Gamma-ray Burst 990217

A Gamma-Ray Burst was detected by the BeppoSAX GRB monitor on 1999 February 17, 5:23:27 UT and localized to 3' accuracy.

(All information courtesy of the instrument teams.)

Previous IAU Circulars

• IAUC 7110 BeppoSAX WFC detection and localization
• IAUC 7111 no X-ray afterglow in BeppoSAX NFI observation

• BeppoSAX MAIL n. 99/4
  On Feb.17, 5:23:27 UT a GRB (GB990217) was detected simultaneously by the GRBM and WFC of BeppoSAX.
  Preliminary coordinates from WFC are:

  R.A.(2000)= 45.784
  DEC(2000)= -53.136
  

  with an error radius of about 4'
  A follow-on with NFI is being planned.
• BeppoSAX MAIL n. 99/5
  GB990217 refined WFC positions are

  R.A.(2000)= 45.7177
  DEC(2000)= -53.0935
  

  with an error radius of about 3'
  A follow-on with NFI will start today around 12.00 UT.
• GCN notice #258
  Luigi Piro, BeppoSAX Mission Scientist, reports:
  GB990217 refined WFC positions are:

  R.A.(2000)= 45.7177
  DEC(2000)= -53.0935
  

  with an error radius of about 3'
  A follow-on with NFI will start today around 12.00 UT
• GCN notice #259
  Bradley E. Schaefer (Yale) reports:
  I have examined the BeppoSAX error circle for GRB990217 (Tarei et al. IAUCirc 7110) with the Yale 1-m telescope on Cerro Tololo. At this early time, the only comparison available is the Digital Sky Survey, and no optical transient is apparent. The images were taken in R and I starting at 18 February 2:17 UT with 900s exposures, and these reach considerably deeper than the Digital Sky Survey.
• GCN notice #262
  E. Palazzi, N. Masetti, E. Pian, F. Frontera (ITESRE-CNR, Bologna), P.M. Vreeswijk, E. Rol, T.J. Galama, G. Dubus (U. of Amsterdam), J. van Paradijs (U. of Amsterdam and U. of Alabama in Huntsville), C. Kouveliotou (NASA-MSFC/USRA), O. Hainaut (ESO), C. Tinney (AAT), T. Axelrod, B. Schmidt, and H. Jones (MSSSO), on behalf of a large collaboration, report:
  Images of the GRB 990217 error box (Tarei et al. 1999, IAU Circ. 7110) were acquired on 1999 Feb 17.50 UT at Siding Spring with the 40-inch telescope (R band), on Feb 17.48 at Mount Stromlo with the 74-inch telescope (R), on Feb 17.54 with the 50-inch telescope (B and R), on Feb 18.03-18.07 and Feb 19.04-19.12 at ESO-La Silla with NTT+EMMI (B and R). Limiting magnitudes were R~22.5 for the 40-inch, B~20 and R~21 for the 50-inch, R~22 for the 74-inch, B~24.5 and R~24.5 for NTT on Feb 18, and B~24 and R~23.5 for NTT on Feb 19.
  Comparison between the NTT images of Feb 18 and 19 shows no object varying by more than 0.3 magnitudes down to R~23.5 and B~24 within the error box in either band. Similarly, the comparison between the 40-inch and the Feb 18 NTT R band images shows no object varying by more than 0.3 magnitudes down to R~22.5 within the error box.
• GCN notice #263
  L. Amati, F. Frontera and N. Masetti (ITESRE/CNR, Bologna), E. Montanari (University of Ferrara), E. Costa, M. Feroci and L. Piro (IAS/CNR) report on behalf of the BeppoSAX/GRBM Team:
  The BeppoSAX Gamma Ray Burst Monitor detected GRB990217 (IAUC #7110) as a weak, single pulse gamma-ray burst lasting about 25 s. The total fluence in the 40-700 keV energy range is 4307 +/- 195 counts, corresponding to (1.3 +/- 0.2) x 10E-6 erg cmE-2. The 1 s peak flux in the same band is 146 +/- 43 counts/s, corresponding to (1.1 +/- 0.3) x 10E-7 erg cmE-2 sE-1. For a comparison, the peak flux in the 2-26 keV range as measured by the BeppoSAX/WFC N. 2 (IAUC #7110) is about 0.5 Crab, that corresponds to 1.64 x 10E-8 erg cmE-2 sE-1. The average photon index inferred from the GRBM data with the assumption of a single power-law is 1.52 +/- 0.55. The low statistical quality of the data does not allow to better constrain the spectral model.
• GCN notice #266
  R. Wark (CSIRO), M. Wieringa (CSIRO, D. A. Frail (NRAO) and S. R. Kulkarni (Caltech) report on behalf of a larger collaboration:
  Beginning at 7:39 UT on 1999 February 18 we observed a region covering the WFC error circle of GRB 990217 (GCN #258, IAU Circ 7710) with the Australia Telescope Compact Array (ATCA) at 4.8 GHz and 8.6 GHz. The total observing time was 3.6 hours.
  Within a 3 arcmin radius around the GRB position no radio sources were detected down to 0.28 mJy (5 sigma) at either frequency. Deeper ATCA observations are planned for this week.
• GCN notice #267
  K. Pedersen (Danish Space Research Institute, Copenhagen), J. Hjorth, H. Pedersen (Copenhagen University Observatory), and A.O. Jaunsen (Institute for Theoretical Astrophysics, Oslo) report:
  We have observed the field of GRB 990217 (Tarei et al., IAUC 7110), using the DFOSC instrument on the 1.54-m Danish telescope at La Silla. All exposures were done in the R band. The field covered was 13.6 x 13.6 arcminutes, hence significantly larger than the BeppoSAX error circle.

  UTC (mid exposure)    Exp.    Seeing (fwhm)   Limit
  
  1999 Feb 19.049      1200 s        1.4"      < 23.1      
  1999 Feb 20.034      1000 s        1.4"      < 23.0 
  1999 Feb 24.037       600 s        1.2"      < 22.8 
  

  Intercomparison of the exposure shows no variable object.