GCN Circular 796
Subject
GRB000911: Optical Transient
Date
2000-09-19T23:51:27Z (24 years ago)
From
Paul Price at RSAA, ANU at CIT <pap@srl.caltech.edu>
P.A. Price (RSAA,ANU/Caltech), T.J. Galama (Caltech), R.W. Goodrich (W.M.
Keck Observatory) and A. Diercks (Caltech) report on behalf of a larger
collaboration:
"We have observed the optical transient candidate of GRB000911 (Berger
et. al., GCN #795) with the Keck II telescope + ESI, starting at Sep 15.59 UT.
We took 5 x 120 second images in 0.6 arcsec seeing. We have compared
the combined image with the R_MACHO (~ Cousins R) image from the MSO 50-inch
telescope (Price et. al., GCN #793), using the USNO-A2.0 star U0975_00513791
(RA2000, Dec2000 = 02:18:33.18, +07:45:47.6) with assumed R = 18.6. Results
are:
Telescope Epoch Magnitude
MSO50+MACHO Sep 12.73 20.257 +/- 0.167
Keck+ESI Sep 15.59 21.911 +/- 0.053
(Errors are purely statistical.)
In the Keck+ESI image, the candidate is located at
(RA2000, Dec2000) = (02:18:33.21, +07:45:47.86) +/- (0.34", 0.31")
and has a PSF consistent with a point source. From these figures,
we calculate a decay constant of alpha = 1.4.
In the light of the fading nature of the candidate, it is likely
the optical transient associated with GRB000911."
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