Accepted..... Received....; in original form.... UBVRIJ photometry and optical spectra of the Type Ia SN 1996X obtained at ESO during a one-year-long observational campaign are presented, and supplemented by late time HST photometry. Spectroscopically, SN 1996X appears to be a ‘normal’ SN Ia. The apparent magnitude at maximum was B = 13.24 ± 0.02, and the colour B − V = 0.00 ± 0.03. The luminosity decline rate, ∆mB(15) = 1.31 ± 0.08, is close to average for a SN Ia. The best estimate of the galactic extinction is AB = 0.30 ± 0.05, and there is evidence that reddening within the parent galaxy is negligible. Detailed comparison of the light and colour curves of various ‘normal ’ SNe Ia shows that the assumption that multicolour light curves can be described simply as a one-parameter family is not perfect. Together with problems in the calibration of the templates, this may explain the discrepancies in the distance modulus derived adopting different calibrations of the absolute magnitude vs. light curve shape relations. Indeed we found that MB ranges from −19.08 to −19.48 and µ range from 32.02 to 32.4
To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.