[AAVSO-HEN] GRB 080218b, SMARTS optical/IR limits

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
For an archive and more information on circulars visit:
http://lheawww.gsfc.nasa.gov/docs/gamcosray/legr/bacodine/gcn3_archive.html

TITLE:   GCN CIRCULAR
NUMBER:  7318
SUBJECT: GRB 080218b, SMARTS optical/IR limits
DATE:    08/02/19 03:55:24 GMT
FROM:    Bethany Cobb at Yale U  <cobb at astro.yale.edu>

B. E. Cobb, part of the larger SMARTS consortium, reports:

Using the ANDICAM instrument on the 1.3m telescope at CTIO, we
obtained optical/IR imaging of the error region of GRB 080218b
(Schady et al. GCN 7314) with a mid-exposure time of ~3.1 hours
post-burst (2008-02-19 03:03 UT).  Total summed exposure times amounted
to 18 minutes in I and 15 minutes in J.

No source is detected at the position of the X-ray
afterglow (Schady et al. GCN 7314) to approximate
limiting magnitudes of I > 21.1 and J > 18.7. Magnitudes
are calibrated using USNO-B1.0 values for I, and 2MASS
values for J.