TITLE: GCN CIRCULAR NUMBER: 42267 SUBJECT: GRB 251013C: MarSEC, optical afterglow photometry DATE: 25/10/14 19:43:03 GMT FROM: I. Peretto at MarSEC (Marana Space Explorer Center) <ricerca@marsec.org> Ivo Peretto (MarSEC, Marana Space Explorer Center, Marana Di Crespadoro, VI, Italy) Member of: UAI/SSV - Unione Astrofili Italiani/Sezione Stelle Variabili, GRB section. AAVSO (American Association Variable Stars Observers). In a large collaboration with: M.G. Dainotti (National Astronomical Observatory of Japan), Y. Niino (Tokyo University, Institute of Astronomy), K. Kalinowski (Aarhus University, Department of Physics and Astronomy) and Stefano Lora, Giovanni Furlato and Giuseppe Peretto (MarSEC, Marana Space Explorer Center, Marana di Crespadoro, VI, Italy) report: We imaged the field of GRB 251013C detected by SVOM (Rakotondrainibe et al., GCN 42222), with the robotic telescope of (IAU station 565) with the telescope 14” RC Officine Stellari of MarSEC (Marana Space Explorer Center) with CCD Moravian G2-1600-MKII. The observations with a series of 90 sec exposures, 2025-10-13T23:13:26.703'UT of midpoint of exposure, with a Ritchey-Chretien telescope D=360 mm f/8. The afterglow was clearly detected at the following position: RA(J2000) = 23h 03m 20,7s Dec(J2000) = -00d 13' 37" We report our photometry analysis: HJD Rc Mag Err ------------------------------------- 2460962.4676701734 16.813 0.08 Weather conditions were good, sqm medium 20,85 We co-added 14 exposures of 90 sec. each. Magnitudes were estimated with the pan-STARRS cat and are derived using Lupton (2005) equations and are not corrected for galactic dust extinction. Reference: https://www.marsec.org/ The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/42267. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...