TITLE: GCN GRB OBSERVATION REPORT NUMBER: 461 SUBJECT: GRB991208, optical observations DATE: 99/12/15 19:42:33 GMT FROM: Vladimir Sokolov at SAO RAS GRB 991208 SAO RAS follow-up observations S. Dodonov, V. Afanasiev, V. Sokolov, V. Komarova, T. Fatkhullin, A. Moiseev report: "One 2700-sec spectrum and one 4500-sec spectrum of the optical transient of GRB 991208 detected by A.Castro-Tirado et al., (GCN #452) were obtained on the nights of the 13th and 14th Dec 1999 UT respectfully with the SAO RAS 6-meter telescope at the Northern Caucasus. Observational conditions on the night of the 13th of December were poor. The seeing was 3 arcsec and the transparency was not good. On the 14th of December the observational conditions were good: the seeing ~1.5 arcsec (at a zenithal distance of 60 degrees), a good transparency. So, the first spectrum is with a poor S/N ratio, the second one is much better. The observations were carried out with the integral field spectrograph (Multi Pupil Fiber Spectrograph, MPFS http://www.sao.ru:8100/~gafan/devices/mpfs/mpfs_main.htm) with 300 lines/mm grating blazed at 6000 A giving a spectral resolution of about FWHM=14A/px and effective wavelength coverage of 4100 - 9200 A. A spectrophotometric standards HZ44 and BD+75d325 (Oke et al. 1995) were used for the flux calibration. The spectra show a blue continuum and in the second one with better S/N there are possible two emission lines. The data are being processed. On the second night (on Dec 14.14 UT) simultaneously with spectroscopic observations at the 6-meter telescope we imaged the field of GRB991208 in the R_c band (Cousins) with the SAO RAS 1-m telescope (Zeiss-1000). Two 10-minute exposures were obtained at an airmass of ~1.6 in good photometric conditions. The seeing was of ~2 arcseconds. The brightness estimate was made for optical counterpart of GRB 991208: R_c = 21.6 +/- 0.3. For photometric calibration Landolt standards were used. This message may be cited." -Vladimir Sokolov, on behalf of the RAS Special Astrophysical Observatory GRB followup team.