The substellar companion in the eclipsing white dwarf binary SDSS J141126.20+200911.1

• DOI: 10.1093/mnras/stu1895
• Publication Date: 2014-10-16T03:41:33Z
• Authors: S. P. Littlefair; S. L. Casewell; S. G. Parsons; V. S. Dhillon; T. R. Marsh; B. T. Gänsicke; S. Bloemen; S. Catalan; P. Irawati; L. K. Hardy; M. Mcallister; M. C. P. Bours; Andrea Richichi; M. R. Burleigh; B. Burningham; E. Breedt; P. Kerry
• Keywords: Eclipse; Effective temperature

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 near-infrared $JHK_{s}$ photometry. Our observations confirm substellar nature companion, making J141126.20+200911.1 first eclipsing white dwarf/brown dwarf binary known. measure a (white model dependent) mass radius for brown companion $M_{2} = 0.050 \pm 0.002$ $M_{\odot}$ $R_{2} 0.072 0.004$ $M_{\odot}$, respectively. The lack robust detection $z'$-band constrains spectral type to be later than L5. Comparing NIR photometry expected flux reveals clear $K_s$-band excess, suggesting range L7-T1. measurement is consistent predictions evolutionary models, suggests system age excess three Gyr. low inconsistent inferred L7-T1, instead predicting nearer T5. This indicates that irradiation J1411 could causing significant temperature increase, at least on one hemisphere.