Characterizing the cool KOIs. VI. H-and K-band spectra of Kepler M dwarf planet-candidate hosts

Philip S. Muirhead, Juliette Becker, Gregory A. Feiden, Bárbara Rojas-Ayala, Andrew Vanderburg, Ellen M. Price, Rachel Thorp, Nicholas M. Law, Reed Riddle, Christoph Baranec, Katherine Hamren, Everett Schlawin, Kevin R. Covey, John Asher Johnson, James P. Lloyd

Research output: Contribution to journalArticlepeer-review

55 Scopus citations


We present H- and K-band spectra for late-type Kepler Objects of Interest (the "Cool KOIs"): low-mass stars with transiting-planet candidates discovered by NASA's Kepler Mission that are listed on the NASA Exoplanet Archive. We acquired spectra of 103 Cool KOIs and used the indices and calibrations of Rojas-Ayala et al. to determine their spectral types, stellar effective temperatures, and metallicities, significantly augmenting previously published values. We interpolate our measured effective temperatures and metallicities onto evolutionary isochrones to determine stellar masses, radii, luminosities, and distances, assuming the stars have settled onto the main sequence. As a choice of isochrones, we use a new suite of Dartmouth predictions that reliably include mid-to-late M dwarf stars. We identify five M4V stars: KOI-961 (confirmed as Kepler 42), KOI-2704, KOI-2842, KOI-4290, and the secondary component to visual binary KOI-1725, which we call KOI-1725 B. We also identify a peculiar star, KOI-3497, which has Na and Ca lines consistent with a dwarf star but CO lines consistent with a giant. Visible-wavelength adaptive optics imaging reveals two objects within a 1 arcsec diameter; however, the objects' colors are peculiar. The spectra and properties presented in this paper serve as a resource for prioritizing follow-up observations and planet validation efforts for the Cool KOIs and are all available for download online using the "data behind the figure" feature.

Original languageEnglish (US)
Article number5
JournalAstrophysical Journal, Supplement Series
Issue number1
StatePublished - Jul 1 2014
Externally publishedYes


  • binaries: eclipsing
  • binaries: visual
  • planetary systems
  • stars: abundances
  • stars: fundamental parameters
  • stars: individual (KOI-2704, KOI-2842, KOI-4290, KOI-1725, KOI-3497)
  • stars: late-type
  • stars: low-mass

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'Characterizing the cool KOIs. VI. H-and K-band spectra of Kepler M dwarf planet-candidate hosts'. Together they form a unique fingerprint.

Cite this