{
  "bibcode": "2007GCN..6918....1K",
  "body": "D. A. Kann, C. Hoegner & R. Filgas (TLS Tautenburg) report:\n\nWe observed the afterglow (Oksanen, GCN 6873) of GRB 071010B (Markwardt et \nal., GCN 6871) with the Tautenburg 1.34m Schmidt telescope under good \nconditions, obtaining 16 600 second images in the Rc band at 3.2 to 3.3 \ndays after the GRB. The afterglow is clearly detected in all frames. Using \ntwo USNO B1.0 stars (RA (J2000) = 10:02:09.93, Dec. (J2000) = +45:41:18.4, \nR2=16.80; RA (J2000) = 10:02:23.11, Dec. (J2000) = +45:41:41.1, R2=16.94), \nwe revise our original photometry (Kann, Hoegner & Filgas, GCN 6884) using \nfully reduced images:\n\nDate\t\tMid-Time\tRc\tdRc\n\n11.06361\t0.19848\t\t19.145\t0.041\n11.07113\t0.20600\t\t19.121\t0.033\n11.07865\t0.21352\t\t19.198\t0.030\n11.08617\t0.22104\t\t19.163\t0.062\n11.13149\t0.26637\t\t19.396\t0.032\n11.13902\t0.27389\t\t19.512\t0.223 (Clouds)\n\nUsing the same comparison stars, we derive the following magnitudes from \nour new images:\n\nDate\t\tMid-Time\tRc\tdRc\n\n14.05372\t3.18859\t20.800\t0.139\n14.06126\t3.19613\t20.815\t0.142\n14.06878\t3.20365\t20.779\t0.092\n14.07630\t3.21117\t20.852\t0.088\n14.08382\t3.21869\t20.921\t0.095\n14.09133\t3.22621\t20.899\t0.097\n14.09885\t3.23372\t20.888\t0.088\n14.10638\t3.24125\t20.839\t0.079\n14.11389\t3.24877\t20.967\t0.090\n14.12141\t3.25628\t20.946\t0.078\n14.12892\t3.26380\t21.014\t0.093\n14.13644\t3.27131\t20.929\t0.075\n14.14395\t3.27882\t20.814\t0.071\n14.15146\t3.28634\t20.732\t0.066\n14.15899\t3.29386\t20.792\t0.069\n14.16650\t3.30138\t20.864\t0.076\n\nWe note that the last data points seem to indicate a small rebrightening \nfeature which was receding again when twilight stopped our observations.\n\nWith Rc ~ 20.9 at 3.2 days after the GRB, the afterglow is among the \nbrightest observed so far (Kann, Klose & Zeh 2006, ApJ, 641, 993; Kann et \nal., in preparation). Using data from Arto Oksanen \n(http://murtoinen.dyndns.org/ccd/grb/grb071010/) and Im, Lee & Urata (GCN \n6897), we find that the afterglow can be fit with a broken power law with \npre-break slope alpha_1 = 0.3 +/- 0.083, post-break slope alpha_2 = 0.575 \n+/- 0.009, and break time t_b = 0.049 +/- 0.019 days. The very shallow \ndecay (Kann, Hoegner & Filgas, GCN 6884, Templeton et al., GCN 6903) is \nthus seen to continue, which is highly unusual.\n\nFurther observations are planned and encouraged at other facitlities.\n\nThis message may be cited.\n\n[GCN OPS NOTE(16oct07):  Per author's request, the typo in the first line\nwas changed from \"071013\" to \"071010B\".]",
  "circularId": 6918,
  "createdOn": 1192480874000,
  "email": "kann@tls-tautenburg.de",
  "subject": "GRB 071010B: TLS 2nd Epoch, refined analysis",
  "submitter": "Alexander Kann at TLS Tautenburg  <kann@tls-tautenburg.de>",
  "eventId": "GRB 071010B"
}