Multiwaveband photometry of the irradiated brown dwarf WD0137-349B

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

Abstract

WD0137-349 is a white dwarf–brown dwarf binary system in a 116 min 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] µm in the mid-IR. The photometry and light curves show variability in all wavebands, with the amplitude peaking at [4.5] µm, 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] µm bands when compared to models of irradiated brown dwarfs with full energy circulation and suggest this overluminosity may be attributed to H2 fluorescence or H+3 being generated in the atmosphere by the UV irradiation.

Citation

Casewell, S., Lawrie, K., Maxted, P., Marley, M., Fortney, J., Rimmer, P., …Helling, C. (2015). Multiwaveband photometry of the irradiated brown dwarf WD0137-349B. Monthly Notices of the Royal Astronomical Society, 447(4), 3218 -3226. https://doi.org/10.1093/mnras/stu2721

• Journal Article Type: Article
• Acceptance Date: Dec 18, 2014
• Online Publication Date: Jan 15, 2015
• Publication Date: Mar 11, 2015
• Publicly Available Date: May 26, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 447
• Issue: 4
• Pages: 3218 -3226
• DOI: https://doi.org/10.1093/mnras/stu2721
• Keywords: stars, close binaries, brown dwarfs, white dwarfs
• Publisher URL: http://dx.doi.org/10.1093/mnras/stu2721