Swift Observations of SN 2010bj in NGC 2357
ATel #2566; S. Immler (NASA/CRESST/GSFC), on behalf of the Swift satellite team
on 15 Apr 2010; 18:35 UT
Credential Certification: Stefan Immler (firstname.lastname@example.org)
Subjects: Optical, Ultra-Violet, X-ray
The Ultraviolet/Optical Telescope (UVOT) and X-Ray Telescope (XRT) on board the Swift satellite started observing the Type IIP supernova 2010bj in NGC 2357 (CBET #2230, #2232) on 2010-04-13.4 UT. The following UVOT magnitudes were measured: v = 16.0Â±0.1 (373 s exposure time), b = 16.5Â±0.1 (373 s), u = 16.6Â±0.1 (373 s), uvw1 [181-321nm] = 17.9Â±0.1 (1123 s), uvm2 [166-268nm] = 18.6Â±0.1 (2863 s), uvw2 [112-264 nm] = 18.5Â±0.1 (1877 s). These magnitudes are on the UVOT photometric system (Poole et al. 2008, MNRAS, 383, 627) which in the optical is close to the Johnson UBV. The magnitudes have not been corrected for extinction.
No X-ray source is detected at the position of the SN in the 8.1 ks Swift XRT observation obtained simultaneously with the UVOT observations. The 3-sigma upper limit to the XRT net count rate is 1.4E-03 cts/s, corresponding to an unabsorbed (0.2-10 keV band) X-ray flux of <7.3E-14 erg/cm/cm/s and a luminosity of <1.0E40 erg/s for an adopted thermal plasma spectrum with a temperature of kT = 10 keV, a Galactic foreground column density of N_H = 7E+20 (Dickey & Lockman, 1990, ARAA, 28, 215) and a distance of 34 Mpc (NED).