TITLE: GCN CIRCULAR NUMBER: 40209 SUBJECT: GRB 250419A: Calapai Observatory, Massa S. Giorgio (Messina), optical observations. DATE: 25/04/22 15:45:12 GMT FROM: Giovanni Calapai at Calapai Astronomical Observatory, Massa S. Giorgio, Messina, Italy <giovannicalapai@tiscali.it> 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 250419A detected by SVOM/ECLAIRs (Wang et al. GCN 40168) with the 11 inches Schmidt-Cassegrain (Celestron 11) telescope F/D=6,3. The observations were started at 2025-04-19 23:55 UT (approximately 21.43 hours after burst) stacking a set 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) 13h 29m 37.33s Decl. (J2000.0) +07° 02' 27.5" Photometry was obtained using nearby PanSTARRS stars as follows: Observation Mid-Time T-T0 (hr) Exposure Filter Mag. Err. 2025-04-20 01:19:29 UT 22.83 164x60s CR 19.76 +/-0.06 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 López et al. (GCN 40169), Xin et al. (GCN 40170), Zheng et al. (GCN 40171), Kumar et al. (GCN 40172), Lipunov et al. (GCN 40179), Odeh et al. (GCN 40180), Perley & Bochenek (GCN 40181), Pankov et al. (GCN 40182), Pérez-Fournon et al. (GCN 40183), Kuin (GCN 40185), Wu et al. (GCN 40186), Xie et al. (GCN 40187), Jiang et al. (GCN 40188), Ghosh et al. (GCN 40189), Bochenek & Perley (GCN 40190), Pankov et al. (GCN 40202), Masi (GCN 40206). The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/40209. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...