GTC/OSIRIS spectroscopic confirmation of the first L dwarf in Praesepe

Dr. Steve Boudreault

Abstract

Fundamental properties of brown dwarfs, such as luminosity and effective temperature, evolve with age. Large samples of spectroscopically-confirmed substellar objects with well-determined ages and distances are needed to constrain those parameters. We are embarked in a spectroscopic follow-up with GTC/OSIRIS of low-mass member candidates selected in several open clusters to constrain their membership. Here I will present the first L dwarf member in Praesepe confirmed by photometry, astrometry, and spectroscopy. We derived an optical spectral type of L0.3+/-0.4 and a mass placing it at the hydrogen-burning boundary. Considering the measured equivalent width of the gravity-sensitive sodium doublet, and the derived membership probability of ~80% or higher, we conclude that this object is likely to be a true member of Praesepe, with evidence of being a binary system.

About the talk

GTC/OSIRIS spectroscopic confirmation of the first L dwarf in Praesepe
Dr. Steve Boudreault
IAC
Friday May 31, 2013
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