GCN Circular 9244
Subject
GRB090423: Y-band limit
Date
2009-04-25T04:12:16Z (15 years ago)
From
Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>
M. Im, C. Choi, Y. Jeon, W. Park, I. Lee (Seoul National Univ),
Y.-B. Jeon (KASI) and Y. Urata (NCU) on behalf of EAFON team.
We took a series of Y-band images of GRB090423 using the 1.0m
telescope at Mt. Lemmon (Arizona, US) operated by the Korea Astronomy
Space Science Institute.
We do not detect the afterglow in a stacked image with the
total exposure time of 78 min, placing an upper limit of Y < 19.8 (Vega)
at 3-sigma at the mid point of UT April 24, 06:16. The photometry
calibration was done using the calibration data reported
in Im et al. (GCN 9242, 9221).
We thank the LOAO operator, J. Yoon for his assistance for this
observation.