TITLE: GCN CIRCULAR NUMBER: 11662 SUBJECT: GRB 110206A: UVOT detection of afterglow candidate DATE: 11/02/07 17:27:08 GMT FROM: Erik Hoversten at Swift/Penn State E. A. Hoversten (PSU) and P. A. Evans (U. Leicester) report on behalf of the Swift UVOT team: We have analyzed Swift UVOT observations of the INTEGRAL-detected GRB 110206A (Mereghetti et al. et al. GCN Circ. 11654). UVOT observations began 26.9 ks after the INTEGRAL trigger. The UVOT data reveal a faint new source that does not appear in archival MAST DSS images. The refined UVOT position of the new source is: RA (J2000) 06:09:20.14 = 92.33392 (deg) Dec (J2000) -58:48:25.3 = -58.80703 (deg) with an estimated uncertainty of 0.8 arcsec (radius, 90% confidence, statistical + systematic). This position is within 0.2 arcseconds of the enhanced XRT position (Evans, GCN Circ. 11657) which is well within the measurement errors. The source is detected in the uvw1, u, and b filters, while an upper limit was found in uvm2. The observed magnitudes and 3-sigma upper limits using the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) are: Filter T_start(s) T_stop(s) Exp(s) Mag ============================================================= b 28761 29253 480 21.00 +/- 0.37 u 27847 34952 1044 20.56 +/- 0.24 uvw1 26941 34783 1771 20.36 +/- 0.26 uvm2 32977 33876 885 > 20.61 The values quoted above are not corrected for the Galactic extinction due to the reddening of E(B-V) = 0.05 in the direction of the burst (Schlegel et al. 1998).