WD1032 + 011, an inflated brown dwarf in an old eclipsing binary with a white dwarf
Abstract
We present the discovery of only the third brown dwarf known to eclipse a non-accreting white dwarf. Gaia parallax information and multicolour photometry confirm that the white dwarf is cool (9950 ± 150 K) and has a low mass (0.45 ± 0.05 M⊙), and spectra and light curves suggest the brown dwarf has a mass of 0.067 ± 0.006 M⊙ (70MJup) and a spectral type of L5 ± 1. The kinematics of the system show that the binary is likely to be a member of the thick disc and therefore at least 5-Gyr old. The high-cadence light curves show that the brown dwarf is inflated, making it the first brown dwarf in an eclipsing white dwarf-brown dwarf binary to be so.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2020
- DOI:
- 10.1093/mnras/staa1608
- arXiv:
- arXiv:2006.09417
- Bibcode:
- 2020MNRAS.497.3571C
- Keywords:
-
- binaries: eclipsing;
- brown dwarfs;
- white dwarfs;
- Astrophysics - Solar and Stellar Astrophysics;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- Accepted for publication in MNRAS, 11 pages, 7 Figures