{
  "bibcode": "2004GCN..2601....1N",
  "body": "M. C. Nysewander, P. A. Price, D. E. Reichart, and D. Q. Lamb report on\nbehalf of the Follow-Up Network for Gamma-Ray Bursts (FUN GRB)\nCollaboration:\n\nOn April 15, 2004, we observed the location of the candidate afterglow\n(Lamb et al., GCNs 2139, 2140, 2239) of GRB 030324 (Donaghy et al., GCNs\n1954, 1955) with the LRIS instrument on the Keck I telescope in\nsimultaneous imaging mode in G and R filters.  We obtained stacked images\nof 2130 sec in G and 1805 sec in R (cut short due to instrument error)\nunder conditions of moderate humidity and seeing.\n\nUsing the standard transformation equations of Smith et al. (2002) and the\nfield calibration of Henden (GCN 1950), we calibrated the stacked images\nusing the six unsaturated stars in our field.  A source is present at the\nlocation of the candidate afterglow in both stacked images, with magnitudes\ng' = 25.29 +/- 0.09 mag and R = 25.16 +/- 0.24 mag.\n\nFirst, we rule out the possibility of a variable star.  Fitting a blackbody\n+ Galactic extinction curve model to these data, we find that log T > 3.75\nat the 3 sigma level.  This rules out flare stars (UV Cet variables), which\nare cooler than log T = 3.5.\n\nThe fitted temperature is consistent with RR Lyraes and shorter period\nCepheids, but these classes of variables stars are also ruled out, for two\nreasons:\n\n1.  RR Lyraes and Cepheids vary by less than 1.3 mag.  However, Lamb et al.\n(GCN 2239) measured a fading from i* = 23.48 +/- 0.21 mag to i* > 25.4 mag\n(2 sigma upper limit; GCN 2239).\n\n2.  To be this faint, an RR Lyrae would have to be >0.5 Mpc away and a\nCepheid would have to be >3.5 Mpc away, placing either well outside of the\nGalaxy.\n\nConsequently, we conclude that we have detected the host galaxy of GRB\n030324.  Detection of the galaxy in the G band implies that its redshift is\n<2.7.  The spectral flux distribution of the galaxy is flat, which makes\nthis a relatively blue galaxy, even for a GRB host galaxy.\n\nImages and the spectral flux distribution are available at\nwww.physics.unc.edu/~mnysewan/grb030324.html\n\nSmith et al. 2002, ApJ, 123, 2121",
  "circularId": 2601,
  "createdOn": 1084905654000,
  "email": "mnysewan@physics.unc.edu",
  "subject": "GRB 030324:  Detection and Color of Host Galaxy",
  "submitter": "Melissa Nysewander at UNC,Chapel Hill  <mnysewan@physics.unc.edu>",
  "eventId": "GRB 030324"
}