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GCN Circular 1758

GRB 021211: CTIO observations
2002-12-15T13:26:17Z (21 years ago)
Andrew Levan at U.of Leicester <>
Andrew Levan (U. Leicester/STScI), Andrew Fruchter (STScI), Doug Welch
(McMaster), Chris Palma (Penn State), Bryan Henderson (U. Washington),
Michael Siegel and Ingunn Burud (STScI) report for a larger collaboration:

The optical afterglow of GRB 021211 was imaged with the CTIO 4m
telescope and Mosaic imager on the 12th Dec beginning 06:15UT and 13th
Dec at 06:11UT. On 12th Dec, 1440s were obtained in both R and I. On
13th Dec 2880s were obtained in R only. Each observation consisted of
several shorter, dithered observations.

The afterglow is clearly visible in both epochs. Using a
1" aperture we measure magnitudes in the first epoch of R=22.8, I=22.5
and in the second epoch of R=23.1, where photometry has been calibrated
using the calibration of Henden (GCN 1753). The host galaxy is
a clearly visible extension to the north-east of the OT.

Subtraction of a point source from the position of the optical transient
on its host indicates that the brightest point source present was
fainter than R=23.2 at the time of the first observations (t=19 hours),
and R=23.6 at t=43 hours. Implying that the host galaxy is brighter than

An image of the field, showing the OT and host galaxy on the night of
Dec 12th can be found at
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