SVOM/GRM observation of GRB 241126B or a short burst from magnetar

During the commissioning phase, SVOM/GRM was triggered (trigger reference: sb24112602) in-flight by a short burst at 2024-11-26T17:58:15.000 UT (T0). With the event-by-event data downloaded through the X-band ground station, the GRM light curve shows that this burst consists of multiple pulses with a duration of about 0.09 s. No significant signal could be observed above 70 keV (deposit energy) from the multiple energy band light curves. The SVOM/GRM light curve can be found here: https://www.bursthub.cn//admin/static/svgrb241126B.png We tentatively name this burst as GRB 241126B, as we note that there is a similar short burst detected by GECAM-B (C. Zheng et al., GCN 38326) and SVOM/GRM (C. Zheng et al., GCN 38327) around 2024-11-26T05:12:17, which was suggested to probably originate from SGR 1830-0645 based on the localization provided by GECAM-B (C. Zheng et al., GCN 38326). Considering the observed features (short duration, soft spectrum, location) of GRB 241126B, and the short time interval between these two bursts, we suggest that GRB 241126B is also likely from SGR 1830-0645. The Space Variable Objects Monitor (SVOM) is a China-France joint mission led by the Chinese National Space Administration (CNSA, China), the National Center for Space Studies (CNES, France), and the Chinese Academy of Sciences (CAS, China), which is dedicated to observing gamma-ray bursts and other transient phenomena in the energetic universe. GRM is developed by the Institute of High Energy Physics (IHEP) of CAS. The SVOM/GRM point of contact for this burst is: Chao Zheng (IHEP)(zhengchao97@ihep.ac.cn)