GCN Circular 130
GRB 980703. NEW OPTICAL OBSERVATIONS ------------------------------------ M.R. Zapatero Osorio (Instituto de Astrofisica de Canarias, IAC, E-38200 La Laguna, Tenerife, Spain) A. Castro-Tirado (Laboratorio de Astrofisica Espacial y Fisica Fundamental, LAEFF-INTA, Madrid) J. Gorosabel (LAEFF) A. Oscoz, S. Kemp (IAC) F. Frontera, L. Nicastro (on behalf of the BeppoSAX team) Report: Images in the R-band have been obtained at the 0.8-m IAC80 telescope (Teide Observatory) on July 4 and 6 including the BeppoSAX error box for the X-ray source 1SAX J235907+0835 presumably related to GRB980703 which was detected by both BATSE and RXTE. These data reveal an object located at RA = 23h 59m 6.7s DEC = 8d 35' 7'' (+/- 2'', Eq. J2000) which has faded by about 1.5 mag at this wavelength. A preliminary photometric analysis allows us to determine R = 20.6 +/- 0.1 (July 4.123 UT) and 22.1 +/- 0.2 (July 6.137 UT). No other objects varying by more than 0.2 mag are seen down to a limiting magnitude of R = 22.5. A finder chart is available via anonymous ftp to ftp.ll.iac.es (cd publong/grb980703/).