{
  "bibcode": "2021GCN.29990....1C",
  "body": "C. Cai, S. L. Xie, Y. Huang, S. L. Xiong, S. Xiao, Y. Zhao, J. C. Liu,\nC. Y. Li, Y. Q. Zhang, W. C. Xue, C. Zheng, Z. W. Guo, X. Y. Zhao,\nZ. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He,\nB. Li, C. Li, J. H. Li, Q. X. Li, X. B. Li, X. Q. Li, Y. G. Li, X. H. Liang,\nJ. Y. Liao, J. C. Liu, X. J. Liu, Y. Q. Liu, F. J. Lu, Q. Luo, X. Ma,\nG. Ou, W. X. Peng, R. Qiao, D. L. Shi, J. Y. Shi, L. M. Song,\nX. Y. Song, G. X. Sun, X. L. Sun, Y. L. Tuo, C. W. Wang, J. Z. Wang,\nP. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, Q. B. Yi,\nB. X. Zhang, C. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang,\nK. Zhang, P. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao,  S. J. Zheng,\nX. Zhou (IHEP), report on behalf of GECAM team:\n\nDuring the commissioning phase, GECAM-B was triggered by a long GRB 210511B\nat 2021-05-11T11:26:40.600 UTC (denoted as T0), \nwhich was also observed by Fermi/GBM (GCN #29988).\n\nGECAM alert data was promptly downlinked to the ground through the\nshort message service of BeiDou Navigation Satellite System (BDS).\nThe time latency of the first BeiDou message relative to the trigger time\nis about 1 minute.\n\nAccording to the BDS alert data, this burst mainly consists of \na single pulse with a duration of about 10s.  \n\nAn automatic on-ground localization was calculated using the light curves\nand spectrum. Although the in-flight calibration of energy response and\nlocalization has not been finalized yet, GECAM-B localized this burst to\nthe following position (J2000):\nra: 317.99 deg\ndec: 59.53 deg\nerr: 3.19 deg (statistical only)\nThe current systematic error of location is estimated to be several degrees\nwhich could be minimized by the ongoing calibration. This position is \nconsistent with the Fermi GBM team localization (GCN 29988) within the error.\n\nThe GECAM light curve could be found here:\nhttp://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_lc_grd_all_combine_74431600.png\n\nAs the detailed science data are downloaded, all analyses would be improved.\n\nPlease note that all GECAM results here are preliminary. The final analysis\nwill be published in journal papers or GECAM online catalog.\n\nGravitational wave high-energy Electromagnetic Counterpart All-sky Monitor\n(GECAM) mission consists of two small satellites (GECAM-A and GECAM-B) in\nLow Earth Orbit (600 km, 29 deg), launched on Dec 10, 2020 (Beijing Time),\nwhich was funded by the Chinese Academy of Sciences (CAS).",
  "circularId": 29990,
  "createdOn": 1620744620000,
  "email": "caice@ihep.ac.cn",
  "subject": "GRB 210511B: GECAM detection",
  "submitter": "Ce Cai at IHEP  <caice@ihep.ac.cn>",
  "eventId": "GRB 210511B"
}