GCN Circular 43195
Subject
GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
Event
Date
2025-12-23T01:14:18Z (2 days ago)
From
Giovanni Calapai at Calapai Astronomical Observatory, Massa S. Giorgio, Messina, Italy <giovannicalapai@tiscali.it>
Via
Web form
Giovanni Calapai at Calapai Astronomical Observatory, Massa S. Giorgio, (Messina) Italy
Member of: GRB/UAI Gamma Ray Burst Section of Unione Astrofili Italiani.
Report:
We observed the field of GRB 251222A detected by SVOM/ECLAIRs (Yang et al., GCN 43188) and Fermi Gamma-ray Burst Monitor (GCN 43186) with the 11 inches Schmidt-Cassegrain (Celestron 11) telescope F/D=6,3.
The observations were started at 2025-12-22 18:27:54 UT (approximately 1.37 hours after burst) stacking a sets of unfiltered CCD image. The observations were carried out with clear skies, good visibility conditions and light gusts of wind.
The OT was detected at the following position:
RA (J2000.0) 05h 08m 46.7s
Decl. (J2000.0) -07° 12' 48.4"
Photometry was obtained using nearby PanSTARRS stars as follows:
Observation Mid-Time T-T0 (hr) Exposure Filter Mag. Mag. err.
2025-12-22 18:56:55 UT 1.85 30x60s CR 18.70 +/- 0.09
Magnitude was calibrated with the nearby PanSTARRS stars converted using Lupton (2005) equations.
No correction for galactic dust extinction was applied.
Our observations are consistent with other already reported Palmerio et al. (GCN 43189); An et al. (GCN 43194).
The message may be cited.