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A Young Planetary-Mass Object in the ρ Oph Cloud Core

Marsh, Kenneth A. and Kirkpatrick, J. Davy and Plavchan, Peter (2010) A Young Planetary-Mass Object in the ρ Oph Cloud Core. Astrophysical Journal Letters, 709 (2). L158-L162. ISSN 2041-8205.

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We report the discovery of a young planetary-mass brown dwarf in the ρ Oph cloud core. The object was identified as such with the aid of a 1.5-2.4 μm low-resolution spectrum obtained using the NIRC instrument on the Keck I telescope. Based on the COND model, the observed spectrum is consistent with a reddened (A_V ~ 15-16) brown dwarf whose effective temperature is in the range 1200-1800 K. For an assumed age of 1 Myr, comparison with isochrones further constrains the temperature to ~1400 K and suggests a mass of ~2-3 Jupiter masses. The inferred temperature is suggestive of an early T spectral type, which is supported by spectral morphology consistent with weak methane absorption. Based on its inferred distance (~100 pc) and the presence of overlying visual absorption, it is very likely to be a ρ Oph cluster member. In addition, given the estimated spectral type, it may be the youngest and least massive T dwarf found so far. Its existence suggests that the initial mass function for the ρ Oph star-forming region extends well into the planetary-mass regime.

Item Type:Article
Related URLs:
URLURL TypeDescription DOIArticle
Marsh, Kenneth A.0000-0003-0107-7803
Kirkpatrick, J. Davy0000-0003-4269-260X
Plavchan, Peter0000-0002-8864-1667
Additional Information:© 2010 The American Astronomical Society. Received 2009 October 29; accepted 2009 December 16; published 2010 January 14. We thank the referee, A. Muench, for helpful comments. The 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. The authors wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Mauna Kea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. Our research also utilized the Simbad database, operated at CDS, Strasbourg, France. The work was carried out at IPAC/Caltech and was supported by a grant from the NASA Astrophysics Data Analysis Program and by a Keck PI data award.
Group:Infrared Processing and Analysis Center (IPAC)
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
Subject Keywords:brown dwarfs; infrared: stars; stars: low-mass; stars: pre-main sequence
Issue or Number:2
Record Number:CaltechAUTHORS:20100224-105524585
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Official Citation:A Young Planetary-Mass Object in the ρ Oph Cloud Core Kenneth A. Marsh, J. Davy Kirkpatrick, and Peter Plavchan 2010 ApJ 709 L158-L162 doi: 10.1088/2041-8205/709/2/L158
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:17574
Deposited By: Tony Diaz
Deposited On:02 Mar 2010 17:45
Last Modified:09 Mar 2020 13:19

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