{
  "bibcode": "1998GCN...142....1P",
  "body": "H.Pedersen, Copenhagen University Observatory,\nH.Korhonen, Nordic Optical Telescope, La Palma, \nA.O.Jaunsen, Institute for Theoretical Astrophysics, Oslo, \nI.Ilyin & R.Duemmler, University of Oulu, and\nF.Frontera, Inst.TeSTRE, Bologna (on behalf of the BeppoSAX team), report:\n\nOn July 4, 5, 6, and 7 we obtained R band images (600 sec each, seeing \n0.75\"-1.0\" FWHM) of the GRB980703-field using the 2.56-m Nordic Optical \nTelescope. The field-of-view was 3' x 3' and all images were acquired under \ngood photometric conditions.\n\nImages taken during the first three nights were centered on the position \ninitially reported from RXTE by Levine et al. (IAUC 6966) and missed the \nradio- and optical transient (Frail et al., GCN #128) by ~8 arcsec.\n\nIntercomparing these images we found one variable star. Its position is \nR.A. 23:59:03.7, Dec. +08:33:51.3 (J2000). An approximate R-band zero-point \nis determined from the USNO catalogue entry U0975_21757527 (a star 15\" SW \nof the OT), which has R=16.5. This gives the following photometry for the \nnew variable:\n\n   UT                Var  \n\n   1998 July 04.101  R= 21.0 +/- 0.2\n             04.149  R= 21.1 +/- 0.2\n             04.194  R= 21.6 +/- 0.2\n             05.086  R= 21.5 +/- 0.2\n             05.146  R= 21.2 +/- 0.2\n             05.195  R= 21.1 +/- 0.2\n             06.188  R= 21.1 +/- 0.2\n\nAn image centered on the RT/OT was taken on July 7. For the OT we find the \nfollowing R-band magnitude (using the already mentioned standard star):\n\n   1998 July 07.163  R= 22.45 +/- 0.2\n\nThe errors reflect a conservative estimate of the uncertainty in the\ndetermination of the zero-point. \n\nOur result is consistent with a power-law decline as reported by Bloom et al. \n(GCN #136) when comparing to other reported R-band values.\n\nFurther information can be found on http://vega.uio.no/~ajaunsen/grb980703\n\nThis message can be cited.",
  "circularId": 142,
  "createdOn": 899990061000,
  "email": "holger@astro.ku.dk",
  "subject": "GRB980703 optical observations",
  "submitter": "Holger Pedersen at Copenhagen U Obs  <holger@astro.ku.dk>",
  "eventId": "GRB 980703"
}