The EBLM Project - XIX. The absence of radius inflation in a homogeneous analysis of 66 Northern low-mass eclipsing binaries

@misc{davis2026eblm,
  title = {{The EBLM Project - XIX. The absence of radius inflation in a homogeneous analysis of 66 Northern low-mass eclipsing binaries}},
  author = {Yasmin T. Davis and Amaury H. M. J. Triaud and David V. Martin and Alix V. Freckelton and Jenni R. French and Adam T. Stevenson and Annelies Mortier and Karen Collins and Pierre F. L. Maxted and Daniel Sebastian and Aleyna Adamson and Thomas A. Baycroft and Isabelle Boisse and Gavin A. L. Coleman and Georgina Dransfield and Yilen Gómez Maqueo Chew and Leslie Hebb and Neda Heidari and Vedad Kunovac and James McCormac and Nikki J. Miller and Richard Nelson and Martin Nielsen and Alexandre Santerne and Madison G. Scott and Owen Scutt and Alexis M. S. Smith and Matthew R. Standing and Amalie Stokholm and Matthew I. Swayne and Mathilde Timmermans and Peter J. Wheatley and Emma Willett},
  howpublished = {arXiv},
  year = {2026},
  month = oct,
  doi = {10.48550/arxiv.2610.18338},
  eprint = {2610.18338},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2610.18338},
}

TY  - UNPB
TI  - The EBLM Project - XIX. The absence of radius inflation in a homogeneous analysis of 66 Northern low-mass eclipsing binaries
AU  - Yasmin T. Davis
AU  - Amaury H. M. J. Triaud
AU  - David V. Martin
AU  - Alix V. Freckelton
AU  - Jenni R. French
AU  - Adam T. Stevenson
AU  - Annelies Mortier
AU  - Karen Collins
AU  - Pierre F. L. Maxted
AU  - Daniel Sebastian
AU  - Aleyna Adamson
AU  - Thomas A. Baycroft
AU  - Isabelle Boisse
AU  - Gavin A. L. Coleman
AU  - Georgina Dransfield
AU  - Yilen Gómez Maqueo Chew
AU  - Leslie Hebb
AU  - Neda Heidari
AU  - Vedad Kunovac
AU  - James McCormac
AU  - Nikki J. Miller
AU  - Richard Nelson
AU  - Martin Nielsen
AU  - Alexandre Santerne
AU  - Madison G. Scott
AU  - Owen Scutt
AU  - Alexis M. S. Smith
AU  - Matthew R. Standing
AU  - Amalie Stokholm
AU  - Matthew I. Swayne
AU  - Mathilde Timmermans
AU  - Peter J. Wheatley
AU  - Emma Willett
PY  - 2026
DA  - 2026/10/13
PB  - arXiv
DO  - 10.48550/arxiv.2610.18338
UR  - https://arxiv.org/abs/2610.18338
AB  - Precise and accurate measurements of host stars are crucial in the search for Earth-like exoplanets, and M-dwarfs are favourable targets in this quest. Low-mass eclipsing binaries offer unique opportunities to empirically determine stellar masses and radii for low-mass stars where stellar models may be systematically biased. We present results from the EBLM-North sample, the largest homogeneous study of low-mass eclipsing binaries with secondary characterisation yet, combining high-resolution and high-precision radial velocities from SOPHIE and TESS photometry. We measure a median precision for stellar companions of 4.2% in radius and 8.6% in mass within a sub-sample of 50 high-quality binaries, all with orbital periods P_bin > 5 days. We compare our data to the Baraffe and MIST isochrones, and find our sample is statistically consistent with those models, producing reduced chi-squared values, χ^2_ν∼ 1. Our measured radius inflation is 0.3± 1.6% indicating no statistically significant trend. We likewise detect no significant trend with metallicity, despite having the precision to identify such a relationship. As such, our observations do not appear to follow the general metallicity trend predicted in MIST. A χ_ν^2 ∼ 1 indicates the scatter in our results is commensurate with our uncertainties alone. These results constrain the scope for unmodelled effects on the mass-radius relation that would produce radius deviations greater than 4.2%. However, our secondary effective temperatures do not reproduce this high level of agreement with the models, and we do not recover the predicted trends with metallicity.
ER  -