GCN Circular 9242
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.