And you thought Warm Jupiters were lonely

| Updated: Jul 15, 2016 13:21 IST

Washington D.C, Jul 15 (ANI): Turns out, Warm Jupiters are not as lonely as we expected. After analyzing four years of Kepler space telescope observations, the University of Toronto astronomers showed that many in this class of exoplanets have unexpected planetary companions. The team's analysis provided strong evidence of the existence of two distinct types of Warm Jupiters, each with their own formation and dynamical history. The two types include those that have companions and thus, likely formed where we find them today; and those with no companions that likely migrated to their current positions. According to lead-author Chelsea Huang, "Our findings suggest that a big fraction of Warm Jupiters cannot have migrated to their current positions dynamically and that it would be a good idea to consider more seriously that they formed where we find them." Unlike the Sun's family of giant planets, Warm Jupiters orbit their parent stars at roughly the same distance that Mercury, Venus and the Earth circle the Sun. Because of their proximity to their parent stars, they are warmer than our system's cold gas giants, though not as hot as Hot Jupiters, which are typically closer to their parent stars than Mercury. It has generally been thought that Warm Jupiters didn't form where we find them today; they are too close to their parent stars to have accumulated large, gas-giant-like atmospheres. So, it appeared likely that they formed in the outer reaches of their planetary systems and migrated inward to their current positions, and might in fact continue their inward journey to become Hot Jupiters. On such a migration, the gravity of any Warm Jupiter would have disturbed neighbouring or companion planets, ejecting them from the system. But, instead of finding "lonely," companion-less Warm Jupiters, the team found that 11 of the 27 targets they studied have companions ranging in size from Earth-like to Neptune-like. "And when we take into account that there is more analysis to come," noted Huang, "the number of Warm Jupiters with smaller neighbours may be even higher. We may find that more than half have companions." The study is published in the Astrophysical Journal. (ANI)