We demonstrate the applicability of our new method (the Dense Shell Method or DSM) for the determination of astronomical distances by calculating the distance to SN2009ip. The distance to this supernova has been accurately determined in the standard
approach via the cosmic distance ladder and has been found to be 20.4 Mpc. Our direct method, assuming the most reasonable parameter values, gives a very close result, namely 20.1+/-0.8 (68% CL) Mpc to SN2009ip.
Shock breakout is the brightest radiative phenomenon in a Type II supernova (SN). Although it was predicted to be bright, the direct observation is difficult due to the short duration and X-ray/ultraviolet-peaked spectra. First entire observations of
the shock breakouts of Type II Plateau SNe (SNe IIP) were reported in 2008 by ultraviolet and optical observations by the {it GALEX} satellite and supernova legacy survey (SNLS), named SNLS-04D2dc and SNLS-06D1jd. We present multicolor light curves of a SN IIP, including the shock breakout and plateau, calculated with a multigroup radiation hydrodynamical code {sc STELLA} and an evolutionary progenitor model. The synthetic multicolor light curves reproduce well the observations of SNLS-04D2dc. This is the first study to reproduce the ultraviolet light curve of the shock breakout and the optical light curve of the plateau consistently. We conclude that SNLS-04D2dc is the explosion with a canonical explosion energy $1.2times10^{51}$ ergs and that its progenitor is a star with a zero-age main-sequence mass $20M_odot$ and a presupernova radius $800R_odot$. The model demonstrates that the peak apparent $B$-band magnitude of the shock breakout would be $m_{rm B}sim26.4$ mag if a SN being identical to SNLS-04D2dc occurs at a redshift $z=1$, which can be reached by 8m-class telescopes. The result evidences that the shock breakout has a great potential to detect SNe IIP at $zgsim1$.
