We report the discovery of a Neptune-size planet (Rp = 3.0 Re) in the Hyades Cluster. The host star is in a binary system, comprising a K5V star and M7/8V star with a projected separation of 40 AU. The planet orbits the primary star with an orbital period of 17.3 days and a transit duration of 3 hours. The host star is bright (V=11.2, J=9.1) and so may be a good target for precise radial velocity measurements. K2-136A c is the first Neptune-sized planet to be found orbiting in a binary system within an open cluster. The Hyades is the nearest star cluster to the Sun, has an age of 625-750 Myr, and forms one of the fundamental rungs in the distance ladder; understanding the planet population in such a well-studied cluster can help us understand and set constraints on the formation and evolution of planetary systems.
@article{arxiv.1709.10398,
title = {K2-136: A Hyades Binary Star with a Neptune-sized Planet},
author = {David R. Ciardi and Ian J. M. Crossfield and Adina D. Feinstein and Joshua E. Schlieder and Erik A. Petigura and Trevor J. David and Makennah Bristow and Rahul I. Patel and Lauren Arnold and Björn Benneke and Jessie L. Christiansen and Courtney D. Dressing and Benjamin J. Fulton and Andrew W. Howard and Howard Isaacson and Evan Sinukoff and Beverly Thackeray},
journal= {arXiv preprint arXiv:1709.10398},
year = {2018}
}
Comments
13 pages, 8 figures, 2 tables. Accepted to AAS Journals