GCN Circular 40973
Subject
GRB 250702F: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
Event
Date
2025-07-05T11:42:59Z (13 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 250702F detected by Swift/BAT (Klingler et al., GCN 40894) and Fermi/GBM (Fermi GBM Team, GCN 40892) with the 11 inches Schmidt-Cassegrain (Celestron 11) telescope F/D=6,3.
The observations were started at 2025-07-02 21:32:30 UT (approximately 0.43 hours after burst) stacking two consecutive sets of unfiltered CCD image. The observations were carried out with clear skies and good visibility conditions.
The OT was detected at the following position:
RA (J2000.0) 14h 11m 44.68s
Decl. (J2000.0) +16° 44' 55.0"
Photometry was obtained using nearby PanSTARRS stars as follows:
Observation Mid-Time T-T0 (hr) Exposure Filter Mag. Mag. err.
2025-07-02 22:03:02 UT 0.94 60x60s CR 17.13 +/-0.02
2025-07-02 23:05:09 UT 1.97 60x60s CR 18.07 +/-0.05
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 Jelinek et al. (GCN 40895); Kumar et al. (GCN 40896); Lipunov et al. (GCN 40898); Martin-Carrillo et al. (GCN 40900); Angulo et al. (GCN 40907); Becerra et al. (GCN 40911); Brivio et al. (GCN 40913); An et al. (GCN 40916); Dutton et al. (GCN 40921); Odeh et al. (GCN 40925); Moretti et al. (GCN 40926); Siegel et al. (GCN 40933); Ma et al. (GCN 40936); Vinko et al. (GCN 40939); Mohan et al. (GCN 40946); Ciabattari et al. (GCN 40968); Broens et al. (GCN 40969).
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