TITLE: GCN CIRCULAR NUMBER: 40303 SUBJECT: GRB 250430A: Bassano Bresciano Observatory upper limit DATE: 25/05/01 13:33:33 GMT FROM: Ulisse Quadri at Bassano Bresciano Observatory <osservatoriobassano@gmail.com> U.Quadri, L.Strabla and P.Madurini (Bassano Bresciano Astronomical Observatory) Members of: GRB/UAI - Gamma ray Burst section of Unione Astrofili Italiani. AAVSO - American Association of Variable Star Observers. GAC - Gruppo Astrofili Cremonesi. 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), B. De Simone (Universita' degli Studi Di Salerno) report: We imaged the field of GRB 250430A detected by Swift with the robotic telescope of (IAU station 565) Bassano Bresciano Observatory, Italy. The observations started 5h 01m after the GRB trigger with our Newton telescope D=250 mm F/D=4.8. We co-added 2 series of 150 exposures of 30 sec each. Start T0+ End T0+ Rc lim. Err. 5h 01m 6h 30m 20.3 +/- 0.2 6h 31m 8h 01m 20.3 +/- 0.2 We did not found any optical uncatalogued object within the Swift error circle. Our upper limit is consistent with other observations reported by K. S. Kawabata et al. (GCN Circular 40294), Mohammad Odeh et al. (GCN Circular 40295), Andrea Saccardi et al (GCN Circular 40301), H. Hagio et al. (GCN Circular 40302). Magnitudes were estimated with the pan-STARRS cat and are derived using Lupton (2005) equations. Not corrected for galactic dust extinction. Reference: http://www.osservatoriobassano.altervista.org The message may be cited. View this GCN Circular online at https://gcn.nasa.gov/circulars/40303. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...