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ATEL # 1987; P. J. Brown (Penn State) and S. Immler (NASA/CRESST/GSFC) on behalf of the Swift SN team
on 23 Mar 2009; 21:35 UT
Password Certification: Peter J. Brown (firstname.lastname@example.org)
Subjects: Optical, Ultra-Violet, X-ray, Nova, Supernova, Transients
The Ultraviolet/Optical Telescope (UVOT) on board the Swift satellite started observing the type IIn Supernova 2009au in ESO 443-21 (CBET #1719,1725) at 2009-03-22.02 UT. The following UVOT magnitudes were measured: v = 17.1±0.1 (698 s exposure time), b = 17.4±0.1 (698 s), u = 16.6±0.1 (698 s), uvw1 [181-321nm] = 17.1±0.1 (1399 s), uvm2 [166-268nm] = 18.1±0.1 (1754 s), uvw2 [112-264 nm] = 18.0±0.1 (2801 s). These magnitudes are on the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) which in the optical is close to Johnson UBV, and have not been corrected for extinction.
No X-ray source is detected at the position of the SN in the 8.4 ks Swift XRT observation obtained on 2009-03-22, simultaneously with the UVOT observations. The 3-sigma upper limit to the XRT net count rate is 1.8E-03 cts/s, corresponding to an unabsorbed (0.2-10 keV band) X-ray flux of <9.5E-14 erg/cm/cm/s and a luminosity of <1.4E40 erg/s for an adopted thermal plasma spectrum with a temperature of kT = 10 keV, a Galactic foreground column density of N_H = 6.38E+20 (Dickey & Lockman, 1990, ARAA, 28, 215) and a distance of 35 Mpc (z=0.009404, Wong et al. 2006, HI Parkes All Sky Survey Final Catalog, from NED; H_o = 71 km/s/Mpc, Omega_M = 1/3, Omega_L = 2/3).