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GCN Circular 915

Optical observations of GRB 001018 with JCAM
2001-01-18T20:00:39Z (23 years ago)
Josh Bloom at CIT <>
Optical observations of GRB 001018 with JCAM

J. S. Bloom, A. Diercks, S. R. Kulkarni, F. A. Harrison, (Caltech), B. B.
Behr (U. Texas), J. C. Clemens (UNC) report on behalf of the larger
GRB-NRAO-CARA GRB collaboration:

"On 18 December 2000 UT, J. Bloom and D. Reichart observed the field of
GRB 001018 (Hurley et al., GCN #853) near the transient radio position
reported by Taylor et al. (GCN #857) on the Palomar 200-inch telescope
during a commissioning run of the Jacobs Camera (JCAM), a dual-CCD imager
designed primarily for rapid follow-up of GRB afterglow.  The plate scale
of JCAM is 0.38 arcsec/pixel and the field-of-view is 3.2 x 3.2 arcmin^2.

We observed the GRB field simultaneously in R- and B-band for a total of
2700s. An astrometric plate solution was obtained using 10 (11) ties stars
common to both the USNO-A2.0 catalogue and the R- (B-) band summed image.  
The total absolute astrometric uncertainty in the R-band plate solution
was 0.32", 0.27" in RA and Dec.  Unfortunately, the seeing (2.8 arcsec
FWHM in R-band) was very poor at Palomar on 18 December and there was
significant extinction due to cirrus. At the position of Taylor's radio
transient there were no detected objects to R~22.7 mag (5-sigma); the
photometric zeropoint was estimated using the USNO stars in the field."

The R and B finding chart images of the may be obtained at:

For further information on JCAM, please see:

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