TITLE: GCN CIRCULAR NUMBER: 38343 SUBJECT: SVOM/GRM observation of GRB 241126B or a short burst from magnetar DATE: 24/11/27 12:23:43 GMT FROM: zhengchao_astro@foxmail.com

SVOM/GRM team: Chao Zheng, Shao-Lin Xiong, Shi-Jie Zheng, Chen-Wei Wang, Yong-Wei Dong, Jiang-Tao Liu, Jian-Chao Sun, Yue Huang, Jiang He, Min Gao, Hao-Xuan Guo, Lu Li, Yong-Ye Li, Hong-Wei Liu, Xin Liu, Hao-Li Shi, Li-Ming Song, You-Li Tuo, Wen-Long Zhang, Wen-Jun Tan, Hao-Xi Wang, Jin Wang, Jin-Zhou Wang, Ping Wang, Rui-Jie Wang, Yu-Xi Wang, Bo-Bing Wu, Jian-Ying Ye, Yi-Tao Yin, Wen-Hui Yu, Fan Zhang, Li Zhang, Peng Zhang, Shuang-Nan Zhang, Yan-Qiu Zhang, Yan-Ting Zhang, Shu-Min Zhao, Xiao-Yun Zhao (IHEP), Maria-Grazia Bernardini (LUPM/INAF-OAB), Laurent Bouchet (IRAP), David Corre (CEA), Tais Maiolino (LUPM), Frédéric Piron (LUPM), Stéphane Schanne (CEA), Jingwei Wang (IAP), JeanLuc Attéia (IRAP)

SVOM JSWG: Jian-Yan Wei (NAOC), Bertrand Cordier (CEA), Shuang-Nan Zhang (IHEP), Stéphane Basa (LAM), Arnaud Claret (CEA), Zi-Gao Dai (USTC), Frédéric Daigne (IAP), Jin-Song Deng (NAOC), Olivier Godet (IRAP), Andrea Goldwurm (APC), Diego Götz (CEA), Xu-Hui Han (NAOC), Cyril Lachaud (APC), En-Wei Liang (GXU), Yu-Lei Qiu (NAOC), Susanna Vergani (Obs.Paris), Jing Wang (NAOC), Chao Wu (NAOC), Li-Ping Xin (NAOC), Shao-Lin Xiong (IHEP), Bing Zhang (UNLV)

report on behalf of the SVOM team:

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)

View this GCN Circular online at https://gcn.nasa.gov/circulars/38343. --- To unsubscribe, open this link in a web browser: https://gcn.nasa.gov/unsubscribe/eyJhbGciOiJIUzI1NiJ9.eyJlbWFpbCI6InZzbmV0LW...