TITLE: GCN CIRCULAR NUMBER: 36221 SUBJECT: GRB240421B: Zadko Observations DATE: 24/04/22 02:30:22 GMT FROM: Bruce Gendre at UWA bruce.gendre@gmail.com
B. Gendre, E. Moore, F. Panther, D. Coward, J. A. Moore (OzGrav-UWA), and A. Klotz (IRAP-CNRS-OMP), report:
We imaged the field of GRB 240421B detected by SWIFT (trigger 1223470) with the Zadko robotic telescope (D=100cm) located at the observatory - Gingin, Australia.
The observations started 7.97h after the GRB trigger. The elevation of the field increased from 25 degrees above horizon and weather conditions were good.
The date of trigger : t0 = 2024-04-21T09:42:54.050
The first image is 60.0s exposure in tracking mode: t0+28754.8s to t0+28814.8s : R > 16.2
We co-added a series of exposures: t0+28754.8s to t0+29599.3s : R > 17.7
Magnitudes were estimated with the nearby USNO-B1 stars and are not corrected for galactic dust extinction.
N.B. Galactic coordinates are lon= 26.7039 lat=-21.4736 and the galactic extinction in R band is 0.7 magnitudes estimated from D. Schlegel et al. 1998ApJ...500..525S.
This message may be cited.
View this GCN Circular online at https://gcn.nasa.gov/circulars/36221. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...