Cloud properties of Nearest Brown Dwarfs Revealed through Spectral Monitoring Study

starweatherWe’ve just reported the first results from our April 2013  campaign to monitor the nearby brown dwarf binary Luhman 16AB, in a paper published in the Astrophysical Journal.  Our results confirm the earlier “flux reversal” seen in FIRE spectroscopy, and allow us to make the first constraints on the cloud coverage fraction and the temperatures of the “clouds” and “holes” in the atmosphere of Luhman 16B.  We also confirm an apparent correlation between rotation period and variability amplitude, which may emerge if cloud features are related to the Rhine’s scale of brown dwarf atmospheres.

[Read more…]

Worldwide Campaign for Luhman 16AB

This week, members of the Cool Star Lab and colleagues in the US, Europe, Chile, and South Africa will be targeting the newly-discovered nearby brown dwarf binary Luhman 16AB (aka WISE 1049-5319).  This very exciting source has been shown to be variable on timescales of hours thanks to data acquired with the TRAPPIST telescope. We’ll be extending this work with photometric and spectroscopic observations in the optical and near-infrared from La Silla Observatory, Cerro Tololo ObservatoryLas Campanas du Pont Observatory, Magellan Telescopes, Keck Observatory, the NASA Infrared Telescope Facility and the South African Large Telescope.  We’ll also be attempting high resolution spectroscopic observations to measure rotational and orbital motions.  Stay tuned!

Screen shot 2013-04-21 at 11.22.52 PM