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ATEL # 1053; S. Immler (NASA/USRA/GSFC) and P. J. Brown (PSU) on behalf of the Swift satellite team
on 13 Apr 2007; 21:49 UT
Password Certification: Stefan Immler (firstname.lastname@example.org)
Subjects: Optical, Ultra-Violet, X-ray, Nova, Supernova
Swift Ultraviolet/Optical Telescope (UVOT) and X-Ray Telescope (XRT) started observing the type IIn SN 2007bb (CBET #912, CBET #916) on 2007-04-10.0 UT. A second observation started on 2007-04-13.0 UT and was truncated due to a GRB, leading to UVOT data in the B, U, and UVW1 filters only. The following UVOT magnitudes were measured for these two epochs: V = 17.5, (308 s exposure times), B = 17.9, 17.9 (308 s, 80 s), U = 17.2, 17.7 (308 s, 80 s), UVW1 [181-321nm] = 18.3, 18.7 (613 s, 896 s), UVM2 [166-268 nm] = 19.5, (843 s), and UVW2 [112-264 nm] = 19.4, (1231 s, 161 s). Statistical and systematic errors are 0.1 each. The magnitudes have not been corrected for extinction.
No X-ray source is detected at the position of the SN in the merged 4.3 ks XRT observation obtained simultaneously. The 3-sigma upper limit to the XRT net count rate is 2.8 E-03 cts/s, corresponding to an unabsorbed (0.2-10 keV band) X-ray flux and luminosity of < 1.6 E-13 ergs/cm/cm/s and < 1.2 E41 ergs/s, respectively, for an adopted thermal plasma spectrum with a temperature of kT = 10 keV, a Galactic foreground column density of N_H = 6.9E+20 (Dickey & Lockman, 1990, ARAA 28, p215) and a distance of 89 Mpc (z=0.020858, NED; H_o = 71 km/s/Mpc, Omega_M = 1/3, Omega_L = 2/3).