On the central black hole mass in Mkn 501

CCD photometry is presented of the type Ia SN 2001V occurred in the edge-on spiral galaxy NGC 3987. The observations made through Johnson-Cousins BVRI filters were collected from Feb. 24 ( t = - 8 days, with respect to B-maximum), up to May 5 ( t = +62 days). The light curves are analyzed with the revised Multi-Colour Light Curve Shape (MLCS) method (Riess et al. 1998) by fitting template vectors to the observed light curves simultaneously. The reddening of SN 2001V is estimated to be E(B-V)=0.05 mag, while the galactic component is E(B-V) = 0.02 mag (Schlegel et al. 1998), suggesting that part of the reddening may be due to the ISM in the host galaxy. The (delta) parameter in MLCS converged to -0.47 mag, indicating that this SN was overluminous relative to the majority of Type Ia SNe. The inferred distance to its host galaxy, NGC 3987, is 74.5+-5 Mpc, which is in good agreement with recently determined kinematic distances, based on radial velocity corrected for Virgo-infall and Hubble constant H0 = 65 km s^-1 Mpc^-1.