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GCN Circular 2056

Subject
GRB 030329: optical observations
Date
2003-04-01T02:11:50Z (21 years ago)
From
Jerome A. Orosz at San Diego State U <orosz@zwartgat.sdsu.edu>
J. Brodney Fitzgerald and Jerome A. Orosz (San Diego 
State University) report:

We have observed the field of GRB 030329 (Peterson & Price, GCN 1985)
with the 1 meter telescope at the Mount Laguna Observatory (located 45
miles east of downtown San Diego at a dark site in the Cleveland
National Forest at an altitude of 6100 feet or 1859 meters) on the
nights of 2003 March 30 and 31 (UT).  We used a Loral 2048 x 2048 CCD
(binned 2 x 2) and Bessell B, V, R, and I filters.  Both nights were
photometric.  The instrumental time series were obtained using
Stetson's programs DAOPHOT, ALLSTAR, and DAOMASTER.  The instrumental
magnitudes were placed on the standard scales using Hendon's (GCN
2023) calibration.  Our observations are summarized in the 4 tables
below.  The errors quote include only the DAOPHOT errors, and do not
include errors in the zero points (estimated to be a few percent).
The CCD images of the GRB field and some Landolt fields are available
upon request to orosz@sciences.sdsu.edu.  Further observations are
planned for the night of April 1 (UT).

We also report the discovery of a possible eclipsing binary in the
field.  The J2000 coordinates are 10:44:36.81, +21:26:58.8 (taken from
Hendon's list given in GCN 2023).  The star was at a minimum
brightness around March 31 at 4:30 UT.  Over the next three hours it
brightened by about 0.6 magnitudes in all the filters.  The brightness
level was roughly constant between about 8:10 UT and 11:00 UT.  The
star was apparently constant on the night of March 30, although this
conclusion is somewhat weak owing to the fact that it was saturated in
many of our images.  The following table gives the extreme magnitudes
observed:

Filter    Min Mag    Max Mag
-----------------------------
  B        14.36      13.77
  V        14.00      13.41
  R        13.78      13.11
  I        13.60      13.00

Our GRB observations follow: 

Table 1:  B Observations:

  date-obs at start     exptime     mag      err
                         (sec)                  
-------------------------------------------------
2003-03-30T04:39:56.10  600.000    16.263   0.008
2003-03-30T05:19:08.50  480.000    16.321   0.010
2003-03-30T06:21:03.50  480.000    16.415   0.006
2003-03-30T07:24:03.20  480.000    16.510   0.004
2003-03-30T08:01:23.30  480.000    16.577   0.004
2003-03-30T08:50:07.70  480.000    16.648   0.004
2003-03-30T09:38:09.20  480.000    16.712   0.005
2003-03-30T10:38:02.00  480.000    16.889   0.013
2003-03-31T03:49:47.10  240.000    17.060   0.008
2003-03-31T04:09:46.30  240.000    17.087   0.009
2003-03-31T04:53:02.80  300.000    17.112   0.008
2003-03-31T05:16:57.30  300.000    17.140   0.008
2003-03-31T05:39:42.70  300.000    17.172   0.008
2003-03-31T06:17:01.30  300.000    17.191   0.008
2003-03-31T06:41:33.10  300.000    17.239   0.006
2003-03-31T07:17:46.30  300.000    17.246   0.009
2003-03-31T07:40:25.90  300.000    17.243   0.007
2003-03-31T08:03:53.90  300.000    17.285   0.009
2003-03-31T08:09:22.40  300.000    17.293   0.008
2003-03-31T08:48:31.90  300.000    17.296   0.007
2003-03-31T09:10:50.10  300.000    17.309   0.007
2003-03-31T09:33:07.30  300.000    17.327   0.007
2003-03-31T09:55:57.70  300.000    17.361   0.010
2003-03-31T10:42:17.30  300.000    17.374   0.012
2003-03-31T11:05:04.70  300.000    17.385   0.014


Table 2:  V Observations:

  date-obs at start      exptime     mag     err
                          (sec)                  
-------------------------------------------------
2003-03-30T04:39:56.10   600.000   15.8732  0.011
2003-03-30T05:19:08.50   480.000   15.9492  0.007
2003-03-30T06:21:03.50   480.000   16.0532  0.007
2003-03-30T07:24:03.20   480.000   16.1452  0.004
2003-03-30T08:01:23.30   480.000   16.1642  0.041
2003-03-30T08:50:07.70   480.000   16.2722  0.004
2003-03-30T09:38:09.20   480.000   16.3632  0.005
2003-03-30T10:38:02.00   480.000   16.4142  0.007
2003-03-31T03:54:27.10   240.000   16.6532  0.006
2003-03-31T04:15:22.50   240.000   16.6672  0.011
2003-03-31T04:59:11.40   300.000   16.7222  0.006
2003-03-31T05:22:35.30   300.000   16.7522  0.007
2003-03-31T05:45:20.50   300.000   16.7572  0.008
2003-03-31T06:23:02.00   300.000   16.7942  0.006
2003-03-31T06:47:19.40   300.000   16.8242  0.007
2003-03-31T07:23:20.20   300.000   16.8622  0.006
2003-03-31T07:46:01.50   300.000   16.8722  0.006
2003-03-31T08:14:56.30   300.000   16.8802  0.007
2003-03-31T08:20:24.00   300.000   16.8702  0.007
2003-03-31T08:54:07.40   300.000   16.9002  0.006
2003-03-31T09:16:24.00   300.000   16.9002  0.007
2003-03-31T09:38:42.50   300.000   16.9172  0.007
2003-03-31T10:01:27.30   300.000   16.9292  0.008
2003-03-31T10:06:57.80   300.000   16.4682  0.010
2003-03-31T10:12:26.00   300.000   16.9592  0.009
2003-03-31T10:48:07.50   300.000   16.9402  0.012
2003-03-31T11:10:40.10   300.000   16.9662  0.014


