OGLE 2004-BLG-254: a K3 III Galactic Bulge Giant spatially resolved by a single microlens
Abstract
We present an analysis of OGLE 2004-BLG-254, a high-magnification and relatively short duration microlensing event in which the source star, a Bulge K3-giant, has been spatially resolved by a point-like lens. We have obtained dense photometric coverage of the event light curve with OGLE and PLANET telescopes, as well as a high signal-to-noise ratio spectrum taken while the source was still magnified by 20, using the UVES/VLT spectrograph. Our dense coverage of this event allows us to measure limb darkening of the source star in the I and R bands. We also compare previous measurements of linear limb-darkening coefficients involving GK-giant stars with predictions from ATLAS atmosphere models. We discuss the case of K-giants and find a disagreement between limb-darkening measurements and model predictions, which may be caused by the inadequacy of the linear limb-darkening law.
Cite
@article{arxiv.astro-ph/0609290,
title = {OGLE 2004-BLG-254: a K3 III Galactic Bulge Giant spatially resolved by a single microlens},
author = {A. Cassan and J. -P. Beaulieu and P. Fouque and S. Brillant and M. Dominik and J. Greenhill and D. Heyrovsky and K. Horne and U. G. Jorgensen and D. Kubas and H. C. Stempels and C. Vinter and M. D. Albrow and D. Bennett and J. A. R. Caldwell and J. J. Calitz and K. Cook and C. Coutures and D. Dominis and J. Donatowicz and K. Hill and M. Hoffman and S. Kane and J. -B. Marquette and R. Martin and P. Meintjes and J. Menzies and V. R. Miller and K. R. Pollard and K. C. Sahu and J. Wambsganss and A. Williams and A. Udalski and M. K. Szymanski and M. Kubiak and G. Pietrzynski and I. Soszynski and K. Zebrun and O. Szewczyk and L. Wyrzykowski},
journal= {arXiv preprint arXiv:astro-ph/0609290},
year = {2009}
}
Comments
14 pages, 8 figures, accepted for publication in A&A (04/09/2006)