NOAO >   Observing Info >   Approved Programs >   2018A-0354

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Program Information for 2018A-0354


PI: Eunkyu Han, Boston U., eunkyuh@bu.edu
Address: 725 COMMONWEALTH AVENUE, BOSTON, MA 02215 U.S.A

CoI: Philip Muirhead, Boston U.
CoI: Gregory Mace, U. of Texas, Austin

Title: Fundamental properties of low-mass stars: determination of a self-consistent mass-radius-luminosity relationship

Abstract: M dwarf stars are low-mass and cool main sequence stars; their masses range from 0.08 to 0.6 solar mass and effective temperatures range from 2300K to 3800K. M dwarf stars make up over 70% of stars by number [Bochanski et al. 2010] and are known to host at least two exoplanets on average [Gaidos et al. 2014]. NASA’s future Transiting Exoplanet Survey Satellite [TESS, projected launch March 2018, Ricker et al. 2010] mission is expected to discover hundreds of terrestrial exoplanets orbiting M dwarfs [Sullivan et al. 2015], which will be nearby and amenable for detailed characterization. To accurately measure radii and equilibrium temperatures of these exoplanets and determine if they are in the habitable zone, we need to know the host star properties, specifically mass, radius and effective temperature, to equal accuracy. However, we do not have self-consistently determined relationship between M dwarf stellar properties; the mass-luminosity relationship from resolved binaries cannot measure radii and the radius luminosity relationship from interferometric observations cannot measure the masses. The best way to determine relationships for M dwarf stars is to study tidally-locked, noninteracting, and mutually eclipsing binaries [EBs]; by combining their photometric and spectroscopic data, we can empirically determine the physical parameters of stars without relying on the stellar evolutionary models. We propose to measure the radial velocities [RVs] of individual component stars of knwon EBs that lack SB2 RV measurements and determine the mass of each component, using the IGRINS infrared spectra. Infrared spectra allow us to measure both components RV where optical does not. Ultimately, We will combine the measurements to determine the mass-radius-luminosity relationship for M dwarf stars, which is critical for choosing the best TESS M dwarf exoplanets for detailed characterization and follow-up ground based observations.

Program Type: Standard/Galactic

Scheduled Nights:
Run 1 (2018A):  GEM-SQ/IGRINS -- 16hrs band 1 (GS-2018A-Q-124 )


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NOAO >   Observing Info >   Approved Programs >   2018A-0354

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