GCN Circular 2324
Subject
GRB030725, possible optical transient
Date
2003-07-26T02:27:14Z (21 years ago)
From
Arne A. Henden at USNO/USRA <aah@nofs.navy.mil>
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.