{
  "bibcode": "2010GCN.10794....1H",
  "body": "T. Hattori and  K. Aoki (Subaru Telescope)\nreport on behalf of the Subaru GRB team:\n\nWe observed the field of GRB 100418A (Marshall et al. GCN 10612) with FOCAS\non Subaru Telescope under an excellent condition (seeing 0.3\"-0.4\"),\nstarting at 12:13 UT on May 14 2010, 25.63 days after the trigger.\nSingle exposure of 120 seconds in each V, Rc, and Ic bands was acquired.\nWe detected and resolved the host galaxy (Malesani GCN 10621), but could not\nfind any point source in the galaxy.  The host galaxy magnitudes (Vega\nsystem) are V=22.62 +-0.06, Rc=21.90 +-0.03 and Ic=21.34 +-0.05.\nRc-band magnitude is consistent with the values reported in GCN 10727\n(R=21.85 +-0.05 at 17.7 days after) and GCN 10783 (R=21.86 +-0.06 at 26.0\ndays after).\nNo time variation of R-band magnitude was thus detected during 17.7 days and\n26.0 days.\n\nWe also performed optical spectroscopy for the host galaxy starting\n12:35 UT May 14.\nWe used two settings of the spectrograph with 0.8\" width slit.\nOne was covering the wavelengths between 3900 A and 8300 A, and the other\nbetween 5800 A and 1 micron.\nThe integration time of the each setting was 1 hour (1200 seconds x 3).\nWe found strong emission-lines such as [O II], Hgamma, Hbeta, [O III]\nat z=0.624 which are same as reported in GCN 10620 and GCN 10624.\nThe continuum of the galaxy is very similar to that of the nearby blue\ncompact dwarf galaxy NGC 1140.\nWe could not identify any supernova feature like broad emission-lines\nand bumps.",
  "circularId": 10794,
  "createdOn": 1274679497000,
  "email": "nkawai@hp.phys.titech.ac.jp",
  "subject": "GRB 100418A: Subaru late-time optical imaging and spectroscopy",
  "submitter": "Nobuyuki Kawai at Tokyo Tech  <nkawai@hp.phys.titech.ac.jp>",
  "eventId": "GRB 100418A"
}