[vsnet-grb-info 7520] GRB090401B, RIMOTS optical upper limits

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  9079
SUBJECT: GRB090401B, RIMOTS optical upper limits
DATE:    09/04/02 05:17:04 GMT
FROM:    Kenta Kono at Miyazaki U  <kenta0514 at 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
GRB090401B (Swift trigger 348152, GCN 9066, Schady et al.) 
with the unfiltered CCD camera on the 30-cm telescope 
at University of Miyazaki.
The observation was started 10:47:10 UT, about 1.8 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 9068, Stamatikos et al. GCN 9070, Osborne et al. )

the upper limits are as follows:
--------------------------------------------------------------
Start(UT)   End(UT)    Num. of frames    Limit (mag.)
--------------------------------------------------------------
11:41:47    11:42:17          1            16.8
11:41:47    12:32:21         43            17.7
---------------------------------------------------------------