Discovery of a Low-mass Companion Around HR 3549
We report the discovery of a low-mass companion to HR 3549, an A0V star surrounded by a debris disk with a warm excess detected by WISE at 22 μm (10σ significance). We imaged HR 3549 B in the L band with NAOS-CONICA, the adaptive optics infrared camera of the Very Large Telescope, in January 2013 and confirmed its common proper motion in 2015 January. The companion is at a projected separation of ≃80 AU and position angle of ≃157°, so it is orbiting well beyond the warm disk inner edge of r > 10 AU. Our age estimate for this system corresponds to a companion mass in the range 15–80 M_J, spanning the brown dwarf regime, and so HR 3549 B is another recent addition to the growing list of brown dwarf desert objects with extreme mass ratios. The simultaneous presence of a warm disk and a brown dwarf around HR 3549 provides interesting empirical constraints on models of the formation of substellar companions.
© 2015 The American Astronomical Society. Received 2015 July 1; accepted 2015 August 21; published 2015 September 28. The first author is grateful to Prof. Lynne Hillenbrand (Caltech) and Ben Zuckerman (UCLA) for their advice and comments. T.J.D is supported by the National Science Foundation Graduate Research Fellowship under grant No. DGE1144469. M.B. is supported by a NASA Space Technology Research fellowship, grant No. NNX13AN42H. This publication makes use of data products from the Wide-field Infrared Survey Explorer, which is a joint project of the University of California, Los Angeles, and the Jet Propulsion Laboratory/California Institute of Technology, funded by the National Aeronautics and Space Administration. Facility: Very Large Telescope.
Submitted - 1509.05689.pdf
Published - Mawet_2015p103.pdf