the final observations was detected with an unchanging polarization angle $\theta \approx 160^{\circ}$. To date this event has become the most studied normal SN IIP.

In order to study properly any individual object, an accurate distance is required in addition to high quality observations. It is this point that is not clear for SN 1999em. There was a reasonable agreement in determining the distance to SN 1999em using the expanding photosphere method (EPM; Kirshner & Kwan [@kk74]): $7.5 \pm 0.5$ Mpc (Hamuy et al. [@hpm01]), $8.2 \pm 0.6$ Mpc (Leonard et al. [@lfg02]), and $7.838 \pm 0.331$ Mpc (Elmhamdi et al. [@edc03]). However, Leonard et al. ([@lknt03]) identified 41 Cepheid variable stars in the galaxy NGC 1637 and found that the Cepheid distance to the host galaxy was $11.7 \pm 1.0$ Mpc. This distance to SN 1999em is $\sim 50\%$ larger than the earlier EPM distance estimates. Assuming a correlation between the total $^{56}$Ni mass and the explosion energy for SNe IIP, Nadyozhin ([@n03]) evaluated the distance to the galaxy NGC 1637 of 11.08 Mpc close to the Cepheid distance. Using the spectral-fitting expanding atmosphere model (SEAM), Baron et al. ([@bnbh04]) obtained the distance to SN 1999em of $12.5 \pm 