The Zwicky Transient Facility has begun to discover binary systems with orbital periods that are less than 1\,hr. Combined with dedicated follow-up systems, which allow for high-cadence photometry of these sources, systematic confirmation and characterization of these sources are now possible. Here, we report the discovery of ZTF J190125.42+530929.5, a 40.6\,min orbital period, eclipsing double white-dwarf binary. Both photometric and spectroscopic modeling confirm its nature, yielding an estimated inclination of i=86.2−0.2+0.6degrees and primary and secondary effective temperatures of Teff=28,000−500+500K and Teff=17,600−400+400K respectively. This system adds to a growing list of sources for future gravitational-wave detectors and contributes to the demographic analysis of double degenerates.
@article{arxiv.2004.00456,
title = {ZTF J1901+5309: A 40.6-Minute Orbital Period Eclipsing Double White Dwarf System},
author = {Michael W. Coughlin and Kevin Burdge and E. Sterl Phinney and Jan van Roestel and Eric C. Bellm and Richard G. Dekany and Alexandre Delacroix and Dmitry A. Duev and Michael Feeney and Matthew J. Graham and S. R. Kulkarni and Thomas Kupfer and Russ R. Laher and Frank J. Masci and Thomas A. Prince and Reed Riddle and Philippe Rosnet and Roger Smith and Eugene Serabyn and Richard Walters},
journal= {arXiv preprint arXiv:2004.00456},
year = {2020}
}