From planet Wed Jun 17 20:34:10 1998
Subject: PLANET ANOMALY ALERT: 98-SMC-01 Caustic Crossing!!
To: CausticMailingList
Date: Wed, 17 Jun 1998 20:34:10 +0200 ()
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Dear Colleagues,

Improved PLANET data reduction and point source modeling now indicate that 
the SMC microlensing event MACHO 98-SMC-01 is likely to 
undergo a second caustic crossing near JD - 2450000 = 982.5, that is, 
June 18 00:00 (UT) (ie, midnight June 17/18 Greenwich time).  
This is earlier than the center of the current MACHO errorbox of 
19.2 +/- 1.5 June 1998 for this crossing, but lies inside their 
quoted uncertainties.   

Immediate monitoring is essential, since source resolution effects 
near a caustic peak may be used to determine the proper motion of 
the lens, perhaps constraining whether the lens lies in the SMC 
or in the halo of the Milky Way.
 
Event:           MS-98-001      (MACHO 98-SMC-01)
RA  (J2000):     00:45:35.2
Dec (J2000):    -72:52:34

Baseline MACHO V magnitude reported by MACHO team to be 21.8.
The current magnification is larger than 20.

Finding charts and updated information can be found on the 
PLANET web page at:  http://www.astro.rug.nl/~planet.

MACHO information on the same event can be found at the MACHO alert 
web page at:  http://darkstar.astro.washington.edu