//////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 276 SUBJECT: GRB990316 - Optical null results DATE: 99/03/17 14:59:23 GMT FROM: Elia Leibowitz at Wise Obs, Tel Aviv U P. Ibbetson, E.O. Ofek and E.M. Leibowitz report: On March 16 1999, some 7.5 hours after the outburst of GRB990316 (Trigger Num. 7475), using the 1 m telescope of the Wise Observatory, we have taken 5 CCD frames of 900 seconds exposure and FOV of 11x11 arcmin^{2} each, through an R filter. Together they cover a square box of nearly 0.3x0.3 deg^{2} around RA=10:06:16 Dec=-05:13:31 (J2000), at the mean UT 17:34. We have not identified any new object relative to the corresponding DSS images, up to a limiting magnitude of 19.5. Within a box of 11x11 arcmin^{2} around the central point the limiting magnitude is 19.9. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 277 SUBJECT: GRB990316: simultaneous optical observation DATE: 99/03/18 03:27:59 GMT FROM: Hye-Sook Park at LLNL H.S. Park, L. Ott, R. Porrata (LLNL), G. Williams, D. Hartmann (Clemson Univ.) report on behalf of the LOTIS collaboration: LOTIS obtained realtime images of GRB990316 (BATSE Trigger 7475). LOTIS started recording the first image 13.6 sec after the burst (on the rising edge of the GRB light curve). The first image was taken with a 30 s integration time, thus this image completely overlapped the remainder of the GRB gamma-ray emission which lasted a total of ~40 sec. The first image from one of our 4 cameras (each with 8.8 x 8.8 deg field of view) covers > 98% of the BATSE 3 sigma (0.3 deg statistical + 1.6 deg systematic) error circle. The GRB location is further constrained by an annulus derived from IPN data (GCN/IPN notice) that passes through the BATSE error circle in the image. We searched for optical transients in this image by 1) comparing background images taken at later times and 2)comparing the stellar objects in the image with objects in the Guide Star Catalog and Digital Sky Survey images. We found one transient object at RA=147.54, DEC=-4.95 (J2000) near the edge of the IPN annulus with V~12.5 brightness. This object was seen only in the first image. No object is seen in the DSS image at this location. The second image was started after the gamma ray emission was over (at 55 sec after the start of the burst). We cannot rule out the possibility that this OT is a local effect rather than associated with the gamma ray burst. However, we encourage follow up observations at this location for possible afterglow observations. Further analysis is in progress and associated data will be placed on our web page. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 278 SUBJECT: GRB 990316 optical observations DATE: 99/03/18 13:16:57 GMT FROM: James Rhoads at KPNO Howard E. Bond (Space Telescope Science Institute), Kevin M. McLin (CASA, University of Colorado), and James Rhoads (Kitt Peak National Observatory) report on behalf of the KPNO GRB followup team: We have observed the location of the LOTIS candidate optical transient reported by Park et al (GCN 277). Bond has obtained a 300 second V band image using the KPNO 4 meter Mayall telescope; the observation is centered at 1999 March 18, 06:45 UT. McLin observed the same field for a total of 1800 seconds in R band using the KPNO 0.9 meter telescope; the observations were centered at 06:30 UT. Conditions were clear with 1.6 to 1.7 arcsecond seeing. Comparing our images to the digitized POSS-II red plates, we find no compelling evidence for any new source above the POSS plate limit. This implies an approximate limit of R>21 for any fading source consistent with the location of the LOTIS candidate. (We have assumed that the positional uncertainty is less than 1 arcminute for the LOTIS source, based on the 15 arcsecond LOTIS pixel size. Our actual fields of view were 36' for the 4m and 23' for the 0.9m data, so could be used to search for transients over a larger area.) Our R and V band images are both deeper than the POSS plates, and further CCD photometry is encouraged to see whether any fainter sources are varying. The R band image and a subsection of the V band image are available on the Web from http://www.noao.edu/noao/grb/990316.html . Please note that these images are not fully reduced; they will be replaced with fully reduced images when available. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 279 SUBJECT: GRB990316, Optical observations DATE: 99/03/19 12:11:31 GMT FROM: Ion-Alexis Yadigaroglu at Columbia U I.-A. Yadigaroglu, C. Liu & J. P. Halpern (Columbia U.), H. E. Bond (STScI) report on behalf of the MDM Observatory GRB follow-up team: "We imaged in the V band the location of the LOTIS optical candidate (GCN 277) for GRB 990316 on Mar 19.22 using the MDM Observatory 2.4m telescope. A total of 40 minutes exposure was obtained in seeing of 1.0 arcsec. The image was compared to an image of the same region obtained the previous night at the KPNO 4m telescope (GCN 278). No fading objects are found in a conservative 2 arcmin radius around the LOTIS position. A calibration using a Landolt standard gives plate limits of 23.9 and 23.0 for the Mar 19.22 and 18.28 images respectively. For reference, the magnitudes of two nearby stars are V = 20.25 at (J2000) RA 9:50:14.6, Dec -4:56:32.3, and V = 20.14 at RA 9:50:14.9, Dec -4:56:56.3. An asteroid with V = 22.6 is detected on Mar 18.28 an arcminute away from the LOTIS position." This message may be cited. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT 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. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 281 SUBJECT: GRB 990316, Radio observations DATE: 99/03/21 22:34:17 GMT FROM: Titus Galama at U.Amsterdam T.J. Galama, P.M. Vreeswijk, E. Rol (U. of Amsterdam), J. van Paradijs (U. of Amsterdam and U. of Alabama in Huntsville), C. Kouveliotou (USRA/MSFC), R.G. Strom (NFRA and U. of Amsterdam) and A.G. de Bruyn (NFRA and U. of Groningen) report: "We have observed the location of the LOTIS candidate optical transient reported by Park et al (GCN 277) with the Westerbork Synthesis Radio Telescope (WSRT) at 4.88 GHz on March 20.90 (for 11 hours). We do not find any radio source brighter than 130 microJy (3 sigma) in a 2 x 2 arcmin region around the LOTIS position." This message is citeable. //////////////////////////////////////////////////////////////////////// TITLE: GCN GRB OBSERVATION REPORT NUMBER: 282 SUBJECT: GRB 990316 Optical Observations DATE: 99/03/22 23:26:48 GMT FROM: Andreas O. Jaunsen at Inst. for Theor. Astrophysics,Noa.o.jaunsen@astro.uio.no A. O. Jaunsen (University of Oslo), M. I. Andersen (Nordic Optical Telescope, La Palma), J. Hjorth, and H. Pedersen (University of Copenhagen) report: We obtained R band images of the area around the possible LOTIS optical counterpart to GRB 990316 (GCN #277) with the Nordic Optical Telescope on March 18.865 (1800 sec, FWHM = 1.40") and March 19.118 (1200 sec, FWHM = 1.45"). We find no evidence for variable objects in the 6' x 6' field centred on the LOTIS position. A plot of the difference in inferred magnitude versus magnitude for objects detected in the field is posted on the web page given below. Comparison between a combined image of our NOT data and the KPNO R-band image (Bond et al., GCN #278) also give no significantly variable object. All images obtained of the LOTIS position may be combined to reach fainter detection levels. For this purpose we make our fully reduced and WCS (USNO A2.0) calibrated NOT images available at http://www.astro.uio.no/~ajaunsen/grb990316/ .