Table 3:  R Observations:

  date-obs at start      exptime    mag    err
                          (sec)                  
-------------------------------------------------
2003-03-30T04:39:56.10   600.000  15.402  0.006
2003-03-30T05:19:08.50   480.000  15.524  0.007
2003-03-30T06:21:03.50   480.000  15.694  0.009
2003-03-30T07:24:03.20   480.000  15.801  0.004
2003-03-30T08:01:23.30   480.000  15.841  0.005
2003-03-30T08:50:07.70   480.000  15.917  0.004
2003-03-30T09:38:09.20   480.000  16.004  0.006
2003-03-30T10:38:02.00   480.000  16.048  0.006
2003-03-31T03:59:42.40   240.000  16.277  0.009
2003-03-31T04:20:13.10   240.000  16.313  0.024
2003-03-31T05:04:46.90   300.000  16.356  0.006
2003-03-31T05:28:31.20   300.000  16.378  0.005
2003-03-31T05:50:50.80   300.000  16.392  0.007
2003-03-31T06:29:05.50   300.000  16.421  0.006
2003-03-31T06:52:51.60   300.000  16.459  0.005
2003-03-31T07:28:53.20   300.000  16.479  0.006
2003-03-31T07:51:53.40   300.000  16.487  0.007
2003-03-31T08:26:10.70   300.000  16.516  0.022
2003-03-31T08:31:42.00   300.000  16.509  0.006
2003-03-31T08:59:40.10   300.000  16.536  0.007
2003-03-31T09:21:55.50   300.000  16.535  0.006
2003-03-31T09:44:13.50   300.000  16.539  0.008
2003-03-31T10:18:09.40   300.000  16.560  0.007
2003-03-31T10:29:22.00   300.000  16.555  0.009
2003-03-31T10:53:41.70   300.000  16.577  0.007
2003-03-31T11:16:11.50   300.000  16.583  0.015


Table 4:  I Observations:

  date-obs at start      exptime    mag      err
                          (sec)                  
-------------------------------------------------
2003-03-30T04:39:56.10   600.000  15.0006   0.009
2003-03-30T05:19:08.50   480.000  15.1076   0.012
2003-03-30T06:21:03.50   480.000  15.2816   0.007
2003-03-30T07:24:03.20   480.000  15.3916   0.004
2003-03-30T08:01:23.30   480.000  15.4266   0.027
2003-03-30T08:50:07.70   480.000  15.5186   0.005
2003-03-30T09:38:09.20   480.000  15.6376   0.008
2003-03-30T10:38:02.00   480.000  15.7036   0.011
2003-03-31T04:04:32.10   240.000  15.8716   0.008
2003-03-31T04:25:02.80   240.000  15.8926   0.010
2003-03-31T05:10:34.50   300.000  15.9396   0.006
2003-03-31T05:34:03.50   300.000  15.9596   0.006
2003-03-31T05:56:25.90   300.000  15.9946   0.006
2003-03-31T06:35:53.60   300.000  16.0276   0.007
2003-03-31T06:58:26.10   300.000  16.0536   0.006
2003-03-31T07:34:51.90   300.000  16.0826   0.008
2003-03-31T07:58:11.70   300.000  16.0746   0.008
2003-03-31T08:37:12.10   300.000  16.0836   0.008
2003-03-31T08:42:40.70   300.000  16.1066   0.006
2003-03-31T09:05:09.40   300.000  16.1026   0.007
2003-03-31T09:27:28.10   300.000  16.1196   0.008
2003-03-31T09:49:53.50   300.000  16.1346   0.009
2003-03-31T10:23:41.20   300.000  16.1386   0.009
2003-03-31T10:35:00.70   300.000  16.1716   0.013
2003-03-31T10:59:14.40   300.000  16.1476   0.012
2003-03-31T11:21:45.60   300.000  16.1626   0.019

References:

Hendon, A., et al. 2003, GCN 2023
Landolt, A. U. 1992, AJ, 104, 340
Peterson, B, A. & Price, P. 2003, GCN 1985
Stetson, P. B. 1987, PASP, 99, 191
 


-------------------------------------------------------------------------
                             Jerome A. Orosz
      Assistant Professor of Astronomy, San Diego State University
             5500 Campanile Drive, San Diego, CA 92182-1221
(619) 594-7118 (office), 594-6182 (dept. secretary), 594-1413 (dept. fax) 
               http://mintaka.sdsu.edu/faculty/orosz/web/
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