 4 and 39 min per orbit, and in addition the transit times of the inner body display an alternating variation of smaller amplitude. These signatures are characteristic of gravitational interaction of two planets near a 2:1 orbital resonance. Six radial velocity observations show that these two planets are the most massive objects orbiting close to the star and substantially improve the estimates of their masses. After removing the signal of the two conrmed giant planets, we identify an additional transiting super-Earth-size planet candidate with a period of 1.6 days.

Posted in: Astronomy