[AAVSO-HEN] GRB 090401B: Upper limits of MITSuME optical observation

[grb at aavso.org]

The following is a GCN Circular circulated via the AAVSO network.
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TITLE:   GCN CIRCULAR
NUMBER:  9080
SUBJECT: GRB 090401B: Upper limits of MITSuME optical observation
DATE:    09/04/02 13:49:37 GMT
FROM:    Michitoshi Yoshida at Okayama Astrophysical Obs  <yoshida at oao.nao.ac.jp>

D. Kuroda, M. Yoshida, K. Yanagisawa, Y. Shimizu, S. Nagayama,
H. Toda (OAO, NAOJ) and N. Kawai (Tokyo Tech) report on behalf
of the MITSuME collaboration:

We observed the field of GRB 090401B (Schady et al. GCN 9066)
with optical three color (g', Rc and Ic) CCD camera attached to
the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
We did not detect the optical afterglow reported by Schady and
Oates (GCN 9067; GCN 9074). 3-sigma upper limits to our
observation are listed below. We used GSC2.3 catalog for flux
calibration.

       Mid-UT         T(s)   EXP(s)      g'      Rc     Ic
-------------------------------------------------------------
2009-04-01 10:43:51   7706     660     >18.2   >18.1  >17.6
-------------------------------------------------------------