EDP Sciences
Free access
Volume 411, Number 3, December I 2003
Page(s) L493 - L496
Section Letters
DOI http://dx.doi.org/10.1051/0004-6361:20031602

A&A 411, L493-L496 (2003)
DOI: 10.1051/0004-6361:20031602


Probing the atmosphere of a solar-like star by galactic microlensing at high magnification

F. Abe1, D. P. Bennett2, I. A. Bond3, J. J. Calitz4, A. Claret5, K. H. Cook6, Y. Furuta1, A. Gal-Yam7, J.-F. Glicenstein8, J. B. Hearnshaw9, P. H. Hauschildt10, D. Kent9, P. M. Kilmartin9, Y. Kurata1, K. Masuda1, D. Maoz7, Y. Matsubara1, P. J. Meintjes4, M. Moniez1, Y. Muraki1, S. Noda1, E. O. Ofek7, K. Okajima1, L. Philpott11, N. J. Rattenbury11, S. H. Rhie2, T. Sako1, D. J. Sullivan12, T. Sumi13, D. M. Terndrup14, P. J. Tristram9, T. Yanagisawa1 and P. C. M. Yock11

1  Solar Terrestrial Environment Laboratory, Nagoya University, Nagoya 464-01, Japan
2  Department of Physics, Notre Dame University, Notre Dame, IN 46556, USA
3  Institute for Astronomy, University of Edinburgh, Edinburgh, EH9 3HJ, UK
4  Department of Physics, University of the Free State, Bloemfontein, South Africa
5  Instituto de Astrofísica de Andalucía, CSIC, Apartado 3004, 18080 Granada, Spain
6  Institute for Geophysics and Planetary Physics, Lawrence Livermore National Laboratory, CA 94563, USA
7  School of Physics and Astronomy, Tel-Aviv University, Tel-Aviv 69978, Israel
8  CEA, DSM, DAPNIA, Centre d'Études de Saclay, 91191 Gif-sur-Yvette Cedex, France
9  Department of Physics and Astronomy, University of Canterbury, Private Bag 4800, Christchurch, New Zealand
10  Universität Hamburg, Sternwarte, Gojenbergsweg 112, 21029 Hamburg, Germany
11  Faculty of Science, University of Auckland, Private Bag 92019, Auckland, New Zealand
12  School of Chemical and Physical Sciences, Victoria University, PO Box 600, Wellington, New Zealand
13  Department of Astrophysical Sciences, Princeton University, Princeton NJ 08544, USA
14  Department of Astronomy, Ohio State University, Columbus OH 43210, USA

(Received 2 July 2003 / Accepted 13 Octobre 2003 )

We report a measurement of limb darkening of a solar-like star in the very high magnification microlensing event MOA 2002-BLG-33. A 15 hour deviation from the light curve profile expected for a single lens was monitored intensively in  V and  I passbands by five telescopes spanning the globe. Our modelling of the light curve showed the lens to be a close binary system whose centre-of-mass passed almost directly in front of the source star. The source star was identified as an F8-G2 main sequence turn-off star. The measured stellar profiles agree with current stellar atmosphere theory to within ~4% in two passbands. The effective angular resolution of the measurements is  <1  $\mu$as. These are the first limb darkening measurements obtained by microlensing for a Solar-like star.

Key words: techniques: high angular resolution -- techniques: gravitational microlensing -- stars: limb darkening -- stars: individual: MOA 2002-BLG-33

Offprint request: I. A. Bond, iab@roe.ac.uk

SIMBAD Objects

© ESO 2003