An eclipsing 47 minute double white dwarf binary at 400 pc

Abstract

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 M⊙ and a 0.28 ± 0.02 M⊙ 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.

Metadata

Authors/Creators:

Munday, J. https://orcid.org/0000-0002-1872-5398
Tremblay, P.-E.
Hermes, J.J. https://orcid.org/0000-0001-5941-2286
Barlow, B.
Pelisoli, I. https://orcid.org/0000-0003-4615-6556
Marsh, T.R. https://orcid.org/0000-0002-2498-7589
Parsons, S.G. https://orcid.org/0000-0002-2695-2654
Jones, D. https://orcid.org/0000-0003-3947-5946
Kepler, S.O. https://orcid.org/0000-0002-7470-5703
Brown, A. https://orcid.org/0000-0002-3316-7240
Littlefair, S.P.
Hegedus, R.
Baran, A. https://orcid.org/0000-0001-6446-6617
Breedt, E. https://orcid.org/0000-0001-6180-3438
Dhillon, V.S. https://orcid.org/0000-0003-4236-9642
Dyer, M.J. https://orcid.org/0000-0003-3665-5482
Green, M.J. https://orcid.org/0000-0002-0948-4801
Kennedy, M.R. https://orcid.org/0000-0001-6894-6044
Kerry, P.
Lopez, I.D.
Romero, A.D.
Sahman, D.
Worters, H.L.

© 2023 The Authors. Except as otherwise noted, this author-accepted version of a journal article published in Monthly Notices of the Royal Astronomical Society is made available under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/

Keywords:

binaries: close; individual: WDJ 022558.21−692025.38; stars: white dwarfs; gravitational waves

Dates: