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Characterizing K2 Candidate Planetary Systems Orbiting Low-Mass Stars. I. Classifying Low-Mass Host Stars Observed During Campaigns 1-7We present near-infrared spectra for 144 candidate planetary systems identified during Campaigns 1-7 of the NASA K2 Mission. The goal of the survey was to characterize planets orbiting low-mass stars, but our Infrared Telescope Facility/SpeX and Palomar/TripleSpec spectroscopic observations revealed that 49% of our targets were actually giant stars or hotter dwarfs reddened by interstellar extinction. For the 72 stars with spectra consistent with classification as cool dwarfs (spectral types K3-M4), we refined their stellar properties by applying empirical relations based on stars with interferometric radius measurements. Although our revised temperatures are generally consistent with those reported in the Ecliptic Plane Input Catalog (EPIC), our revised stellar radii are typically 0.13 solar radius (39%) larger than the EPIC values, which were based on model isochrones that have been shown to underestimate the radii of cool dwarfs. Our improved stellar characterizations will enable more efficient prioritization of K2 targets for follow-up studies.
Document ID
Document Type
Reprint (Version printed in journal)
Dressing, Courtney D. (California Inst. of Tech. Pasadena, CA, United States)
Newton, Elisabeth R. (Massachusetts Inst. of Tech. Cambridge, MA, United States)
Schlieder, Joshua E. (NASA Goddard Space Flight Center Greenbelt, MD United States)
Charbomeau, David (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Krutson, Heather A. (California Inst. of Tech. Pasadena, CA, United States)
Vanderburg, Andrew (Harvard-Smithsonian Center for Astrophysics Cambridge, MA, United States)
Sinukoff, Evan (Hawaii Univ. at Manoa Honolulu, HI, United States)
Date Acquired
August 17, 2017
Publication Date
February 17, 2017
Publication Information
Publication: The Astrophysical Journal
Volume: 836
Issue: 2
ISSN: 0004-637X
Subject Category
Report/Patent Number
Funding Number(s)
Distribution Limits
Campaigns17 of the NASA K2 Mission