[AAVSO-HEN] GRB 090118: GROND Upper 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:  8826
SUBJECT: GRB 090118: GROND Upper Limits
DATE:    09/01/19 02:23:14 GMT
FROM:    Andrea Rossi at TLS Tautenburg  <rossi at tls-tautenburg.de>

F. Olivares (MPE Garching), A. Rossi (Tautenburg Obs.), A. Kupcu Yoldas (ESO), J. Greiner, and A. Yoldas (both MPE Garching) report on behalf
of the GROND team:

We observed the field of the possible GRB 090118 (Swift BATSS trigger, Copete et al. GCN
#8825) simultaneously in g'r'i'z'JHK with GROND (Greiner et al. 2008, PASP 120, 405)
mounted at the 2.2m MPI/ESO telescope at La Silla (Chile).
Observations started at 00:55 UT, about 11 hrs after the GRB.

Comparison to the Digital Sky Survey reveals no new sources within the Swift/BAT error circle
(Copete et al. GCN #8825). Co-added images of the first 8 minutes yield the following 5-sigma limits (in AB magnitudes):

r' > 23.2
i' > 22.5

The magnitudes are calibrated against SDSS.