MOA 2003-BLG-37: A Bulge Jerk-Parallax Microlens Degeneracy
Abstract
We analyze the Galactic bulge microlensing event MOA-2003-BLG-37. Although the Einstein timescale is relatively short, t_e=43 days, the lightcurve displays deviations consistent with parallax effects due to the Earth's accelerated motion. We show that the chi^2 surface has four distinct local minima that are induced by the ``jerk-parallax'' degeneracy, with pairs of solutions having projected Einstein radii, \tilde r_e = 1.76 AU and 1.28 AU, respectively. This is the second event displaying such a degeneracy and the first toward the Galactic bulge. For both events, the jerk-parallax formalism accurately describes the offsets between the different solutions, giving hope that when extra solutions exist in future events, they can easily be found. However, the morphologies of the chi^2 surfaces for the two events are quite different, implying that much remains to be understood about this degeneracy.
Keywords
Cite
@article{arxiv.astro-ph/0401250,
title = {MOA 2003-BLG-37: A Bulge Jerk-Parallax Microlens Degeneracy},
author = {B. -G. Park and D. L. DePoy and B. S. Gaudi and A. Gould and C. Han and R. W. Pogge and F. Abe and D. P. Bennett and I. A. Bond and S. Eguchi and Y. Furuta and J. B. Hearnshaw and K. Kamiya and P. M. Kilmartin and Y. Kurata and K. Masuda and Y. Matsubara and Y. Muraki and S. Noda and K. Okajima and N. J. Rattenbury and T. Sako and T. Sekiguchi and D. J. Sullivan and T. Sumi and P. J. Tristram and T. Yanagisawa and P. C. M. Yock},
journal= {arXiv preprint arXiv:astro-ph/0401250},
year = {2009}
}
Comments
19 pages, 3 figures, 1 table, ApJ, in press, 1 July 2004