TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2228 SUBJECT: HETE GRB030329, correction to Rc Observations in Loiano DATE: 03/05/13 18:01:31 GMT FROM: Graziella Pizzichini at IASF/CNR,Bologna G. Pizzichini and P. Ferrero (IASF/CNR, Bologna), C. Bartolini, A. Guarnieri, A. Piccioni (Bologna University), A. Righini (Firenze University) and I. Bruni (Bologna Astronomical Observatory) report: The Rc magnitude quoted by us for the OT of GRB030329 in GCN 2136 was not correct, due to a bad subtraction of the background in conditions of nearly full moon. By coadding the three exposures listed below: -- UT start exptime filter ----------------------------- Apr. 13.8783 300s Rc Apr. 13.8824 300s Rc Apr. 13.8865 300s Rc and using the star at RA = 161.231899, DEC = 21.522793, in the new field photometry given by Henden, GCN 2082, we now find Rc = 19.53 +- 0.20 . In the following night, by coadding the exposures: - UT start exptime filter ----------------------------- Apr. 14.8879 300s Rc Apr. 14.8923 300s Rc Apr. 14.8973 300s Rc and still under very unfavorable conditions because of the moon, we find Rc = 20.27 +- 0.33. Errors quoted are 1 sigma. We thank Dr. A. Henden for promptly signalling the problem to us and Dr. E. Palazzi for useful advice.