{
  "bibcode": "2007GCN..6762....1R",
  "body": "V. Rumyantsev (CrAO) , V.Biryukov (SAI, MSU and CrAO), A. Pozanenko (IKI)\nreport on behalf of larger GRB follow-up collaboration:\n\nWe observed the error box of short GRB070810b  (Marshall et al., GCN 6743)\nwith Shajn 2.6m telescope of CrAO on Aug. 10.  Series of images were\nobtained between (UT) 2007-08-10 22:05:23 and 2007-08-10 23:25:50 in R\nfilter. The combined image of a total exposure of 4260 s (71x60 s) covers\nentire of the error box of GRB 070810b and can be found at\nhttp://grb.rssi.ru/GRB070810b/GRB070810b_ZTSh.gif. The limiting magnitude (3\nsigma) calibrated against USNO-A2.0 of the combined image is 24.8 mag.\n\nWe investigate  the S1, S2 XRT positions of GRB70810b (GCN 6754 , Starling\net al.) and S3 position  (Thoene et al., GCN 6756).\n\nThere is marginally detected object in a place of the source S1  (see\nhttp://grb.rssi.ru/GRB070810b/GRB070810b_s1_ZTSh.gif).\n\nBoth optical sources around S3 (RA = 00:35:46.892 Dec = +08:51:05.96) are\npresented in our and Keck's images, see\nhttp://grb.rssi.ru/GRB070810b/GRB070810b_s3_ZTSh.gif.\n\nComparison of objects around source S2  ( RA =  00h 35m 50.0s Dec = +08d 48'\n45.0'' ) in our image ( see\nhttp://grb.rssi.ru/GRB070810b/GRB070810b_s2_ZTSh.gif) with the image\nobtained on Aug. 11 (Thoene et al., GCN 6756) reveals a source between   two\nnearby galaxies. We consider this source as a candidate of the optical\ncounterpart of  GRB070810b and a redshift  z~0.49 obtained for the galaxies\n(Thoene et al., CN 6756) is quite natural for short GRB detected by Swift.\nHowever more detailed comparison of the images (Keck I and ZTSh) and\nadditional observations are necessary to secure the nature of the candidate.\n\nThe massage can be cited.",
  "circularId": 6762,
  "createdOn": 1187715901000,
  "email": "apozanen@iki.rssi.ru",
  "subject": "GRB070810b: optical candidate",
  "submitter": "Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>",
  "eventId": "GRB 070810B"
}