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 CharbonneauRosario 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

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

68 Citations (Scopus)

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-star = 0.716 +/- 0.024 R-circle dot and mass M-star = 0.775 +/- 0.027M(circle dot). 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-circle plus. Radial velocity observations with the HARPS-N spectrograph reveal a 11.82 +/- 1.33 M-circle plus 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.

Original languageEnglish
Article number59
Number of pages14
JournalAstrophysical Journal
Volume800
Issue number1
DOIs
Publication statusPublished - 10 Feb 2015

Keywords

  • planets and satellites: detection
  • techniques: photometric
  • LASER ADAPTIVE OPTICS
  • NEPTUNE-MASS PLANET
  • SKY SURVEY
  • PROPER-MOTION
  • SHORT-PERIOD
  • HD 97658B
  • EXOPLANET
  • KEPLER
  • STARS
  • MISSION

Cite this