Synthetic magnitudes of spectra. B_max is taken to have been 18 days after explosion. The spectra ARE corrected for extinction or heliocentric redshift and so these should be compared to theoretical magnitudes. I have corrected through to the day 98 spectrum to make the spectra agree with a fit to Bruno's template. The zdaya spectra have have the correction for extinction and redshift. The day 732 spectrum was obtained by scanning from Kirshner & Oke (1975) and so the value for day 732 are especially suspect which is too bad because they are vitally important. Note none of the U magnitudes are from good coverage of the U band. Thus these U's are probably pretty poor. Omit altogether 7 34.0 .000 1 .000 1 12.029 1 9.542 1 9.304 0 Synthetic magnitudes of spectra. No. t(days) U B V R I 1 22.0 8.280 1 8.399 0 8.295 0 8.331 0 8.714 0 2 23.0 8.299 1 8.425 0 8.346 0 8.471 0 8.919 0 3 24.0 8.276 1 8.451 0 8.412 0 8.594 0 9.046 0 4 27.0 8.703 1 8.699 0 8.532 0 8.741 0 9.135 0 5 29.0 8.914 1 8.801 0 8.726 0 8.905 0 9.027 0 6 30.0 9.175 1 9.032 0 8.668 0 8.879 0 9.090 0 8 38.0 10.149 1 9.931 0 9.166 0 9.074 0 9.094 0 9 41.0 10.417 1 10.210 0 9.375 0 9.342 0 9.398 0 10 44.0 10.593 1 10.462 0 9.566 0 9.325 0 9.194 0 11 53.0 11.241 1 11.025 0 10.056 0 9.934 0 9.642 0 12 62.0 11.634 1 11.280 0 10.399 0 10.284 0 10.196 0 13 73.0 11.818 1 11.465 0 10.682 0 10.512 0 10.515 0 14 76.0 11.683 1 11.459 0 10.811 0 10.685 0 10.736 0 15 98.0 13.024 1 11.910 1 11.296 0 11.234 0 11.356 0 16 222.0 18.346 1 13.804 1 13.586 0 14.388 0 14.508 0 17 253.0 15.504 1 14.286 0 14.204 0 15.032 0 15.039 0 18 365.0 17.440 1 16.014 0 15.966 0 16.768 0 16.022 0 19 434.0 17.296 1 17.083 0 17.026 0 17.657 0 16.577 1 20 732.0 23.378 1 20.641 1 21.970 1 .000 1 .000 1 0 means everything is OK. 1 means the spectrum did not cover the whole passband.