Astronomy and Astrophysics – Astrophysics
Scientific paper
1998-07-09
Astronomy and Astrophysics
Astrophysics
Light curve data at http://www.astro.rug.nl/~planet/planetpapers.html ApJ, in press
Scientific paper
We present photometric and spectroscopic data for the second microlensing event seen toward the Small Magellanic Cloud (SMC), MACHO-98-SMC-1. The lens is a binary. We resolve the caustic crossing and find that the source took 2 Delta t = 8.5 hours to transit the caustic. We measure the source temperature T_eff=8000 K both spectroscopically and from the color (V-I)_0~0.22. We find two acceptable binary-lens models. In the first, the source crosses the caustic at phi=43.2 deg and the unmagnified source magnitude is I_s=22.15. The angle implies that the lens crosses the source radius in time t_* = Delta t sin phi = 2.92 hours. The magnitude (together with the temperature) implies that the angular radius of the source is theta_* = 0.089 micro-arsec. Hence, the proper motion is mu=theta_*/t_*=1.26 km/s/kpc. For the second solution, the corresponding parameters are phi=30.6 deg, I_s=21.81, t_*=2.15 hours, theta_* = 0.104 micro-asrsec, mu=2.00 km/s/kpc. Both proper-motion estimates are slower than 99.5% of the proper motions expected for halo lenses. Both are consistent with an ordinary binary lens moving at ~ 75-120 km/s within the SMC itself. We conclude that the lens is most likely in the SMC proper.
Albrow Michael D.
Beaulieu2 J.-P.
Caldwell John A. R.
DePoy Darren L.
Dominik Martin
No associations
LandOfFree
The Relative Lens-Source Proper Motion in MACHO 98-SMC-1 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The Relative Lens-Source Proper Motion in MACHO 98-SMC-1, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The Relative Lens-Source Proper Motion in MACHO 98-SMC-1 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-297216