Characterizing K2 Planet Discoveries: A super-Earth transiting the bright K-dwarf HIP 116454
Abstract
We report the first planet discovery from the two-wheeled Kepler (K2) mission: HIP 116454 b. The host star HIP 116454 is a bright (V = 10.1, K = 8.0) K1-dwarf with high proper motion, and a parallax-based distance of 55.2 +/- 5.4 pc. Based on high-resolution optical spectroscopy, we find that the host star is metal-poor with [Fe/H] = -.16 +/- .18, and has a radius R = 0.716 +/- .0024 R_sun and mass M = .775 +/- .027 Msun. The star was observed by the Kepler spacecraft during its Two-Wheeled Concept Engineering Test in February 2014. During the 9 days of observations, K2 observed a single transit event. Using a new K2 photometric analysis technique we are able to correct small telescope drifts and recover the observed transit at high confidence, corresponding to a planetary radius of Rp = 2.53 +/- 0.18 Rearth. Radial velocity observations with the HARPS-N spectrograph reveal a 11.82 +/- 1.33 Mearth planet in a 9.1 day orbit, consistent with the transit depth, duration, and ephemeris. Follow-up photometric measurements from the MOST satellite confirm the transit observed in the K2 photometry and provide a refined ephemeris, making HIP 116454 b amenable for future follow-up observations of this latest addition to the growing population of transiting super-Earths around nearby, bright stars.
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Cite
@article{arxiv.1412.5674,
title = {Characterizing K2 Planet Discoveries: A super-Earth transiting the bright K-dwarf HIP 116454},
author = {Andrew Vanderburg and Benjamin T. Montet and John Asher Johnson and Lars A. Buchhave and Li Zeng and Francesco Pepe and Andrew Collier Cameron and David W. Latham and Emilio Molinari and Stephane Udry and Christophe Lovis and Jaymie M. Matthews and Chris Cameron and Nicholas Law and Brendan P. Bowler and Ruth Angus and Christoph Baranec and Allyson Bieryla and Walter Boschin and David Charbonneau and Rosario Cosentino and Xavier Dumusque and Pedro Figueira and David B. Guenther and Avet Harutyunyan and Coel Hellier and Rainer Kuschnig and Mercedes Lopez-Morales and Michel Mayor and Giusi Micela and Anthony F. J. Moffat and Marco Pedani and David F. Phillips and Giampaolo Piotto and Don Pollacco and Didier Queloz and Ken Rice and Reed Riddle and Jason F. Rowe and Slavek M. Rucinski and Dimitar Sasselov and Damien Segransan and Alessandro Sozzetti and Andrew Szentgyorgyi and Chris Watson and Werner W. Weiss},
journal= {arXiv preprint arXiv:1412.5674},
year = {2015}
}
Comments
16 pages, 8 figures. Accepted by ApJ