%0 Journal Article
%T The substellar companion in the eclipsing white dwarf binary SDSS J141126.20+200911.1
%A S. P. Littlefair
%A S. L. Casewell
%A S. G. Parsons
%A V. S. Dhillon
%A T. R. Marsh
%A B. T. G. Gaensicke
%A S. Bloemen
%A S. Catalan
%A P. Irawati
%A L. K. Hardy
%A M. Mcallister
%A M. C. P. Bours
%A Andrea Richichi
%A M. R. Burleigh
%A B. Burningham
%A E. Breedt
%A P. Kerry
%J Physics
%D 2014
%I arXiv
%R 10.1093/mnras/stu1895
%X We present high time resolution SDSS-$g'$ and SDSS-$z'$ light curves of the primary eclipse in SDSS J141126.20+200911.1, together with time-resolved X-Shooter spectroscopy and near-infrared $JHK_{s}$ photometry. Our observations confirm the substellar nature of the companion, making SDSS J141126.20+200911.1 the first eclipsing white dwarf/brown dwarf binary known. We measure a (white dwarf model dependent) mass and radius for the brown dwarf companion of $M_{2} = 0.050 \pm 0.002$ $M_{\odot}$ and $R_{2} = 0.072 \pm 0.004$ $M_{\odot}$, respectively. The lack of a robust detection of the companion light in the $z'$-band eclipse constrains the spectral type of the companion to be later than L5. Comparing the NIR photometry to the expected white dwarf flux reveals a clear $K_s$-band excess, suggesting a spectral type in the range L7-T1. The radius measurement is consistent with the predictions of evolutionary models, and suggests a system age in excess of three Gyr. The low companion mass is inconsistent with the inferred spectral type of L7-T1, instead predicting a spectral type nearer T5. This indicates that irradiation of the companion in SDSS J1411 could be causing a significant temperature increase, at least on one hemisphere.
%U http://arxiv.org/abs/1409.3125v1