TITLE:   GCN CIRCULAR
NUMBER:  9242
SUBJECT: GRB 090423: Y-band field calibration update/correction
DATE:    09/04/25 02:31:03 GMT
FROM:    Myungshin Im at Seoul Nat U  <mim@astro.snu.ac.kr>

  M. Im, Y. Jeon, C. Choi, W. Park, I. Lee Seoul National Univ),
  Y.-B. Jeon (KASI) and Y. Urata (NCU) on behalf of EAFON team.

  The Y-band calibration data reported earlier by Im et al.
  (GCN 9221) have been updated with a revised zero point,
  and the catalog now includes more objects.

  The updated field calibration data are available
  at the same location as before:

  http://astro.snu.ac.kr/~mim/grb/readme
  http://astro.snu.ac.kr/~mim/grb/grb090423_ycal.dat
  http://astro.snu.ac.kr/~mim/grb/yobj.reg
  http://astro.snu.ac.kr/~mim/grb/chart.gif

  We thank the LOAO operator, J. Yoon for his assistance for this
  observation.