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:
This message is citeable."