Title: A Population of Very-Hot Super-Earths in Multiple-Planet Systems Should be Uncovered by Kepler Authors: Kevin C. Schlaufman, D.N.C. Lin, S. Ida
We simulate a Kepler-like observation of a theoretical exoplanet population and we show that the observed orbital period distribution of the Kepler giant planet candidates is best matched by an average stellar specific dissipation function Q_* in the interval 10^6 ~< Q_* ~< 10^7. In that situation, the few super-Earths that are driven to orbital periods P < 1 day by dynamical interactions in multiple-planet systems will survive tidal disruption for a significant fraction of the main-sequence lifetimes of their stellar hosts. Consequently, though these very-hot super-Earths are not characteristic of the overall super-Earth population, their substantial transit probability implies that they should be significant contributors to the full super-Earth population uncovered by Kepler. As a result, the CoRoT-7 system may be the first representative of a population of very-hot super-Earths that we suggest should be found in multiple-planet systems preferentially orbiting the least-dissipative stellar hosts in the Kepler sample.
Astronomers have discovered hundreds of Jupiter-like planets in our galaxy. However, a handful of the planets found orbiting distant stars are more Earth-sized. This gives hope to astrobiologists, who think we are more likely to find life on rocky planets with liquid water. The rocky planets found so far are actually more massive than our own. Dimitar Sasselov, professor of astronomy at Harvard University, coined the term "Super-Earths" to reflect their mass rather than any superior qualities. But Sasselov says that these planets - which range from about 2 to 10 Earth masses - could be superior to the Earth when it comes to sustaining life.