{
  "bibcode": "2007GCN..6575....1K",
  "body": "I. Khamitov (TUG), I. Bikmaev, N. Sakhibullin (KSU/AST),\nZ. Tunca (TUG), U. Kiziloglu (METU), E. Gogus (Sabanci Uni.),\nR. Burenin, M. Pavlinsky, R. Sunyaev (IKI)\n\nreports:\n\nWe observed the field of GRB 070621 (Sbarufatti et al., GCN 6530) with\nRussian-Turkish 1.5-m telescope (RTT150, Bakyrlytepe,TUBITAK National\nObservatory, Turkey). We made 16x60s exposures in R band, starting at June\n21, 23:25:40UT, i.e. approximately 500 s after the burst.\n\nWe detected no sources inside the XRT error circle in any of 60~s image,\nas well as in combined 16x60~s image with 3-sigma limiting magnitudes\nm_R=~20.8 and m_R=~22.3 respectively.\n\nThe source reported by Melesani et al (GCN 6565) is clearly detected on \nthe level m_R=22.15+/-0.2 using the same reference star USNO-B1 \n0651-0871887, i.e. is not variable within the errors. The astrometric \nposition of this source is RA=21:35:10.12, DEC=-24:49:07.2 with 0.1 arcsec \naccuracy.\n\nThe sourse to the east from XRT position, which was found in Gemini\nSouth data (s4, Bloom et. al., GCN 6568), and in image from Keck II LGS\nAO (i2, Bloom et. al., GCN 6572) is also detected marginally near the\nlimit of our combined image.\n\nThis message may be cited.",
  "circularId": 6575,
  "createdOn": 1182608532000,
  "email": "irekk@tug.tug.tubitak.gov.tr",
  "subject": "GRB070621: RTT150 optical observations",
  "submitter": "Irek Khamitov at TUG  <irekk@tug.tug.tubitak.gov.tr>",
  "eventId": "GRB 070621"
}