Poster Abstracts

Name/Affiliation:  Eugenio Victor Garcia (Lowell Observatory)

Title:  Extreme High-Spatial Resolution Imaging of the Lowest Mass Pleiades

The Pleiades is an ideal venue for studying observed discrepancy in brown dwarf binary frequency between field (~few Gyr) and young star-forming region (~few Myr) populations given its intermediate age (120+/-20~Myr). We have obtained Hubble Space Telescope Wide Field Camera 3 UVIS observations of a sample of the most recently discovered <~40 Mjup brown dwarfs in the Pleiades. Given the excellent stability of the WFC3 point-spread function, we have developed a binary fitting technique which allows us to search for the existence of companions at tight separations of ~lambda/2D (30 mas, 4 AU). Such angular resolution is only matched by aperture masking techniques on 10-m class telescopes and visible light AO at Magellan. These constraints allow us to test if our sample is consistent with the binary frequency of field brown dwarfs at separations of 5 AU, where most companions are known to exist. This high angular resolution binary fitting technique can be extended to WFPC2, NICMOS and ACS observations of Pleiades and field brown dwarfs, allowing for a search of companions at tight separations.