GCN Circular 8605
B. Sbarufatti, V. La Parola, V. Mangano (INAF-IASF Pa) report on behalf of the Swift-XRT team: Swift began observing the field of the Swift BAT Slew Survey (BATSS) GRB 081203B (Copete et al., GCN Circ. 8600, 8602) 16.7 ks after the trigger. Using 1419 s of XRT Photon Counting mode data we detect a single uncatalogued source inside the BAT error circle. Using the XRT data and 2 UVOT images, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 228.7993, 44.4284 which is equivalent to: RA (J2000): 15 15 11.83 Dec (J2000): +44 25 42.3 with an uncertainty of 1.8 arcsec (radius, 90% confidence). The source lies 27 arcsec from the BAT centroid and has a count rate of ~5.5e-1 counts/s during this observation. It is not possible to determine whether this source is fading given the current statistics. Further observations are ongoing to clarify the nature of this source. This circular is an official product of the Swift-XRT team.