We present the discovery of only the third brown dwarf known to eclipse a non-accreting white dwarf. Gaia parallax information and multi-colour photometry confirm that the white dwarf is cool (9950±150K) and has a low mass (0.45±0.05~MSun), and spectra and lightcurves suggest the brown dwarf has a mass of 0.067 ±0.006 MSun (70 MJup) 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 disk and therefore at least 5 Gyr old. The high cadence lightcurves show that the brown dwarf is inflated, making it the first brown dwarf in an eclipsing white dwarf-brown dwarf binary to be so.
@article{arxiv.2006.09417,
title = {WD1032+011, an inflated brown dwarf in an old eclipsing binary with a white dwarf},
author = {S. L. Casewell and C. Belardi and S. G. Parsons and S. P. Littlefair and I. P. Braker and J. J. Hermes and J. Debes and Z. Vanderbosch and M. R. Burleigh and B. T. Gaensicke and V. S. Dhillon and T. R. Marsh and D. E. Winget and K. I. Winget},
journal= {arXiv preprint arXiv:2006.09417},
year = {2020}
}
Comments
Accepted for publication in MNRAS, 11 pages, 7 Figures