TITLE: GCN CIRCULAR NUMBER: 35401 SUBJECT: GRB 231216A: GAD Observatory, La Spezia, Italy upper limit DATE: 23/12/19 11:33:18 GMT FROM: Claudio Lopresti <cl3lop@gmail.com> Claudio Lopresti (Gruppo Astronomia Digitale - GAD Observatory, La Spezia, Italy) Member of: UAI/SSV - Unione Astrofili Italiani/Sezione Stelle Variabili, GRB section. GAD - Gruppo Astronomia Digitale. 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 231216A detected by SWIFT(trigger 1202749) with the telescope LX200 12” of GAD Observatory, La Spezia, Italy The observations with a series of 60 sec exposures started at 2023-12-16 23:14:43 UT, 261 min. after the GRB trigger,with a Shmidt-Cassegrain telescope D=304 mm with reducer F/D=4.75. at the following position (+/- 2 arcsec): RA (J2000): 02 39 05.45 Dec(J2000): +33 34 35.0 scope D=300 mm F/D=4.8. Weather conditions were medium. We co-added 75 exposures of 60 sec each. Start T0+ End T0+ R lim 261 min 341 min 18 We did not found any optical counterpart in 02 39 05.45 +33 34 35.0 position and in the error box of the XRT candidate. ref.: T. Sbarrato et al. GCN 35378 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. View this GCN Circular online at https://gcn.nasa.gov/circulars/35401. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...