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 \pm 0.02 , and the colour B - V = 0.00 \pm 0.03 .
The luminosity decline rate , \Delta m _ { B } ( 15 ) = 1.31 \pm 0.08 , is close to average for a SN Ia .
The best estimate of the galactic extinction is A _ { B } = 0.30 \pm 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 M _ { B } ranges from -19.08 to -19.48 and \mu range from 32.02 to 32.48 depending on the method used [ 1996a , 1999 , 1998a ] .

Computations of model light curve and synthetic spectra for both early- and late-times , confirm that 1996X is a normal Type Ia SN and that a satisfactory fit can be obtained using a W7 progenitor structure only if we adopt the short distance .
A larger distance would imply a too large Ni mass for this fainter than average SNIa .