Abstract

The Transiting Exoplanet Survey Satellite has produced a large number of single-Transit event candidates which are being monitored by the Next Generation Transit Survey (NGTS). We observed a second epoch for the TIC-231005575 system (Tmag = 12.06 and $T_{\rm eff} = 5500 \pm 85\, \mathrm{ K}$) with NGTS and a third epoch with Las Cumbres Observatory's telescope in South Africa to constrain the orbital period ($P = 61.777\, \mathrm{ d}$). Subsequent radial velocity measurements with CORALIE revealed the transiting object has a mass of M2 = 0.128 ± 0.003 M⊠, indicating the system is a G-M binary. The radius of the secondary is R2 = 0.154 ± 0.008 R⊠and is consistent with mesa models of stellar evolution to better than 1σ.