EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 426/1 Article
Free access article

Issue A&A
Volume 426, Number 1, October IV 2004
Page(s) 297 - 307
Section Stellar atmospheres
DOI http://dx.doi.org/10.1051/0004-6361:20035930



A&A 426, 297-307 (2004)
DOI: 10.1051/0004-6361:20035930

The angular sizes of dwarf stars and subgiants

Surface brightness relations calibrated by interferometry
P. Kervella1, 2, F. Thévenin3, E. Di Folco4 and D. Ségransan5

1  LESIA, UMR 8109, Observatoire de Paris-Meudon, 5 place Jules Janssen, 92195 Meudon Cedex, France
    e-mail: Pierre.Kervella@obspm.fr
2  European Southern Observatory, Alonso de Cordova 3107, Casilla 19001, Vitacura, Santiago 19, Chile
3  Observatoire de la Côte d'Azur, BP 4229, 06304 Nice Cedex 4, France
4  European Southern Observatory, Karl-Schwarzschild-str. 2, 85748 Garching, Germany
5  Observatoire de Genève, 1290 Sauverny, Switzerland

(Received 22 December 2003 / Accepted 17 June 2004 )

Abstract
The availability of a number of new interferometric measurements of Main Sequence and subgiant stars makes it possible to calibrate the surface brightness relations of these stars using exclusively direct angular diameter measurements. These empirical laws make it possible to predict the limb darkened angular diameters $\theta_{\rm LD}$ of dwarfs and subgiants using their dereddened Johnson magnitudes, or their effective temperature. The smallest intrinsic dispersions of $\sigma \le 1\%$ in $\theta_{\rm LD}$ are obtained for the relations based on the K and L magnitudes, for instance $\log \theta_{\rm LD} = 0.0502\,(B-L) + 0.5133 - 0.2\,L$ or $\log \theta_{\rm LD} = 0.0755\,(V-K) + 0.5170 - 0.2\rm\,K$. Our calibrations are valid between the spectral types A0 and M2 for dwarf stars (with a possible extension to later types when using the effective temperature), and between A0 and K0 for subgiants. Such relations are particularly useful for estimating the angular sizes of calibrators for long-baseline interferometry from readily available broadband photometry.


Key words: stars: fundamental parameters -- techniques: interferometric

SIMBAD Objects



© ESO 2004


What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.