{
  "bibcode": "2021GCN.29281....1B",
  "body": "S. Belkin (IKI), A. Pozanenko (IKI), P. Minaev (IKI), M. Krugov (FAI)\nreport on behalf of GRB IKI FuN collaboration:\n\nWe continued observations of the field of XRT #2 sources (D'Elia et al.,\nGCN 29202) (hereafter X2) found in IPN localization area (Svinkin et\nal., GCN 29182) of GRB 201227A (Ursi et al., GCN 29179; Xiao et al., GCN\n29187; Svinkin et al., GCN 29196; Lesage et al., GCN 29206; Marisaldi et \nal., GCN 29276) with Chilescope RC-1000 on 2021-01-01 and 2021-01-08 in \nr'-filter.\n\nThe X2_O2 object found in previous observation on 2020-12-29 at r'(AB)=\n20.5 (Belkin et al., GCN 29208; see also Izzo et al., GCN 29207) is not\ndetected on 2021-01-01 with an upper limit of r'(AB) > 20.6 and barely\ndetected on 2021-01-08 at r'(AB)=22.6. Now we confirm the variability of\nthe object of X2_O2 and suggest the optical object X2_02 could be a\ncounterpart of GRB 201227A. In the last image on 2021-01-08, the object \nX2_O2 could be the host galaxy. A finding chart of the X2_O2 can be found in\n\nhttp://grb.rssi.ru/GRB201227A/GRB201227A_r_FC_201229_2100108.png\n\nPreliminary photometry of the X2_O2 is following\n\nDate UT start       t-T0 Filter Exp.  OT(AB) Err. UL(AB) FWHM\n                     (mid, days) (s)\n\n2021-01-01 05:57:21 4.63072 r' 5*600  n/d    n/d  20.6   1.5\"\n2021-01-08 04:15:45 11.5636 r' 3*1200 22.6   0.4  22.5   1.4\"\n\nThe photometry is based on nearby stars from the APASS_DR8\n\nRA DEC r\n11:19:31.40904 -73:35:47.6880 14.090\n11:19:44.89128 -73:34:49.6092 15.180\n11:19:36.65304 -73:36:30.2112 15.307\n\nIn addition we investigated a position of the GRB 201227A on the EHD \ndiagram (see Minaev et al., MNRAS, 492,  1919, 2020). The position of \nGRB 201227A based on Konus-Wind data (Svinkin et al., GCN Circ. 29196) \ncan be found in\n\nhttp://grb.rssi.ru/GRB201227A/GRB201227A_EH_T90i.png\n\nWe can exclude the GRB 201227A as a giant flare event of SGR since there \nis no nearby galaxies in the IPN error box. We can identify the GRB \n201227A as short GRB at a redshift of z > 0.05.",
  "circularId": 29281,
  "createdOn": 1610122833000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB 201227A: continued Chilescope confirmation of variability of possible optical counterpart, redshift estimating",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 201227A"
}