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Periodic photometric variability of the brown dwarf Kelu-1

F. J. Clarke·C. G. Tinney·K. R. Covey
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Abstract

We have detected a strong periodicity of 1.80+/-0.05 hours in photometric observations of the brown dwarf Kelu-1. The peak-to-peak amplitude of the variation is ~1.1% (11.9+/-0.8 mmag) in a 41nm wide filter centred on 857nm and including the dust/temperature sensitive TiO & CrH bands. We have identified two plausible causes of variability: surface features rotating into- and out-of-view and so modulating the light curve at the rotation period; or, elliposidal variability caused by an orbiting companion. In the first scenario, we combine the observed vsin(i) of Kelu-1 and standard model radius to determine that the axis of rotation is inclined at 65+/-12 degrees to the line of sight.

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F. J. Clarke, C. G. Tinney, K. R. Covey. 2002-01-10. Periodic photometric variability of the brown dwarf Kelu-1. https://doi.org/10.1046/j.1365-8711.2002.05308.x

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