PI: Aren Heinze, Stony Brook University, firstname.lastname@example.org
Address: Physics Department, State University of New York, Stony Brook, NY 11794-3800, USA
CoI: Stanimir Metchev, Stony Brook University
CoI: Daniel Apai, University of Arizona
CoI: Davin Flateau, University of Arizona
Title: Wild Weather: Do Rapid Cloud Changes Mask Rotational Modulation of Brown Dwarf Variability?
Abstract: We will probe the timescale on which clouds can evolve on four variable L dwarfs identified through our `Weather on Other Worlds' Spitzer Space Telescope program. Specifically, the observations we propose will test the `masking hypothesis' of Bailer-Jones and Mundt (2001), which envisions L dwarf clouds changing so quickly that the expected rotationally modulated photometric variability is masked, and only non-periodic variations can be detected. The masking hypothesis implies that clouds on at least some L dwarfs change hundreds to thousands of times faster than on Jupiter and Saturn, and at least tens of times faster than on T dwarfs. Our Spitzer data as well as previously published ground based observations suggest that some, but not all, L dwarfs behave this way. By monitoring four known variable L dwarfs for a longer interval than that of the Spitzer observations and most previous ground based studies, we will evaluate the prevalence of strong non-periodic variations, perform a comparative study of the cloud evolution timescales on different L dwarfs, and take a first step toward understanding why clouds seem to vary at such different rates on different objects.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360