We present the discovery of the eclipsing double white dwarf (WD) binary WDJ 022558.21-692025.38 that has an orbital period of 47.19 min. Following identification with the Transiting Exoplanet Survey Satellite, we obtained time-series ground based spectroscopy and high-speed multi-band ULTRACAM photometry which indicate a primary DA WD of mass 0.40 +- 0.04 Msol and a 0.28 +- 0.02 Msol mass secondary WD, which is likely of type DA as well. The system becomes the third-closest eclipsing double WD binary discovered with a distance of approximately 400 pc and will be a detectable source for upcoming gravitational wave detectors in the mHz frequency range. Its orbital decay will be measurable photometrically within 10 yrs to a precision of better than 1%. The fate of the binary is to merge in approximately 41 Myr, likely forming a single, more massive WD.
@article{arxiv.2308.00036,
title = {An Eclipsing 47 minute Double White Dwarf Binary at 400 pc},
author = {James Munday and P. -E. Tremblay and J. J. Hermes and Brad Barlow and Ingrid Pelisoli and T. R. Marsh and Steven G. Parsons and David Jones and S. O. Kepler and Alex Brown and S. P. Littlefair and R. Hegedus and Andrzej Baran and Elmé Breedt and V. S. Dhillon and Martin J. Dyer and Matthew J. Green and Mark R. Kennedy and Paul Kerry and Isaac D. Lopez and Alejandra D. Romero and Dave Sahman and Hannah L. Worters},
journal= {arXiv preprint arXiv:2308.00036},
year = {2023}
}
Comments
Accepted for publication in MNRAS, 8 pages + 2 appendix pages, 6 figures