TITLE: GCN CIRCULAR NUMBER: 34989 SUBJECT: GRB 231110A: GECAM detection DATE: 23/11/12 01:01:31 GMT FROM: Yue Wang Yue Wang, Shaoli Xiong, Yue Huang report on behalf of the GECAM team: GECAM-B was triggered in-flight by a long burst, GRB 231110A, at 2023-11-10T21:19:35.100 UTC (T0), which was also observed by Swift/BAT (GCN # 34977). According to the realtime alert data of GECAM-B, this burst mainly consists of a long pulse with a duration (T90) of about ~20 sec (20-1000 keV). The GECAM-B localization is consistent with the Swift/BAT team localization (trigger=1195733) within the error. The time-averaged spectrum of GECAM-B realtime data shows that it could be adequately fit by a cut-off power-law with a flux about 1.3E-6 erg/cm^2 in 20-1000 keV. We note that these results are based on realtime alert data and thus very preliminary. Refined analysis will be reported later. Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) mission originally consists of two microsatellites (GECAM-A and GECAM-B) launched in Dec. 2020. As the third member of GECAM constellation, GECAM-C was launched onboard SATech-01 experimental satellite in July 2022. GECAM mission is funded by the Chinese Academy of Sciences (CAS).