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GCN Circular 398

Subject

Optical Observations of GRB990806

Date

1999-08-09T17:51:28Z (25 years ago)

From

Elena Pian at ITESRE-CNR,Bologna <pian@tesre.bo.cnr.it>

P.M. Vreeswijk (U. of Amsterdam), E. Palazzi, E. Pian, F. Frontera
(ITESRE, CNR, Bologna), M. Bessell (Mount Stromlo Obs.), J.  Hjorth, B.
Milvang-Jensen, H. Pedersen (CUO, Copenhagen), J. van Paradijs (U. of
Amsterdam and U. of Alabama in Huntsville), and C. Kouveliotou
(USRA/MSFC)  report on behalf of the Bologna/Rome, Amsterdam/Huntsville
and Copenhagen GRB optical follow-up teams:

"We have observed the error box of GRB990806 (Piro 1999, GCN 392Not found
 
 
)  at the
40inch telescope at the Siding Spring Observatory (3.8 hours after the
burst) and at the ESO Danish 1.54m telescope.  A log of the observations
is reported in the following Table: 


       Date       Telescope    ExpoTime  Band    Lim.mag. 
       (UT)                    (min)           (5 sigma, ap. rad.=FWHM)

 1999 August 6.76  40inch       40        R      22.0
      August 6.80  40inch       60        B      21.5 
      August 7.24  1.54m+DFOSC  50        R      22.8
      August 7.40  1.54m+DFOSC  10        B      22.4


Comparison between the 40inch images and Danish images does not reveal a
source varying by more than 0.3 magnitudes both in the R and B band.

The ESO Danish R-band image can be inspected at

http://tonno.tesre.bo.cnr.it/~pian/grb/grb990806.html

This message is citeable."