2003/09/30 by Jaiyul Yoo, D. L. DePoy, A. Gal-Yam +16 · 1 citation
Physics and Astronomy · #astro-ph
paper · pdf · doi:10.1086/381241
published as Astrophys.J.603:139-151,2004 · 9 pages, 6 figures, accepted for publication in the Astrophysical Journal
arxiv created 2003/11/07 · arxiv updated 2019/08/17
We analyze OGLE-2003-BLG-262, a relatively short, tE=12.5+-0.1day, microlensing event generated by a point-mass lens transiting the face of a K giant source in the Galactic bulge. We use the resulting finite-source effects to measure the angular Einstein radius, thetaE=195+-17muas, and so constrain the lens mass to the full-width half-maximum interval 0.08 < M/Msun < 0.54. The lens-source relative proper motion is murel = 27+-2 km/s/kpc. Both values are typical of what is expected for lenses detected toward the bulge. Despite the short duration of the event, we detect marginal evidence for a "parallax asymmetry", but argue that this is more likely to be induced by acceleration of the source, a binary lens, or possibly by statistical fluctuations. Although OGLE-2003-BLG-262 is only the second published event to date in which the lens transits the source, such events will become more common with the new OGLE-III survey in place. We therefore give a detailed account of the analysis of this event to facilitate the study of future events of this type.