An L0 dwarf companion in the brown dwarf desert, at 30 AU

T. Forveille, D. Ségransan, P. Delorme, E. L. Martín, X. Delfosse, J. A. Acosta-Pulido, J.-L. Beuzit, A. Manchado, M. Mayor, C. Perrier, S. Udry
2004 Astronomy and Astrophysics  
We present the discovery of an L0 companion to the nearby M1.5 dwarf G 239-25, at a projected distance of 31 AU. It is the faintest companion discovered so far in our adaptive optics survey of all known M dwarfs within 12 pc, and it lies at the stellar/substellar limit. Given the assumed age of the primary star, the companion is likely an extremely low mass star. The long orbital period of G 239-25 AB ($\approx 100$ years) precludes a direct mass determination, but the relatively wide angular
more » ... vely wide angular separation will allow detailed analyses of its near infrared and visible spectra.
doi:10.1051/0004-6361:200400069 fatcat:2l37o5w4s5fcnhdrq5ywemdoju