Open AccessOptical spectroscopy of a brown dwarf candidate
Author(s) -
Reid I. Neill
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02251.x
Subject(s) - physics , brown dwarf , astrophysics , spectrograph , astronomy , jupiter (rocket family) , radius , stars , parallax , stellar classification , very large telescope , spectroscopy , effective temperature , spectral line , computer security , space shuttle , computer science
We have used the Low‐Resolution Imaging Spectrograph on the Keck II telescope to observe the brown dwarf candidate D04. The spectrum matches that of a spectral type M7 dwarf, implying a photospheric temperature of ≈ 2600 K. This is consistent with the available ( R‐I ) C and ( I‐K ) colours. If the parallax measured by Hawkins et al. is correct, then the implication is that D04 has a radius of ∼ 0.035 R odot; , or one‐third that of Jupiter. This contradicts the predictions made by current stellar models that electron degeneracy leads to nearly constant radii for stars and brown dwarfs at masses below 0.1 M odot; . We suggest that an equally valid interpretation of the data is that D04 is a VB8 analogue at a distance of ≈ 150 pc.