Fundamental effective temperature measurements for eclipsing binary stars -- III. SPIRou near-infrared spectroscopy and CHEOPS photometry of the benchmark G0V star EBLM J0113+31

Abstract

EBLM J0113+31 is moderately bright (V=10.1), metal-poor ([Fe/H]$\approx -0.3$) G0V star with a much fainter M dwarf companion on a wide, eccentric orbit (=14.3 d). We have used near-infrared spectroscopy obtained with the SPIRou spectrograph to measure the semi-amplitude of the M dwarf's spectroscopic orbit, and high-precision photometry of the eclipse and transit from the CHEOPS and TESS space missions to measure the geometry of this binary system. From the combined analysis of these data together with previously published observations we obtain the following model-independent masses and radii: $M_1=1.029\pm 0.025M_{\odot }$, $M_2=0.197\pm 0.003M_{\odot }$, $R_1=1.417\pm 0.014R_{\odot }$, $R_2=0.215\pm 0.002R_{\odot }$. Using $R_1$ and the parallax from Gaia EDR3 we find that this star's angular diameter is $\theta =0.0745\pm 0.0007$ mas. The apparent bolometric flux of the G0V star corrected for both extinction and the contribution from the M dwarf ($<0.2$ per cent) is ${\mathcal{F}}_{\oplus ,0}=(2.62\pm 0.05)\times 10^{-9}$ erg.cm${}^{-2}$.s${}^{-1}$. Hence, this G0V star has an effective temperature $T_{\mathrm{eff},1}=6124\mathrm{K}\pm 40\mathrm{K}(rnd.)\pm 10\mathrm{K}(sys.)$. EBLM J0113+31 is an ideal benchmark star that can be used for "end-to-end" tests of the stellar parameters measured by large-scale spectroscopic surveys, or stellar parameters derived from asteroseismology with PLATO. The techniques developed here can be applied to many other eclipsing binaries in order to create a network of such benchmark stars.

Accepted for publication in MNRAS. 15 pages, 9 figures

References in corpus (20)

• The Gaia mission
• A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
• The Dartmouth Stellar Evolution Database
• New constraints on the chemical evolution of the solar neighbourhood and Galactic disc(s). Improved astrophysical parameters for the Geneva-Copenhagen Survey
• Determining stellar atmospheric parameters and chemical abundances of FGK stars with iSpec
• Modern stellar spectroscopy caveats
• SPIRou: nIR velocimetry & spectropolarimetry at the CFHT
• First Results from the CHARA Array. IV. The Interferometric Radii of Low-Mass Stars
• The Gaia FGK Benchmark Stars - High resolution spectral library
• The TESS-HERMES survey Data Release 1: high-resolution spectroscopy of the TESS southern continuous viewing zone
• SPECULOOS -- Ultracool Dwarf Transit Survey: Target List and Strategy
• The EBLM Project IV. Spectroscopic orbits of over 100 eclipsing M dwarfs masquerading as transiting hot-Jupiters
• The Compositional Diversity of Low-Mass Exoplanets
• The EBLM Project V. Physical properties of ten fully convective, very-low-mass stars
• The Gaia-ESO Survey: Target selection of open cluster stars
• The EBLM project. II. A very hot, low-mass M dwarf in an eccentric and long period eclipsing binary system from SuperWASP
• The EBLM Project VI. The mass and radius of five low-mass stars in F+M binaries discovered by the WASP survey
• The EBLM project -- VIII. First results for M-dwarf mass, radius and effective temperature measurements using CHEOPS light curves
• Revised age for CM Draconis and WD 1633+572: Toward a resolution of model-observation radius discrepancies
• The TESS light curve of the eccentric eclipsing binary 1SWASP J011351.29+314909.7 -- no evidence for a very hot M-dwarf companion