TITLE: GCN CIRCULAR NUMBER: 280 SUBJECT: GRB 990316, Optical observations DATE: 99/03/19 18:01:47 GMT FROM: Titus Galama at U.Amsterdam T.J. Galama (U. of Amsterdam), E. Pian, E. Palazzi, F. Frontera, N. Masetti (ITESRE, CNR, Bologna), K.C. Sahu (STScI), P.M. Vreeswijk, E. Rol (U. of Amsterdam), J. van Paradijs (U. of Amsterdam and U. of Alabama in Huntsville), C. Kouveliotou (USRA/MSFC), O. Hainaut, and V. Doublier (ESO/Chile) report: "We have observed the location of the LOTIS candidate optical transient reported by Park et al (GCN 277) with the European Southern Observatory (ESO) New Technology Telescope (NTT) on March 18.18 and March 19.17 in V and R for 900 sec each. We do not find objects variable by more than 0.25 magnitudes down to V = 24.1, R = 24.3 in a 2 x 2 arcmin region around the LOTIS position. The magnitudes are measured relative to a star at RA 09:50:13.26, DEC -04:57:45.6 (V = 19.25; R = 19.03; we estimate an absolute calibration uncertainty of 0.15 magnitude). " This message is citeable.