A 2014 study of the eclipsing binary star 1SWASPJ011351.29+314909.7 ( J0113+31 ) reported an unexpectedly high effective temperature for the M-dwarf companion to the 0.95-M _ { \odot } primary star .
The effective temperature inferred from the secondary eclipse depth was \sim 600 K higher than the value predicted from stellar models .
Such an anomalous result questions our understanding of low-mass stars and might indicate a significant uncertainty when inferring properties of exoplanets orbiting them .
We seek to measure the effective temperature of the M-dwarf companion using the light curve of J0113+31 recently observed by the Transiting Exoplanet Survey Satellite ( TESS ) .
We use the pycheops modelling software to fit a combined transit and eclipse model to the TESS light curve .
To calculate the secondary effective temperature , we compare the best-fit eclipse depth to the predicted eclipse depths from theoretical stellar models .
We determined the effective temperature of the M dwarf to be { T } _ { eff, 2 } = 3208 \pm 43 K , assuming \log g _ { 2 } = 5 , [ Fe/H ] = -0.4 and no alpha-element enhancement .
Varying these assumptions changes { T } _ { eff, 2 } by less than 100 K. These results do not support a large anomaly between observed and theoretical low-mass star temperatures .