The EBLM project – IX. Five fully convective M-dwarfs, precisely measured with CHEOPS and TESS light curves

Journal Article · Mon Sep 12 00:00:00 EDT 2022 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/stac2565· OSTI ID:1908390

Sebastian, D. ; Swayne, M. I. ; Maxted, P. F. L. ; Triaud, A. H. M. J. ; Sousa, S. G. ; Olofsson, G. ; Beck, M. ; Billot, N. ; Hoyer, S. ; Gill, S.; Heidari, N.; Martin, D. V. ; Persson, C. M.; Standing, M. R. ; Alibert, Y. ; Alonso, R. ; Anglada, G. ; Asquier, J.; Bárczy, T. ; Barrado, D. ; Barros, S. C. C. ; Battley, M. P. ; Baumjohann, W. ; Beck, T.; Benz, W. ; Bergomi, M.; Boisse, I.; Bonfils, X. ; Brandeker, A. ; Broeg, C. ; Cabrera, J.; Charnoz, S. ; Collier Cameron, A. ; Csizmadia, Sz ; Davies, M. B. ; Deleuil, M. ; Delrez, L. ; Demangeon, O. D. S. ; Demory, B-O ; Dransfield, G. ; Ehrenreich, D. ; Erikson, A.; Fortier, A. ; Fossati, L. ; Fridlund, M. ; Gandolfi, D. ; Gillon, M. ; Güdel, M.; Hasiba, J.; Hébrard, G.; Heng, K. ; Isaak, K. G. ; Kiss, L. L.; Kopp, E.; Kunovac, V. ; Laskar, J. ; Lecavelier des Etangs, A. ; Lendl, M. ; Lovis, C. ; Magrin, D. ; McCormac, J.; Miller, N. J. ; Nascimbeni, V. ; Ottensamer, R. ; Pagano, I. ; Pallé, E. ; Pepe, F. A.; Peter, G. ; Piotto, G. ; Pollacco, D.; Queloz, D. ; Ragazzoni, R. ; Rando, N.; Rauer, H. ; Ribas, I. ; Lalitha, S. ; Santerne, A. ; Santos, N. C. ; Scandariato, G. ; Ségransan, D. ; Simon, A. E. ; Smith, A. M. S. ; Steller, M. ; Szabó, Gy M.; Thomas, N.; Udry, S. ; Van Grootel, V. ; Walton, N. A.

ABSTRACT Eclipsing binaries are important benchmark objects to test and calibrate stellar structure and evolution models. This is especially true for binaries with a fully convective M-dwarf component for which direct measurements of these stars’ masses and radii are difficult using other techniques. Within the potential of M-dwarfs to be exoplanet host stars, the accuracy of theoretical predictions of their radius and effective temperature as a function of their mass is an active topic of discussion. Not only the parameters of transiting exoplanets but also the success of future atmospheric characterization relies on accurate theoretical predictions. We present the analysis of five eclipsing binaries with low-mass stellar companions out of a subsample of 23, for which we obtained ultra-high-precision light curves using the CHEOPS satellite. The observation of their primary and secondary eclipses are combined with spectroscopic measurements to precisely model the primary parameters and derive the M-dwarfs mass, radius, surface gravity, and effective temperature estimates using the PYCHEOPS data analysis software. Combining these results to the same set of parameters derived from TESS light curves, we find very good agreement (better than 1 per cent for radius and better than 0.2 per cent for surface gravity). We also analyse the importance of precise orbits from radial velocity measurements and find them to be crucial to derive M-dwarf radii in a regime below 5 per cent accuracy. These results add five valuable data points to the mass–radius diagram of fully convective M-dwarfs.

• Sponsoring Organization: USDOE Office of Nuclear Energy (NE), Nuclear Fuel Cycle and Supply Chain
• Grant/Contract Number: CEECIND/00826/2018; IF/01312/2014/CP1215/CT0004
• OSTI ID: 1908390
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Vol. 519 Journal Issue: 3; ISSN 0035-8711
• Publisher: Oxford University Press
• Country of Publication: United Kingdom
• Language: English