A long period (P=61.8 d M5V dwarf eclipsing a Sun-like star from TESS and NGTS

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 (T rig = 12.06 and Tat- = 5500 85 K) with NGTS and a third epoch with Las Cumbres Observatory's telescope in South Africa to constrain the orbital period (P = 61:77771d). Subsequent radial velocity measurements with CO LIE revealed the transiting object has a mass of M2 = 0.128 0.003 Mn, indicating the system is a G -M binary. The radius of the secondary is R2 = 0.154 0.008 Re and is consistent with MESA models of stellar evolution to better thari la.