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Accurate masses of very low mass stars
IV. Improved mass-luminosity relations *
X. Delfosse 1,
T. Forveille 2,3,
D. Ségransan 3,
J.-L. Beuzit 3,2,
S. Udry 4,
C. Perrier 3 and
M. Mayor 4
Received 21 July 2000 / Accepted 28 September 2000
We present improved visual and near-infrared empirical mass-luminosity relations for very low mass stars (M0.6 ). These relations make use of all stellar masses in this range known with better than 10% accuracy, most of which are new determinations with 0.2 to 5% accuracy from our own programme, presented in a companion paper.
As predicted by stellar structure models, the metallicity dispersion of the field populations induces a large scatter around the mean V band relation, while the infrared relations are much tighter. The agreement of the observed infrared mass-luminosity relations with the theoretical relations of Baraffe et al. (1998) and Siess et al. (2000) is impressive, while we find an increasingly significant discrepancy in the V band for decreasing masses. The theoretical mass-luminosity relation which is insufficiently steep, and has introduced significant errors in the local stellar mass functions derived from V band luminosity functions.
Key words: stars: binaries: general stars: binaries: spectroscopic stars: binaries: visual stars: low-mass, brown dwarfs techniques: radial velocities stars: late-type
Send offprint requests to: Xavier Delfosse (firstname.lastname@example.org)
Online publication: December 15, 2000