GCN Circular 9143
Subject
GRB 090417B: MITSuME Okayama optical upper limits
Date
2009-04-18T06:21:01Z (15 years ago)
From
Michitoshi Yoshida at Okayama Astrophysical Obs <yoshida@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 090417B (Sbarufatti et al. GCN 9135)
with optical three color (g', Rc and Ic) CCD camera attached to
the MITSuME 50cm telescope of Okayama Astrophysical Observatory.
We started the observation at 15:29:29 UT, 566s after the burst.
There is no point source brighter than 20 mag within the XRT error
circle (Cummings et al. GCN 9139) in our 5940 sec exposure frames.
3-sigma upper limits to our observation are listed below.
We used GSC2.3 catalog for flux calibration.
Mid-UT Td EXP-T g' Rc Ic
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15:34:43 880s 540s (9x60s) >19.2 >18.8 >18.4
15:44:55 1492s 1560s (24x60s) >19.9 >19.6 >19.1
15:59:37 2374s 3000s (50x60s) >20.2 >19.9 >19.4
16:29:42 4179s 5940s (99x60s) >20.3 >20.0 >19.5
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