Characterizing K2 Planet Discoveries: A super-Earth transiting the bright K-dwarf HIP 116454
- Author(s)
- Andrew Vanderburg, Benjamin T. Montet, John Asher Johnson, L. A. Buchhave, Li Zeng, Rainer Kuschnig, Werner Wolfgang Weiss
- 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] = -0.16 ± 0.08 and has a radius R∗= 0.716 ± 0.024 R
⊙ and mass M∗= 0.775 ± 0.027 M
⊙. The star was observed by the Kepler spacecraft during its Two-Wheeled Concept Engineering Test in 2014 February. 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 R
p = 2.53 ± 0.18 R
⊕. Radial velocity observations with the HARPS-N spectrograph reveal a 11.82 ± 1.33 M
⊕ 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.
- Organisation(s)
- Department of Astrophysics
- External organisation(s)
- Harvard-Smithsonian Center for Astrophysics, National Science Foundation, California Institute of Technology (Caltech), Natural History Museum of Denmark
- Journal
- The Astrophysical Journal
- Volume
- 800
- ISSN
- 0004-637X
- DOI
- https://doi.org/10.1088/0004-637X/800/1/59
- Publication date
- 2015
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103003 Astronomy, 103004 Astrophysics
- Keywords
- ASJC Scopus subject areas
- Astronomy and Astrophysics, Space and Planetary Science
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/characterizing-k2-planet-discoveries-a-superearth-transiting-the-bright-kdwarf-hip-116454(2f499565-01ee-44c3-b0c7-f12006c2bed1).html