Stellar and Planetary Parameters for K2's Late-type Dwarf Systems from C1 to C5

摘要: The NASA K2 mission uses photometry to find planets transiting stars of various types. M dwarfs are high interest since they host more short-period than any other type main-sequence star and around have deeper transits compared stars. In this paper, we present stellar parameters from K hosting planet candidates discovered by our team. Using the SOFI spectrograph on European Southern Observatory's New Technology Telescope, obtained R ≈ 1000 J-, H-, K-band (0.95–2.52 μm) spectra 34 late-type candidate systems 12 bright K4–M5 with interferometrically measured radii effective temperatures. Out targets, identify 27 these as dwarfs. We measure equivalent widths spectral features, derive calibration relations using interferometric measurements, estimate radii, temperatures, masses, luminosities for hosts. Our calibrations provide temperatures median uncertainties 0.059 R⊙ (16.09%) 160 (4.33%), respectively. then reassess equilibrium known based spectroscopically derived parameters. Since a planet's radius temperature depend its star, study provides precise planetary orbiting observed K2. an approximately 3 R⊕ 500 K, respectively, several (K2-18b K2-72e) receiving near-Earth-like levels incident irradiation.