TITLE:   GCN CIRCULAR
NUMBER:  9207
SUBJECT: GRB090423, RIMOTS optical upper limits
DATE:    09/04/23 14:00:54 GMT
FROM:    Kenta Kono at Miyazaki U  <kenta0514@astro.miyazaki-u.ac.jp>

K.Kono, K.Noda, E.Sonoda, N.Ohmori, H.hayasi,
A.Daikyuji, Y.Nisioka, M.Yamauchi
(University of Miyazaki)

We have observed the field covering the error circle of
GRB090423 (Swift trigger 350184, GCN 9198, H. A. Krimm et al.)
with the unfiltered CCD camera on the 30-cm telescope
at University of Miyazaki.
The observation was started 10:49:54 UT, about 3.0 hr
after the Swift trigger time.

We have compared our data of 30 sec exposures
with the USNO-A2.0 catalog,
There is no new source at the reported position.
(GCN 9198, H. A. Krimm et al. GCN 9202, N. Tanvir et al.
GCN 9204, D. M. Palmer et al. GCN 9205, P. A. Evans et al. )

the upper limits are as follows:
--------------------------------------------------------------
Start(UT) End(UT) Num. of frames Limit (mag.)
--------------------------------------------------------------
10:49:54 10:50:24 1 16.5
10:49:54 11:45:01 45 19.4
---------------------------------------------------------------