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arXiv · 1412.6363

Multiwaveband photometry of the irradiated brown dwarf WD0137-349B

S. L. Casewell·K. A. Lawrie·P. F. L. Maxted·M. S. Marley·J. J. Fortney·P. B. Rimmer·S. P. Littlefair·G. Wynn·M. R. Burleigh·Ch. Helling
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Abstract

WD0137-349 is a white dwarf-brown dwarf binary system in a 116 minute orbit. We present radial velocity observations and multiwaveband photometry from V, R and I in the optical, to J, H and Ks in the near-IR and [3.6], [4.5], [5.8] and [8.0] microns in the mid-IR. The photometry and lightcurves show variability in all wavebands, with the amplitude peaking at [4.5] microns, where the system is also brightest. Fluxes and brightness temperatures were computed for the heated and unheated atmosphere of the brown dwarf (WD0137-349B) using synthetic spectra of the white dwarf using model atmosphere simulations. We show that the flux from the brown dwarf dayside is brighter than expected in the Ks and [4.5] micron bands when compared to models of irradiated brown dwarfs with full energy circulation and suggest this over-luminosity may be attributed to H2 fluorescence or H3+ being generated in the atmosphere by the UV irradiation.

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S. L. Casewell, K. A. Lawrie, P. F. L. Maxted, M. S. Marley, J. J. Fortney, P. B. Rimmer, S. P. Littlefair, G. Wynn, M. R. Burleigh, Ch. Helling. 2014-12-22. Multiwaveband photometry of the irradiated brown dwarf WD0137-349B. https://doi.org/10.1093/mnras%2Fstu2721

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