TITLE: GCN CIRCULAR NUMBER: 35672 SUBJECT: GRB 240204A: Montarrenti Observatory optical observations DATE: 24/02/04 23:54:13 GMT FROM: Simone Leonini at Montarrenti Observatory (Siena, Italy) <s.leonini@iol.it> S. Leonini, M. Conti, P. Rosi, L.M. Tinjaca Ramirez, L. Bellizzi (Montarrenti Observatory, Siena, Italy, part of UAI/SSV-GRB section), 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 B. De Simone (Universita' degli Studi Di Salerno) report: We observed the field of GRB 240204A (Swift triggered on the Fermi/GBM, GCN 35664; Cenko et al., GCN 35666; Pozanenko et al., GCN 35670) with the automated and remoted 0.53m Ritchey-Chretien telescope at Montarrenti Observatory (Siena, Italy, IAU code C88). The observations were started under good weather conditions at 2024-02-04 18:58:44 UT (approximately 4 hours after burst) stacking 30x40s Rc-band CCD images. The OT was detected at the following position: RA (J2000.0) 06h 56m 43.39s +/-0.11 Decl. (J2000.0) +01° 01' 38.5" +/-0.14 Preliminary photometry was obtained using nearby PanSTARRS stars as follows: MJD Filter Mag. Err. 60345.30597 Rc 21.02 +/-0.21 Magnitudes were converted using Lupton (2005) equations and were not corrected for galactic dust extinction. View this GCN Circular online at https://gcn.nasa.gov/circulars/35672. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...