The Lowest-mass Member of the β Pictoris Moving Group
Abstract
We present spectral and kinematic evidence that 2MASS J06085283–2753583 (M8.5γ) is a member of the β Pictoris Moving Group (BPMG, age ~12 Myr), making it the latest-type known member of this young, nearby association. We confirm low-gravity spectral morphology at both medium and high resolutions in the near-infrared. We present new radial velocity and proper motion measurements, and use these to calculate galactic location and space motion consistent with other high-probability members of the BPMG. The predicted mass range consistent with the object's effective temperature, surface gravity, spectral type, and age is 15-35 M_(Jup), placing 2MASS 0608–27 well within the brown dwarf mass regime. 2MASS J06085283–2753583 is thus confidently added to the short list of very low mass, intermediate age benchmark objects that inform ongoing searches for the lowest-mass members of nearby young associations.
Additional Information
© 2010 American Astronomical Society. Received 2010 March 17; accepted 2010 April 29; published 2010 May 13. The authors thank K. Allers for her comments on an early draft of this Letter, J. D. Kirkpatrick, M. Cushing, M. Simon, J. Schlieder, and S. Metchev for useful discussions, and the anonymous referee for helpful comments. Observing and/or data reduction assistance were provided by M. R. McGovern and G. Gimeno. Support for this work was provided by NASA through the Spitzer Space Telescope Fellowship Program, through a contract issued by JPL/Caltech. The authors wish to acknowledge the staff of the Keck, Cerro Tololo, and IRTF observatories for their outstanding support. Data presented herein were obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National Aeronautics and Space Administration. The observatory was made possible by the generous financial support of the W. M. Keck Foundation. This research has made use of the NASA/IPAC Infrared Science Archive operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This publication makes use of data from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center, funded by the National Aeronautics and Space Administration and the National Science Foundation. This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France and NASA's Astrophysics Data System. Finally, the authors wish to extend special thanks to those of Hawaiian ancestry on whose sacred mountain we are privileged to be guests. Facilities: Keck:II (NIRSPEC), IRTF (SpeX), Blanco (ISPI), Gemini:South (Phoenix)Attached Files
Published - Rice2010p10557Astrophys_J_Lett.pdf
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Additional details
- Eprint ID
- 18909
- Resolver ID
- CaltechAUTHORS:20100706-101456324
- NASA Spitzer Fellowship
- Created
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2010-07-06Created from EPrint's datestamp field
- Updated
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2021-11-08Created from EPrint's last_modified field
- Caltech groups
- Infrared Processing and Analysis Center (IPAC)