Kawka, AdelaSimpson, Jeffrey DVennes, StephaneBessell, MikeDa Costa, GaryMarino, A FMurphy, Simon J.2022-07-142022-07-140035-8711http://hdl.handle.net/1885/268855We present the orbit and properties of 2MASS J050051.85−093054.9, establishing it as the closest (d ≈ 71 pc) extremely low-mass white dwarf to the Sun. We find that this star is hydrogen rich with Teff ≈ 10 500 K, log g ≈ 5.9, and, following evolutionary models, has a mass of ≈0.17 M. Independent analysis of radial velocity and Transiting Exoplanet Survey Satellite (TESS) photometric time series reveals an orbital period of ≈9.5 h. Its high velocity amplitude (K ≈ 144 km s−1) produces a measurable Doppler beaming effect in the TESS light curve with an amplitude of 1 mmag. The unseen companion is most likely a faint white dwarf. J0500−0930 belongs to a class of post-common envelope systems that will most likely merge through unstable mass transfer and in specific circumstances lead to Type Ia supernova explosions.AFM received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement 797100application/pdfen-AU© 2020 The authorsbinariesclose – starsindividualwhite dwarfs.202010.1093/mnrasl/slaa0682021-08-01