The MACHO Project: Exotic Microlensing from GMAN

Session 47 - Microlensing.
Display session, Tuesday, January 16
North Banquet Hall, Convention Center

[47.06] The MACHO Project: Exotic Microlensing from GMAN

M. Pratt, S. Marshall (CfPA/UCSB), C. Alcock, D. Alves, K. Cook, P. Purdue (LLNL), R. Allsman (ANUSF), D. Alves (UC Davis), T. Axelrod, K. Freeman, B. Peterson, A. Rodgers (MSSSO), T. Banks, T. Love, P. Yock (U. Canturbury), A. Becker, D. Reiss, C. Stubbs (CfPA/U Washington), D. Bennett (CfPA/LLNL), K. Griest, J. Guern, M. Lehner (CfPA/UCSD), D. Maoz (Tel Aviv U.), P. Quinn (ESO), W. Sutherland (Oxford), D. Welch (McMaster)

We present the results of the MACHO project alert system for 1995 and subsequent followup by GMAN (Global Microlensing Alert Network). Included in the 40+ events detected in real--time are two events that have exhibited significant deviations from the standard microlensing model of point--source and point--lens. In both cases, these deviations were detected prior to peak magnification. Observations took place at four sites on three continents in six independent passbands and were dynamically rescheduled within 24 hours throughout the events. Spectra have also been obtained near peak for both events. MACHO alert 95-12 appears to be microlensing by a binary lens and alert 95-30 is a spectacular example of lensing of a resolved source. The information available from these exotic events can provide additional constraints on the lensing system. In particular, 95-30 provides a measurement of the angular velocity of the lens thereby removing some of the degeneracy in determining the lens mass.

Program listing for Tuesday