TITLE: GCN CIRCULAR NUMBER: 6669 SUBJECT: GRB 070724B: Swift-XRT afterglow candidates DATE: 07/07/25 23:50:43 GMT FROM: Pat Romano at OAB-Swift P. Romano(Uni-Bicocca and OAB), J.A. Kennea(PSU), C. Guidorzi(Uni-Bicocca and OAB), D. Burrows(PSU) report on behalf of the Swift-XRT team: We have analysed the first two orbits of Swift-XRT data obtained for GRB 070724B detected by SuperAGILE (Feroci et al., GCN Circ. 6668), which include 3971s of Photon Counting (PC) mode data, beginning on 2007-07-25 18:32:39 UT, 19.1 hours after the burst trigger time. Using the PC data we found two sources within the SuperAGILE error circle, at the following positions: 1) RA, Dec=17.48574, 57.67613, which is equivalent to RA(J2000) = 01 09 56.58 Dec(J2000) = +57 40 34.1 with an estimated error radius of 4.5 arcsec (90% confidence). This position lies 4.6 arcmin from the SuperAGILE position (GCN Circ. 6668). The current observed 0.3-10 keV count rate is (3.9+/-0.4)E-02 counts/s, which translates into a 0.3-10 keV flux of ~2E-12 erg/cm2/s (assuming a power-law with photon index=2 absorbed by a column of NH=E21 cm-2). 2) RA, Dec= 17.51024, 57.81898, which is RA(J2000) = 01 10 02.46 Dec(J2000) = +57 49 08.3 with an estimated error radius of 6.1 arcsec (90% confidence). This position lies 9.5 arcmin from the SuperAGILE position. The current observed 0.3-10 keV count rate is (0.6+/-0.2)E-02 counts/s, which translates into a 0.3-10 keV flux of ~3E-13 erg/cm2/s. More data are being collected and a new circular will be issued when the fading nature of these objects is established. This circular is an official product of the XRT team. [GCN OPS NOTE(26jul07): Per author's request, DB's affiliation was added, "17.1 hours" was changed to "19.1 hours", and the exponent of the count rate in the second source changed from "03" to "02".]