GCN Circular 9276

Subject

GRB 090426: R-band limit

Event

Date

2009-04-28T02:53:10Z (17 years ago)

From

Myungshin Im at Seoul Nat U <mim@astro.snu.ac.kr>

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

   We observed GRB090426 (Cummings et al. GCN 9254Loading...
 
 ) in R using
  the 1.0m telescope at Mt. Lemmon (Arizona, US) operated by
  the Korea Astronomy Space Science Institute.
   The R-band imaging started at 2009 April 27, 04:43:19 UT.
   The mid-point of the R-band obseravation is April 27,
  05:06:47 UT (16.3 hrs after the burst).

   From a stacked image of 6 frames (3 min exp. each),
  the afterglow is barely visible in the image where
  the R-band magnitude limit is R = 21.7 at 5-sigma. Therefore,
  we set an upper limit of the R-band magnitude to be R ~ 21.7,
  which should be close to the afterglow brightness.
   The photometry was calibrated against USNO-B1 stars in
  the vicinity of GRB.

   We thank the LOAO operator, I. Baek for her assistance for this
  observation.