TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2324 SUBJECT: GRB030725, possible optical transient DATE: 03/07/26 02:27:14 GMT FROM: Arne A. Henden at USNO/USRA Berto Monard of Bronberg Observatory, Pretoria South Africa reports, on behalf of the AAVSO International High Energy Network, the possible detection of an optical transient to GRB030725 (=H2779; Shirasaki et al., GCN 2322). The location of the OT is estimated to be (J2000) RA: 20 33 59.49 Dec: -50 40 56.0 The OT shows a fading behavior (starting 7.1hrs after burst): GRB030725 030725.788 18.8 Unfiltered with a red zeropoint GRB030725 030725.848 19.0 Unfiltered with a red zeropoint GRB030725 030725.938 19.6 Unfiltered with a red zeropoint Objects from the UCAC1 catalog were used for photometry and astrometry. The FTS images will be posted shortly to ftp.aavso.org in the grb/GRB030725 directory. More details on the observation are below: Contact name: Berto Monard Contact e-mail: bmonard@mweb.co.za Observer: Berto Monard / MLF Site Name: Bronberg Observatory / CBA Pretoria Nearest town: Pretoria / South Africa Site latitude: 25deg 55min South Site longitude: 28deg 27min East Site elevation: 1590m Telescope type: SCT / 30cm Telescope focal ratio: f/4.2 effectively CCD camera: SBIG ST-7E CCD detector: KAF-0401E CCD dimensions: 765x510 pixels CCD pixel scale: 1.52 arcsec/pixel F.O.V: 18 arcmin E-W x 12.5 arcmin N-S GRB object name: GRB 030725 Observation date: 20030725 UT Observation midpoint time: 18 55 UT and 20 02 UT Exposure time per frame: 45 sec Number of stacked frames: 15 respectively 8 Filters used: unfiltered / CR Processed: FF, DS, stacked Estimated seeing: 3.0 arcsec FWHM Limiting magnitude: 20.5CR estimated Sky conditions: clear, fair seeing Details of observations: a follow up on the previous report The AAVSO International GRB network is greatful for a generous grant from the Curry Foundation and to NASA for the financial support for the High Energy Workshops for Amateur Astronomers.