The closest extremely low-mass white dwarf to the Sun

We present the orbit and properties of 2MASS J050051.85-093054.9, establishing it as the closest (d approximate to 71 pc) extremely low-mass white dwarf to the Sun. We find that this star is hydrogen rich with T-eff approximate to 10 500 K, log g approximate to 5.9, and, following evolutionary models, has a mass of approximate to 0.17 M-circle dot. Independent analysis of radial velocity and Transiting Exoplanet Survey Satellite (TESS) photometric time series reveals an orbital period of approximate to 9.5 h. Its high velocity amplitude (K approximate to 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.