The EBLM project -- IX. Five fully convective M-dwarfs, precisely measured with CHEOPS and TESS light curves
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 characterisation rely on accurate theoretical predictions. We present the analysis of five eclipsing binaries with low-mass stellar companions out of a sub-sample 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\% for radius and better than 0.2% 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% accuracy. These results add five valuable data points to the mass-radius diagram of fully-convective M-dwarfs.
Keywords
Cite
@article{arxiv.2209.03128,
title = {The EBLM project -- IX. Five fully convective M-dwarfs, precisely measured with CHEOPS and TESS light curves},
author = {D. Sebastian and M. I. Swayne and P. F. L. Maxted and A. H. M. J. Triaud and S. G. Sousa and G. Olofsson and M. Beck and N. Billot and S. Hoyer and S. Gill and N. Heidari and D. V. Martin and C. M. Persson and M. R. Standing and Y. Alibert and R. Alonso and G. Anglada and J. Asquier and T. Bárczy and D. Barrado and S. C. C. Barros and M. P. Battley and W. Baumjohann and T. Beck and W. Benz and M. Bergomi and I. Boisse and X. Bonfils and A. Brandeker and C. Broeg and J. Cabrera and S. Charnoz and A. Collier Cameron and Sz. Csizmadia and M. B. Davies and M. Deleuil and L. Delrez and O. D. S. Demangeon and B. -O. Demory and G. Dransfield and D. Ehrenreich and A. Erikson and A. Fortier and L. Fossati and M. Fridlund and D. Gandolfi and M. Gillon and M. Güdel and J. Hasiba and G. Hébrard and K. Heng and K. G. Isaak and L. L. Kiss and E. Kopp and V. Kunovac and J. Laskar and A. Lecavelier des Etangs and M. Lendl and C. Lovis and D. Magrin and J. McCormac and N. J. Miller and V. Nascimbeni and R. Ottensamer and I. Pagano and E. Pallé and F. A. Pepe and G. Peter and G. Piotto and D. Pollacco and D. Queloz and R. Ragazzoni and N. Rando and H. Rauer and I. Ribas and S. Lalitha and A. Santerne and N. C. Santos and G. Scandariato and D. Ségransan and A. E. Simon and A. M. S. Smith and M. Steller and Gy. M. Szabó and N. Thomas and S. Udry and V. Van Grootel and N. A. Walton},
journal= {arXiv preprint arXiv:2209.03128},
year = {2022}
}
Comments
19 pages, 12 figures, accepted for publication in MNRAS