Document 
| Abstract | PDF (208 KB) | PS (311 KB) | References | HTML | Simbad Objects | NASA ADS Abstract Service |
Free access article
A&A 397, L5-L8 (2003)
DOI: 10.1051/0004-6361:20021714
Letter
First radius measurements of very low mass stars with the VLTI
D. Ségransan1, P. Kervella2, T. Forveille3, 4 and D. Queloz11 Observatoire de Genève, 51 chemin des maillettes, 1290 Sauverny, Switzerland
2 European Southern Observatory, Casilla 19001, Vitacura, Santiago 19, Chile
3 Observatoire de Grenoble, BP 53X, 38041 Grenoble Cedex, France
4 Canada-France-Hawaii Telescope Corporation, PO Box 1597, Kamuela, HI 96743, USA
(Received 15 October 2002 / Accepted 21 November 2002 )
Abstract
We present 4 very low mass stars radii measured with the VLTI using the 2.2
m VINCI test instrument.
The observations were carried out during the commissioning of the 104-meter-baseline with two
8-meter-telescopes. We measure angular diameters of 0.7-1.5 mas with accuracies
of 0.04-0.11 mas, and for spectral type ranging from M0V to M5.5V.
We determine an empirical mass-radius relation for M dwarfs based on all available radius measurements.
The observed relation agrees well with theoretical models at the present accuracy level, with possible discrepancy around
0.5-0.8
that needs to be confirmed.
In the near future, dozens of M
dwarfs radii will be measured with 0.1-1% accuracy, with the VLTI, thanks to the improvements expected from the
near infrared instrument AMBER.
This will bring strong observational constraints on both atmosphere and interior physics.
Key words: stars: low-mass, brown dwarfs -- stars: fundamental parameters -- techniques: interferometric
Offprint request: D. Ségransan, Damien.Segransan@obs.unige.ch
SIMBAD Objects
© ESO 2003