--------------------------------------------- PLANET ANOMALY UPDATE 2004 #7-1 (issued 17-Jun, 14:30 UT) --------------------------------------------- Sudden and short caustic exit in OGLE 2004-BLG-250 Dear Colleagues, OGLE data collected until 17-Jun, 8:36 UT and PLANET data from the Danish 1.54m telescope at ESO LaSilla (Chile) until 17-Jun, 8:55 UT that was received after having issued PLANET anomaly alert 2004 #7, reveals that a data point previously believed to be on the rise to the caustic exit peak rather belongs to the falling part of the lightcurve after this peak but before the end of the caustic exit. This wrong assumption invalidates the previously obtained prediction of the caustic exit time. The combination of PLANET and OGLE data shows that the end of the caustic exit occured between HJD-2450000 = 3173.684 (17-Jun, 4:25 UT) and HJD-2450000 = 3173.747 (17-Jun, 5:55 UT). Despite the fact that most of the caustic exit was neither covered by PLANET observations from LaSilla nor by OGLE, we can restrict the caustic passage duration to be less than 16 hours. Unlike many other events, the caustic exit in OGLE 2004-BLG-250 was both short and sudden (i.e. it involved a short caustic rise time). The updated lightcurve, showing data from PLANET, OGLE, and MicroFUN, can be viewed as 'http://planet.iap.fr/PublicCurves/OB04250p.gif'. Event: OGLE 2004-BLG-250 RA (J2000): 18:07:20.51 Dec (J2000): -26:58:55.1 The baseline I magnitude reported by the OGLE team is 17.886. For more information, please consult: PLANET: http://planet.iap.fr/cuurentevents.html OGLE: http://www.astrouw.edu.pl/~ftp/ogle/ogle3/ews/blg-250.html MicroFUN: http://www.astronomy.ohio-state.edu/~microfun/Data/OB04250/ -------------- On behalf of the PLANET collaboration, Martin Dominik %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% If you prefer not to receive further PLANET Anomaly Alerts, please send an e-mail to planet@iap.fr.