Gamma-ray Burst 991217

On December 17, 1999, 04:12:20 UT a faint, but X-ray rich event was detected by BeppoSAX.

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• none

• BeppoSAX GRB Alert
  On Dec.17, 04:12:20 UT a faint X-ray rich event with a marginal detection in GRBM (GRB991217) was detected by BeppoSAX WFC2.
  Preliminary coordinates from WFC are:

    R.A.(2000)= 345.867
    DEC (2000)= 0.228
  

  with an error radius of about 6'. The position error is the standard statistics+systematics, but the satellite was in testing mode, so the estimate is very preliminary. For the same technical reason an NFI observation is not being planned.
• BeppoSAX MAIL n. 99/35
  Refined coordinates from WFC are:

    R.A.(2000)= 345.812
    DEC (2000)= 0.249
  

  with an error radius of about 4.5'. At this stage an additional systematic error due to the testing mode cannot be excluded.
• GCN notice #474
  J.M. Muller and E. Kuulkers, SRON, Utrecht, G. Tarei and L. Di Ciolo, BeppoSAX Scientific Operation Centre, Telespazio, Roma, L. Amati, TESRE/CNR, Bologna, C. Guidorzi, Universita' di Ferrara, G. Gandolfi, IAS/CNR, Roma, report:
  The BeppoSAX Wide Field Camera (WFC unit 2) observed a new fast x-ray transient (SAX J2303.2+0015) on December 17.17496 UT. The duration was about 35 s and the peak flux was about 0.6 Crab (2-26 keV) in a 1 second time bin. No significant signal was detected in the GRBM (40-700 keV). The high galactic latitude of the x-ray transient and the high hardness ratio found in a quick-look analysis, may suggest a faint and x-ray rich GRB. The position of the source is R.A. = 23h03m15s Decl. = +0d14'.93 (equinox 2000.0) with an estimated error radius of 4.5'. No catalogued x-ray objects were found within a radius of 10 arcmin. Note that at this point we cannot exclude an additional systematic position error due to ongoing tests with the satellite startrackers.
• GCN notice #482
  A. Henden (USRA/USNO) reports that there is an asteroid currently moving through the SAX error box, about two arcmin south of the center, in an easterly direction. Short exposures might confuse the naive observer into thinking a new object is present.
  
• GCN notice #490
  A. Henden (USRA/USNO), F. Vrba, H. Harris, C. Luginbuhl, B. Canzian, J. Munn, S. Levine, H. Guetter (USNO), D. H. Hartmann (Clemson Univ.), M.C. Jennings (IGPP, UCR visitor), J. A. Smith (U. Mich.) report:
  We have imaged the BeppoSAX WFC error box for SAX J2303.2+0015 (also referred to as GRB 991217) as reported by Muller, et. al. (GCN 474). Both the 1.0-m and 1.3-m (wide field) telescopes were used, with V and R exposures.
  Conditions were marginal; light to moderate cirrus illuminated by the moon prevented individual images from going deeper than the DSS/POSS-II image. However, at that limit, we see no new object within the SAX 4.5 arcmin error box.
• GCN notice #493
  S. Kassin (Ohio State U.), S. Novati (CdF), J. Halpern (Columbia U.) report:
  We have imaged the BeppoSAX WFC error box for SAX J2303.2+0015 reported by Muller, et. al. (GCN 474) on the 1.3-m at MDM with a nonstandard broad R filter. We took four fifteen mintue exposures in bright moonlight. Our field of view was 1024 x 1024 arc seconds.
  Comparing our images to the DSS/POSS-II plates, we have not found any new object. However, like Henden et. al. (GCN 490), our observations did not go deeper than the DSS/POSS-II image. They reached the same magnitude.
• GCN notice #501
  C. Bartolini, A. Guarnieri, A. Piccioni (Dip. Astronomia, U. of Bologna), A. De Blasi (Oss. Astron. Bologna) and N. Masetti (ITeSRE-CNR, Bologna) report:
  Five R-band images of the BeppoSAX WFC error box of GRB991217/SAX J2303.2+0015 (Muller et al. 1999, GCN #474) were obtained with the Bologna Astronomical Observatory 1.5-meter telescope equipped with BFOSC between Dec. 17.727 and 17.814, for a total exposure time of 55 min.
  These observations, which started about 13 hours after the high-energy event, were summed together and compared with the DSS-2. Altought somewhat deeper than the DSS-2, the summed R frame does not show any remarkable new object.
• GCN notice #502
  Vijay Mohan, Ram Sagar, Anil K. Pandey, S.B. Pandey (from UPSO, Nainital), Javier Gorosabel and Alberto J. Castro-Tirado (LAEFF-INTA, Madrid and IAA-CSIC, Granada) -on behalf of a larger European collaboration- report:
  We have obtained several images of the BeppoSAX WFC error box for SAX J2303.2+0015 (also referred to as GRB 991217) as reported by Muller, et. al. (GCN 474) with the 2k x 2k CCD camera mounted at the f/13 Cass focus of the UPSO 104-cm Sampurnanand telescope on 1999 Dec 17.63, Dec 18.65 and Dec 19.55 in R photometric passband during photometric sky conditions. The corresponding exposure times are 120, 60 and 60 minutes respectively. Our field of view was 780 x 780 arc seconds. After a visual comparison of our images with digital sky survey, though we detect several faint objects yet no object varying like an OT of a gamma-ray burst was detected. Our images go as faint as R = 22.0 magnitude. This indicates that the OT of this GRB if any is fainter than 22nd magnitude in R.