Characterizing K2 Planet Discoveries: A super-Earth transiting the bright K-dwarf HIP 116454

Andrew Vanderburg, Benjamin T. Montet, John Asher Johnson, Lars A. Buchhave, Li Zeng, Francesco Pepe, Andrew Collier Cameron, David W. Latham, Emilio Molinari, Stephane Udry, Christophe Lovis, Jaymie M. Matthews, Chris Cameron, Nicholas Law, Brendan P. Bowler, Ruth Angus, Christoph Baranec, Allyson Bieryla, Walter Boschin, David Charbonneau, Rosario Cosentino, Xavier Dumusque, Pedro Figueira, David B. Guenther, Avet Harutyunyan, Coel Hellier, Rainer Kuschnig, Mercedes Lopez-Morales, Michel Mayor, Giusi Micela, Anthony F. J. Moffat, Marco Pedani, David F. Phillips, Giampaolo Piotto, Don Pollacco, Didier Queloz, Ken Rice, Reed Riddle, Jason F. Rowe, Slavek M. Rucinski, Dimitar Sasselov, Damien Segransan, Alessandro Sozzetti, Andrew Szentgyorgyi, Chris Watson, Werner W. Weiss

(Submitted on 17 Dec 2014)

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.

Comments: 16 pages, 8 figures. Accepted by ApJ

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Solar and Stellar Astrophysics (astro-ph.SR)

Cite as: arXiv:1412.5674 [astro-ph.EP]

 (or arXiv:1412.5674v1 [astro-ph.EP] for this version)

Submission history

From: Andrew Vanderburg 

[v1] Wed, 17 Dec 2014 23:30:12 GMT (1368kb)

http://arxiv.org/abs/1412.5674

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