GCN Circular 34259
Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy) 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) Unione Astrofili Italiani (UAI) report: We imaged the field of GRB 230723B detected by SWIFT(trigger 1180410) with the telescope LX200 12” of GAD Observatory, La Spezia, Italy Member of: UAI/SSV - Unione Astrofili Italiani/sezione stelle variabili, GRB section. GAD - Gruppo Astronomia Digitale. The observations started 557 min after the GRB trigger, at the end of twilight, with a Shmidt-Cassegrain telescope D=304 mm with reducer F/D=4.75. Weather conditions were medium. We co-added 42 exposures of 120 sec each. Start T0+ End T0+ R lim 557 min 641 min 19 We did not found any optical counterpart in the error box of the XRT candidate. Page et al. GCN 34234 Magnitudes were estimated with the Gaia EDR3 cat. and are not corrected for galactic dust extinction. Reference: https://www.parcodellestelle.com/ The message may be cited.