Thursday, May 19, 2016

Two Giant Planets on Very Dissimilar Orbits

Raetz et al. (2016) present the first ever detection of a directly imaged planet in a wide-separation orbit around a star that also hosts a short-period transiting planet candidate. The directly imaged planet is identified as CVSO 30c and the short-period transiting planet candidate is identified as CVSO 30b. Both CVSO 30b and CVSO 30c are gas giant planets, each estimated to contain a few times the mass of Jupiter. The host star of CVSO 30b and CVSO 30c is a relatively young star estimated to be only a couple or so million years old. Its effective surface temperature is ~3470 K, its mass is 0.34 to 0.44 times the Sun's mass and its luminosity is about a quarter the Sun's luminosity.

CVSO 30b is short-period transiting planet candidate with an extremely short orbital period of only 10.8 hours. In contrast, the directly imaged planet CVSO 30c has an orbital period of about 27,000 years. The orbits of both planets could not have been more different. Both planets may have gotten into their current orbits following a violent planet-planet scattering event. CVSO 30c is 662 ± 96 AU from its host star, and this is far enough that the planet is not lost in the glare of its host star, allowing it to be directly detected. The direct observations indicate that the equilibrium temperature of CVSO 30c is ~1600 K.

Raetz et al. (2016), "YETI observations of the young transiting planet candidate CVSO 30 b", arXiv:1605.05091 [astro-ph.EP]