GCN Circular 3602
K. Page, S. Vaughan, M. Goad (Leicester), D. N. Burrows (PSU), M. Ajello (MPE), R. Fink and N. Gehrels (GSFC) report on behalf of the Swift XRT team: We have analysed the first two orbits of data for GRB050713b (GCN 3590, Vaughan et al., 2005). Using xrtcentoid, the refined position is: RA(J2000) = 20h 31m 15.5s Dec(J2000) = +60d 56' 40.4" with an uncertainty of 6 arcsec. This is only 2 arcsec from the original XRT position (GCN 3590, Vaughan et al., 2005). The light-curve shows a steeply fading afterglow during the first orbit, with a decay slope of alpha = 2.88 +/- 0.12 between 143 and 600 seconds after the trigger. After ~5000 seconds (i.e. on the second orbit), the light-curve flattens significantly; more data are required to constrain the slope following the break in the light curve. The WT spectrum can be fitted by an absorbed power-law with a spectral index, Gamma = 1.70 +0.11/-0.09 and excess NH of (1.97 +0.50/-0.43)e21 cm^-2. The unabsorbed 0.3-10 keV flux (averaged over 143 and 330 seconds after the burst) is (9.02 +0.16/0.80)e-10 erg cm^-2 s^-1.