TITLE: GCN CIRCULAR NUMBER: 37642 SUBJECT: GRB 240929A : Leavitt Observatory optical upper limit DATE: 24/09/30 19:52:37 GMT FROM: leavittob@gmail.com L. Moretti and E. Pavoni (Leavitt Observatory, Italy), Members of: GRB/UAI - Gamma ray Burst section of Unione Astrofili Italiani. ATA - Associazione Tuscolana di Astronomia. 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 240929A detected by INTEGRAL (Fermi GBM Team, GCN 37627; Lipunov et al., GCN 37628; Preis et al., GCN 37629; Mereghetti et al., GCN 37630), with the RC telescope (D=250 mm, F/D=8) of Leavitt Observatory, Italy. The observations started at 20:17:40 UT on 2024-09-29, i.e. about 27 min. after the INTEGRAL trigger, at the following position: RA(J2000) = 00h 09m 42s Dec(J2000) = 74° 49' 39" Weather conditions were good. We co-added 27 exposures of 120 sec each (total 54 min). We did not found any optical counterpart in the error box (2 arcmin) of INTEGRAL, with the following upper limit: Start End Limit 2024-09-29T20:17:40 2024-09-29T21:10:53 > 20.9 Magnitudes were estimated with the BP-band of Gaia DR3 catalogue (*) and are not corrected for galactic dust extinction. Reference: https://leavittobservatory.altervista.org The message may be cited. (*) https://gea.esac.esa.int/archive/documentation/GEDR3/Data_processing/chap_cu... View this GCN Circular online at https://gcn.nasa.gov/circulars/37642. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...