2024MNRAS.535.3343M

Well-characterized M-dwarfs are rare, particularly with respect to effective temperature. In this letter, we re-analyse two benchmark M-dwarfs in eclipsing binaries from Kepler/K2: KIC 1571511AB and HD 24465AB. Both have temperatures reported to be hotter or colder by $\approx 1000$ K in comparison with both models and the majority of other M-dwarfs in the literature. By modelling the secondary eclipses with both the original data and new data from TESS, we derive significantly different temperatures: $2865\pm 27$ for KIC 1571511B and $3081\pm 32$ for HD 24465B from the Transiting Exoplanet Survey Satellite (TESS) and $3114\pm 32$ K for HD 24465B from K2. These new temperatures are not outliers. Removing this discrepancy allows these M-dwarfs to be truly benchmarks. Our work also provides relief to stellar modellers. We encourage more measurements of M-dwarf effective temperatures with robust methods.