Kepler-432 b: a massive planet in a highly eccentric orbit transiting a red giant

Ciceri, S.; Lillo-Box, J.; Southworth, J.; Mancini, L.; Th. Henning; Barrado, D.

Abstract

We report the first disclosure of the planetary nature of Kepler-432?b (aka Kepler object of interest KOI-1299.01). We accurately constrained its mass and eccentricity by high-precision radial velocity measurements obtained with the CAFE spectrograph at the CAHA 2.2-m telescope. By simultaneously fitting these new data and Kepler photometry, we found that Kepler-432?b is a dense transiting exoplanet with a mass of Mp = 4.87 ± 0.48MJup and radius of Rp = 1.120 ± 0.036RJup. The planet revolves every 52.5?d around a K giant star that ascends the red giant branch, and it moves on a highly eccentric orbit with e = 0.535 ± 0.030. By analysing two near-IR high-resolution images, we found that a star is located at 1.1'' from Kepler-432, but it is too faint to cause significant effects on the transit depth. Together with Kepler-56 and Kepler-91, Kepler-432 occupies an almost-desert region of parameter space, which is important for constraining the evolutionary processes of planetary systems.

• Journal Article Type: Article
• Acceptance Date: Nov 28, 2014
• Online Publication Date: Dec 22, 2014
• Publication Date: 2015-01
• Journal: ASTRONOMY & ASTROPHYSICS
• Print ISSN: 0004-6361
• Electronic ISSN: 1432-0746
• Publisher: EDP Sciences
• Peer Reviewed: Peer Reviewed
• Volume: 573
• Article Number: L5
• DOI: https://doi.org/10.1051/0004-6361/201425145
• Keywords: planetary systems, stars: fundamental parameters, stars: individual: Kepler-432
• Publisher URL: https://doi.org/10.1051/0004-6361/201425145