Muso

ZTF J153932.16+502738.8 is a double binary white dwarf with an orbital period of just 6.91 minutes. Its period has been observed to be decreasing, due to the emission of gravitational waves. It is both an eclipsing binary and a double-lined spectroscopic binary. The hotter white dwarf is 48,900 K, and the other one is significantly cooler (<10,000K). The stars may merge into one in 130,000 years, or if mass transfers between them, they may separate again. Their distance from Earth is estimated at 2.3 kpc.