Photometry is the most easily acquired information about supernovae. The light curves constructed from regular imaging provide signatures not only for the energy input, the radiation escape, the local environment and the progenitor stars, but also for the intervening dust. They are the main tool for the use of supernovae as distance indicators through the determination of the luminosity. The li...

There are hints that nearby Type Ia supernovae may be a little different than those at large redshift. Confidence in the conclusion that there is a cosmological constant and an accelerating Universe thus still requires the hard work of sorting out potential systematic effects. Polarization data show that core-collapse supernovae (Type II and Ib/c) probably depart strongly from spherical symmetr...

A number of supernovae, classified as Type II, show remarkably peculiar properties such as an extremely low expansion velocity and an extraordinarily small amount of Ni in the ejecta. We present a joint analysis of the available observations for two of these peculiar Type II supernovae, SN 1997D and SN 1999br, using a comprehensive semi-analytic method that can reproduce the light curve and the...

A new, fully dynamic and self-consistent radiation hydrodynamics code, suitable for the calculation of supernovae light curves and continuum spectra, is described. It is a multigroup (frequency-dependent) code and includes all important O(v/c) effects. It is applied to the model W7 of Nomoto, Thielemann, & Yokoi (1984) for supernovae of type Ia. Radioactive energy deposition is incorporated thr...

We use time-dependent, axisymmetric, hydrodynamic simulations to study the linear stability of the stalled, spherical accretion shock that arises in the post-bounce phase of core-collapse supernovae. We show that this accretion shock is stable to radial modes, with decay rates and oscillation frequencies in close agreement with the linear stability analysis of Houck and Chevalier. For non-spher...

We investigate the nucleosynthesis of the radionuclide Fe in electron-capture supernovae (ECSNe). The nucleosynthetic results are based on a self-consistent, two-dimensional simulation of an ECSN as well as models in which the densities are systematically increased by some factors (low-entropy models). Fe is found to be appreciably made in neutron-rich ejecta during the nuclear quasiequilibrium...

We show that the ”puzzling” chemical composition observed in the extremely metal poor star HE0107-5240 may be naturally explained by the concurrent pollution of at least two supernovae. In the simplest possible model a supernova of quite low mass (∼ 15 M⊙), underwent a ”normal” explosion and ejected ∼ 0.06 M⊙ of Ni while a second one was massive enough (∼ 35 M⊙) to experience a strong fall back...

We investigate the effects of neutrino-nucleus interactions (the ν-process) on the production of iron-peak elements in Population III core-collapse supernovae. The ν-process and the following proton and neutron capture reactions produce odd-Z iron-peak elements in complete and incomplete Si burning region. This reaction sequence enhances the abundances of Sc, Mn, and Co in the supernova ejecta....

We present BVRI photometry of the Type Ia supernovae 1999da, 1999dk, 1999gp, 2000bk, and 2000ce, plus infrared photometry of three of these. These objects exhibit the full range of decline rates of Type Ia supernovae. Combined optical and infrared data show that families of V − infrared color curves can be used to derive the host extinction (AV ) of these objects. Existing data do not yet allow...

We consider the simultaneous chemical, photometric, and gaseous thermal energy evolution of elliptical galaxies. The evolution of chemical abundances in the intracluster medium (ICM) is set by the differing timescales for gas ejection, via supernovae (SNe)driven winds, from dwarf, normal, and giant ellipticals, and is monitored concurrently. Emphasis is placed upon the influence of, and sensiti...