GRB 241002C : Detection of a long soft transient by SVOM/ECLAIRs

Report on behalf of the SVOM team: During the commissioning phase, the SVOM/ECLAIRs telescope triggered and located a long soft transient, labelled GRB 241002C (sbsb24100203) at 2024-10-02T09:20:48 UT (Tb). The following trigger information was received on the ground with low-latency by the SVOM VHF Alert Network. The burst was detected by the Image Trigger (IMT) which sent 3 Alerts in the 5-8 keV energy band. The best Alert has a signal-to-noise ratio of 8.9 over a time window of 655.36 s starting at Tb. The image transmitted shows a clean point-like source. The event location is RA, Dec = 62.45, -7.91 (J2000) (or L, B = 159.79, -39.36). The statistical uncertainty on this position is 9.5 arcminutes, to which we recommend adding 10 arcminutes of systematic uncertainty in quadrature. SVOM did not slew to the burst since automated slewing was not enabled. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA), French Space Agency (CNES), and the Chinese Academy of Sciences (CAS), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. ECLAIRs was developed jointly by APC, CEA, CNES, and IRAP. The SVOM point of contact for this burst is: b.cordier AT cea.fr.