GCN Circular 10405
D. Grupe (PSU) reports on behalf of the Swift-XRT team: We have analyzed 1.9 ks of XRT data for GRB 100212A (Grupe et al. GCN Circ. 10401), from 64 s to 7 ks after the BAT trigger. The data comprise 409 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 10403). The light curve is complicated displaying several strong flares up to 700s after the burst. The underlying afterglow light curve suggests a step decay slope of alpha=2.89+/-0.09. However, the data of the second orbit indicate the beginning of the plateau phase with a significantly flatter decay slope. Predictions of the further development of the X-ray light curve are not reliable at this point. A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 2.03 (+/-0.03). The best-fitting absorption column is 1.97 (+/-0.08) x 10^21 cm^-2, in excess of the Galactic value of 1.3 x 10^21 cm^-2 (Kalberla et al. 2005). The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 3.8 x 10^-11 (5.6 x 10^-11) ergs cm^-2 count^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00412081. This circular is an official product of the Swift-XRT team.