{
  "bibcode": "2021GCN.30070....1L",
  "body": "C. Y. Li, S. Xiao, S. L. Xiong, X. Y. Zhao, X. Y. Song, Y. Huang,\nC. Cai, Y. Zhao, Q. B. Yi, J. C. Liu, Y. Q. Zhang, W. C. Xue, C. Zheng,\nZ. W. Guo, X. L. Zhao, B. X. Zhang, C. W. Wang, S. L. Xie,\nP. Wang, X. B. Li, W. X. Peng, R. Qiao, J. Wang, H. S. Zhao,\nZ. H. An, C. Chen, G. Chen, W. Chen, M. Gao, K. Gong, D. Y. Guo, J. J. He,\nB. Li, C. Li, C. Y. Li, J. H. Li, Q. X. 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,  D. L. Shi, J. Y. Shi, L. M. Song, G. X. Sun, X. L. Sun, Y. L. Tuo,\nJ. Z. Wang, X. Y. Wen, Y. B. Xu, Y. P. Xu, S. Yang, M. Yao, B. X. Zhang,\nC. Y. Zhang, D. L. Zhang, Fan Zhang, Fei Zhang, H. M. Zhang, K. Zhang,\nP. Zhang, S. N. Zhang, Z. Zhang, S. Y. Zhao, S. J. Zheng, X. Zhou (IHEP),\nreport on behalf of GECAM team:\n\nDuring the commissioning phase, GECAM-B triggered a long hard GRB,\nGRB 210522A, at 2021-05-22T22:11:44.450 UTC (denoted as T0), \nwhich was also observed by CALET/GBM, INTEGRAL/SPI-ACS and Konus-WIND.\n\nAccording to the GECAM-B light curves in about 8 keV-4 MeV, \nthis burst mainly consists of multiple pulses with a duration of about 50s.\n\nThe GECAM light curve could be found here:\nhttp://twiki.ihep.ac.cn/pub/GECAM/GRBList/gecamb_grd_75420704.45.png\n\nGECAM-B localized this burst to the following position (J2000):\nRa: 90.06 deg\nDec: 1.36 deg\nErr: 1.19 deg (1-sigma, statistical only)\nThe current systematic error of location is estimated to be several degrees\nwhich could be minimized by the ongoing calibration. \n\nIn addition, we derived a triangulation location for this burst using\nGECAM-B data together with public data of INTEGRAL-SPI/ACS and Konus-WIND,\nbased on a novel method (S. Xiao, et al., submitted). \nAlthough there are two intersection regions of triangulation annuli, only one\nregion is consistent with the above location given by GECAM-B alone, thus is\nthe final location region (3-sigma), which could be defined as (J2000):\n        Ra (deg)  Dec (deg)\nCenter  85.78, 2.09\nCorner\n        83.67, 0.30\n        79.45, 2.09\n        90.00, 2.69\n        87.89, 3.88\n\nThe location map could be found here:\nhttp://twiki.ihep.ac.cn/pub/GECAM/GRBList/location_gecamb_grd_75420704.png\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).\n\nWe are very grateful for the public data of INTEGRAL-SPI/ACS and Konus-WIND.",
  "circularId": 30070,
  "createdOn": 1621787605000,
  "email": "xiaoshuo@ihep.ac.cn",
  "subject": "GRB 210522A: GECAM detection",
  "submitter": "Shuo Xiao at IHEP  <xiaoshuo@ihep.ac.cn>",
  "eventId": "GRB 210522A"
}