Multiplicity of Young Brown Dwarfs in Cha I

Viki Joergens, Eike Guenther, Ralph Neuhäuser, Fernando Comerón, Nuria Huélamo, João Alves, Wolfgang Brandner

Publications: Contribution to bookContribution to proceedings

Abstract

How frequent are brown dwarf binaries? Do brown dwarfs have planets? Are current theoretical pre-main-sequence evolutionary tracks valid down to the substellar regime? - Any detection of a companion to a brown dwarf takes us one step forward towards answering these basic questions of star formation. We report here on a search for spectroscopic and visual companions to young brown dwarfs in the Cha I star forming cloud. Based on spectra taken with UVES at the VLT, we found significant radial velocity (RV) variations for five bona-fide and candidate brown dwarfs in Cha I. They can be caused by either a (substellar or planetary) companion or stellar activity. A companion causing the detected RV variations would have about a few Jupiter masses. We are planning further UVES observations in order to explore the nature of the detected RV variations. We also found that the RV dispersion is only ˜2 km/s indicating that there is probably no run-away brown dwarf among them. Additionally a search for companions by direct imaging with the HST and SOFI (NTT) has yielded to the detection of a few companion candidates in larger orbits.
Original languageEnglish
Title of host publicationThe Origin of Stars and Planets: The VLT View
Subtitle of host publicationProceedings of the ESO Workshop Held in Garching, Germany, 24-27 April 2001
EditorsJoão F. Alves , Mark J. McCaughrean
Place of PublicationBerlin
PublisherSpringer-Verlag Berlin-Heidelberg
Pages127
ISBN (Electronic)978-3-540-46031-2
ISBN (Print)978-3-540-43541-9
DOIs
Publication statusPublished - 2002

Publication series

SeriesESO Astrophysics Symposia
ISSN1431-2433

Austrian Fields of Science 2012

  • 103004 Astrophysics

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