{
  "bibcode": "2022GCN.32138....1I",
  "body": "Y. Imai, S. Sato, R. Hosokawa, K. L. Murata, M. Sasada, M. Niwano, N.\nIto, Y. Takamatsu, M. Tateda, T. Hattori, Y. Yatsu, and N. Kawai\n(Tokyo Tech) report on behalf of the MITSuME collaboration:\n\nWe observed the field of GRB 220527A (A. Ursi et al. GCN Circular\n#32129, The Fermi GBM team et al. GCN Circular #32130, Bissaldi  et\nal. GCN Circular #32131, Evans et al. GCN Circular #32132, Mangan et\nal. GCN Circular #32133, Sbarufatti et al. GCN Circular #32135,\nTohuvavohu et al. GCN Circular #32136,) with the optical three color\n(g', Rc, and Ic) CCD cameras attached to the MITSuME 50 cm telescope\nAkeno.\n\nThe observation with a series of 60 sec exposures started at\n2022-05-27 16:05:50 UT (6.8 hours after the AGILE detection). We\nstacked the images with good conditions. Here we report magnitudes by\nthe forced-photometry at the Swift/XRT position (Sbarufatti et al. GCN\nCircular #32135).\n\nT0+[hour] |MID-UT | T-EXP[sec] | magnitudes of forced-photometry\n------------------------------------------------------------------------------------------------\n7.5 | 2022-05-27 16:46:53| 3780 | g'=18.9 +/- 0.2, Rc=18.5 +/- 0.1,\nIc=18.3 +/- 0.1\n8.7 | 2022-05-27 17:58:38| 3420 | g'=18.9 +/- 0.2, Rc=18.6 +/- 0.1,\nIc=18.7 +/- 0.2\n------------------------------------------------------------------------------------------------\nT0+ : Elapsed time after the burst\nT-EXP: Total Exposure time\n\nWe used PS1 catalog for flux calibration. The magnitudes are expressed\nin the AB system. The images were processed in real-time through the\nMITSuME GPU reduction pipeline (Niwano et al. 2021, PASJ, Vol.73,\nIssue 1, Pages 4-24; https://github.com/MNiwano/Eclaire).",
  "circularId": 32138,
  "createdOn": 1653705476000,
  "email": "imai@hp.phys.titech.ac.jp",
  "subject": "GRB 220527A: MITSuME Akeno optical observation",
  "submitter": "Yuri Imai at Tokyo Inst of Tech  <imai@hp.phys.titech.ac.jp>",
  "eventId": "GRB 220527A"
}