{
  "bibcode": "2022GCN.32159....1N",
  "body": "M. Niwano, S. Sato, M. Tateda, N. Higuchi, T. Hattori, R. Hosokawa, K. \nL. Murata, M. Sasada, N. Ito, Y. Takamatsu, Y. Imai, Y. Yatsu, and N. \nKawai (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 GCN Circular #32130, E. Bissaldi et al. GCN \nCircular #32131, P. A. Evans et al. GCN Circular #32132, J. Mangan et \nal. GCN Circular #32133, B. Sbarufatti et al. GCN Circular #32135, \nTohuvavohu et al. GCN Circular #32136, Y. Imai et al. GCN Circular \n#32138, K. Yamaoka et al. GCN Circular #32139, R. Gopalakrishnan et al. \nGCN Circular #32140, D. Xu et al. GCN Circular #32141, S. de Wet et al. \nGCN Circular #32143, P. D'Avanzo et al. GCN Circular #32145, T. Sun et \nal. GCN Circular #32146, A. Lysenko et al. GCN Circular #32152, W. Zheng \net al. GCN Circular #32158) with the optical three color (g', Rc, and \nIc) CCD cameras attached to the MITSuME 50 cm telescope Akeno.\n\nThe observation with a series of 60 sec exposures started at 2022-05-28 \n16:06:39 UT (1.3 days after the AGILE detection). We stacked the images \nwith good conditions. The point source was presumably detected at the \nSwift/XRT position (Sbarufatti et al. GCN Circular #32135) with S/N~3 \nonly in the Rc-band image. Here we report the Rc-band magnitude by the \nforced-photometry at the position and 5-sigma limits.\n\nT0+[days] | MID-UT | T-EXP[sec] | magnitudes of forced-photometry | \n5-sigma limits\n------------------------------------------------------------------------------------------------\n1.3 | 2022-05-28 17:39:36 | 4980 | Rc=20.5+/-0.3 | g'<18.6, Rc<19.3, Ic<18.5\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, Issue \n1, Pages 4-24; https://github.com/MNiwano/Eclaire).",
  "circularId": 32159,
  "createdOn": 1654250443000,
  "email": "niwano@hp.phys.titech.ac.jp",
  "subject": "GRB 220527A: MITSuME Akeno continued optical observation",
  "submitter": "Masafumi Niwano at Tokyo Institute of Tech  <niwano@hp.phys.titech.ac.jp>",
  "eventId": "GRB 220527A"
}