@article{GhoshDePoyGalYametal.2004,
  author    = {Ghosh, H. and DePoy, D. L. and Gal-Yam, A. and Gaudi, B. S. and Gould, A. and Han, C. and Lipkin, Y. and Maoz, D. and Ofek, E. O. and Park, B. G. and Pogge, R. W. and Salim, S. and Abe, Fumio and Bennett, David P. and Bond, I. A. and Eguchi, S. and Furuta, Y. and Hearnshaw, John B. and Kamiya, K. and Kilmartin, Pam M. and Kurata, Y. and Masuda, Kimiaki and Matsubara, Yutaka and Muraki, Y. and Noda, S. and Okajima, K. and Rattenbury, N. J. and Sako, T. and Sekiguchi, T. and Sullivan, D. J. and Sumi, T. and Tristram, P. J. and Yanagisawa, T. and Yock, P. C. M. and Udalski, A. and Soszynski, I. and Wyrzykowski, X. and Kubiak, Marcin and Szymanski, M. K. and Pietrzynski, G. and Szewczyk, O. and Zebru,},
  title     = {Potential direct single-star mass measurement},
  issn      = {0004-637X},
  year      = {2004},
  abstract  = {We analyze the light curve of the microlensing event OGLE-2003-BLG-175/MOA-2003-BLG-45 and show that it has two properties that, when combined with future high-resolution astrometry, could lead to a direct, accurate measurement of the lens mass. First, the light curve shows clear signs of distortion due to the Earth's accelerated motion, which yields a measurement of the projected Einstein radius (r) over tilde (E). Second, from precise astrometric measurements, we show that the blended light in the event is coincident with the microlensed source to within about 15 mas. This argues strongly that this blended light is the lens and hence opens the possibility of directly measuring the lens- source relative proper motion mu(rel) and so the mass M=(c(2)/4G)mu(rel)t(E)(r) over tilde (E), where t(E) is the measured Einstein timescale. While the light-curve-based measurement of (r) over tildeE is, by itself, severely degenerate, we show that this degeneracy can be completely resolved by measuring the direction of proper motion mu(rel)},
  language  = {en}
}
@article{JiangDePoyGalYametal.2004,
  author    = {Jiang, G. F. and DePoy, D. L. and Gal-Yam, A. and Gaudi, B. S. and Gould, A. and Han, C. and Lipkin, Y. and Maoz, D. and Ofek, E. O. and Park, B. G. and Pogge, R. W. and Udalski, A. and Kubiak, Marcin and Szymanski, M. K. and Szewczyk, O. and Zerbrun, K. and Wyrzykowski, L. and Soszynski, I. and Pietrzynski, G. and Albrow, Michael D. and Beaulieu, Jean-Philippe and Caldwell, John A. R. and Cassan, A. and Coutures, C. and Dominik, M. and Donatowicz, J. and Fouque, P. and Greenhill, John and Hill, K. and Horne, Keith and Jorgensen, S. F. and Jorgensen, Uffe Grae and Kane, Stephen R. and Kubas, Daniel and Martin, Ralph and Menzies, J. W. and Pollard, R. and Sahu, K. C. and Wambsganss, Joachim and Watson, R. and Williams, A.},
  title     = {OGLE-2003-BLG-238 : Microlensing mass estimate of an isolated star},
  issn      = {0004-637X},
  year      = {2004},
  abstract  = {Microlensing is the only known direct method to measure the masses of stars that lack visible companions. In terms of microlensing observables, the mass is given by M (c(2)/4G)(r) over tilde (E)theta(E) and so requires the measurement of both the angular Einstein radius theta(E) and the projected Einstein radius (r) over tilde (E). Simultaneous measurement of these two parameters is extremely rare. Here we analyze OGLE-2003-BLG-238, a spectacularly bright (I-min 10.3), high-magnification (A(max) 170) microlensing event. Pronounced finite-source effects permit a measurement of theta(E) = 650 muas. Although the timescale of the event is only t(E) 38 days, one can still obtain weak constraints on the microlens parallax: 4.4 AU < <(r)over tilde>(E) < 18 AU at the 1 \&sigma; level. Together these two parameter measurements yield a range for the lens mass of 0.36 M-\&ODOT; < M < 1.48 M-\&ODOT;. As was the case for MACHO- LMC-5, the only other single star (apart from the Sun) whose mass has been determined from its gravitational effects, this estimate is rather crude. It does, however, demonstrate the viability of the technique. We also discuss future prospects for single-lens mass measurements},
  language  = {en}
}