Supernova 2005dn

The ninth SN found by BRASS was SN 2005dn, in galaxy NGC 6861F. This SN was discovered on August 27.03 UT through CCD images obtained at CEAMIG-REA Observatory at Belo Horizonte, Brazil, and confirmed through IAUC 8589, dated August 28.

NGC 6861F is a edge-on spiral galaxy whose morphological class is still under discussion, varying from Sc (Simbad/CDS database) to SBdm (NED database). The galaxy is located at R.A. 20^o11'11.8" , Dec -48^o16'33" (2000.0), with apparent dimensions of 1.6 x 0.3 arcmin. The offset of SN 2005dn from the center of NGC 6861F was measured as 0".2 E, 5".6 S. The galaxy's recession speed (3186 km/s) and redshift (0.01063), both from NED's data, indicate a distance of about 45.5 Mpc, or some 148 million light-years, given a Hubble constant of 70 km/s.Mpc. Assuming that distance as true, and given our measured apparent magnitude of 15.0 for the supernova, we can estimate its absolute magnitude as -18.3, which seems quite typical of a recent explosion.