GCN Circular 1894
Subject
Possible break in the GRB 030226 light curve
Event
Date
2003-02-27T08:55:44Z (22 years ago)
From
Jochen Greiner at MPI <jcg@mpe.mpg.de>
J. Greiner (MPE Garching),
C. Ries, H. Barwig (Uni. Munich),
J. Fynbo (Uni Aarhus),
S. Klose (TLS Tautenburg),
on behalf of the GRACE collaboration
report:
We observed the afterglow of the HETE burst (H10893; Suzuki et al., GCN 1888)
GRB 030226 (Fox et al., GCN 1879; Price et al., GCN 1880) in the R band
with the EMMI and SUSI instruments at the NTT (La Silla, ESO) and the MONICA
imager at the Wendelstein 0.8 m telescope (Germany). We calibrated against
the USNO-B R2 magnitudes of 5 surrounding stars which provides basically
the same calibration as that given for stars A and B by Garnavich et al.
(GCN 1885; R=15.39 +/-0.05 and R=17.06 +/-0.05, respectively). A preliminary
reduction gives the following magnitudes:
Start time exposure OT star A star B
NTT/EMMI Feb 26 08:27 3x300 s 18.80+-0.07 15.40+-0.05 17.05+-0.05
Wendelstein Feb 26 19:04 2x600 s 19.87+-0.10 15.47+-0.08 17.05+-0.10
Wendelstein Feb 27 03:12 600 s 20.60+-0.13 15.42+-0.08 17.04+-0.10
Wendelstein Feb 27 03:23 600 s 20.74+-0.13 15.43+-0.08 17.05+-0.10
NTT/SUSI Feb 27 05:25 3x180 s 21.00+-0.20 15.47+-0.10 ---
We confirm the decay slope of -0.88 as communicated by Price & Warren
(GCN 1890) until about 0.8 days after the GRB. Thereafter, the brightness
seems to drop significantly faster. A light curve plot will be available
at http://www.mpe.mpg.de/~jcg/grb030226.html. Further monitoring is strongly
encouraged.
We are grateful for the assistence of the staff at La Silla and Wendelstein.