Three Small Planets Transiting a Hyades Star

Summary, in English

We present the discovery of three small planets transiting K2-136 (LP 358 348, EPIC 247589423), a late K dwarf in the Hyades. The planets have orbital periods of 7.9757 ± 0.0011, 17.30681_-0.00036^+0.00034, and 25.5715_-0.0040^+0.0038 days, and radii of 1.05 ± 0.16, 3.14 ± 0.36, and 1.55_-0.21^+0.24 R_⊕, respectively. With an age of 600-800 Myr, these planets are some of the smallest and youngest transiting planets known. Due to the relatively bright (J = 9.1) host star, the planets are compelling targets for future characterization via radial velocity mass measurements and transmission spectroscopy. As the first known star with multiple transiting planets in a cluster, the system should be helpful for testing theories of planet formation and migration.

• Author: John H. Livingston; Fei Dai; Teruyuki Hirano; Davide Gandolfi; Grzegorz Nowak; Michael Endl; Sergio Velasco; Akihiko Fukui; Norio Narita; Jorge Prieto-Arranz; Oscar Barragan; Felice Cusano; Simon Albrecht; Juan Cabrera; William D. Cochran; Szilard Csizmadia; Hans J. Deeg; Philipp Eigmüller; Anders Erikson; Malcolm Fridlund; Sascha Grziwa; Eike W. Guenther; Artie P. Hatzes; Kiyoe Kawauchi; Judith Korth; David Nespral; Enric Palle; Martin Pätzold; Carina M. Persson; Heike Rauer; Alexis M.S. Smith; Motohide Tamura; Yusuke Tanaka; Vincent Van Eylen; Noriharu Watanabe; Joshua N. Winn
• Publishing year: 2018-03
• Language: English
• Publication/Series: Astronomical Journal
• Volume: 155
• Issue: 3
• Links: http://dx.doi.org/10.3847/1538-3881/aaa841
• Document type: Journal article
• Publisher: IOP Publishing
• Keywords: planetary systems; planets and satellites: detection; stars: individual (LP 358-348); techniques: photometric; techniques: spectroscopic
• Status: Published
• ISBN/ISSN/Other: ISSN: 0004-6256