TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  32
SUBJECT: GRB980326 optical observations
DATE:    98/03/28 17:56:00 GMT
FROM:    Paul Groot at U. of Amsterdam  <paulgr@astro.uva.nl>


P.J. Groot, P.M. Vreeswijk, T.J. Galama (University of Amsterdam); 
E. Pian, F. Frontera, E. Palazzi (CNR, Bologna); M. Feroci (CNR, Roma);
C. Kouveliotou and C. Robinson (USRA at NASA/MSFC) on behalf of the 
CTIO GRB collaboration; J. van Paradijs (U of Amsterdam and
U of Alabama in Huntsville); C. Tinney, Phillips, Driver, Smith,
Jones, Windridge (AAO); M. Keane, P. Hall, M. Smith (NOAO at CTIO);
J.F. Gonzalez, C. Lidman (ESO) report:
"Comparison of optical R-band observations of the error box of 
GRB980326 (IAUC 6851) taken at the AAT at Mar 27.42 UT (480s), 
the CTIO 4m-telescope at Mar 28.04 UT (600s) and the 
ESO 3.5m NTT at Mar 28.01 UT (ESO1, 600s) and Mar 28.17 UT 
(ESO2, 600s) shows a clearly variable object located at RA 08:36:34.28, 
Decl -18:51:23.9 (J2000).  Differential photometry with respect
to three local stars shows a decrease between the AAT and ESO1 
of 1.2(1) mag, AAT and CTIO of 1.6(1) mag and AAT and ESO2 of 1.7(1) mag. 
The three local standards have coordinate end-figures: 1) 36:35.41, 51:41.6; 
2) 36:31.00, 51:17.3; 3) 36:34.03, 50:53.2.  Their R-band magnitudes are: 
1) 18.4(1); 2) 21.7(1); 3) 20.3(1), as determined with respect to 
Landolt SA 98, no. 626, 624, 634, 590.  At the time of the AAT observation 
(Mar. 27.42 UT) the R-band magnitude of the variable was R=21.7, 
equal to that of comparison star 2. 
A finding chart of the variable can be found at:
http://www.astro.uva.nl/paulgr/grb/grb980326.html.

This message is citeable."