Two groups recently deduced the positive value for the cosmological constant, concluding at a high (≥ 99%) confidence level that the Universe should be accelerating. This conclusion followed from the statistical analysis of dozens of high-redshift supernovae. In this paper this conclusion is discussed. From the conservative frequentist’s point of view the validity of null hypothesis of the zero...

Aims. Powerful gravitational telescopes in the form of massive galaxy clusters can be used to enhance the light collecting power over a limited field of view by about an order of magnitude in flux. This effect is exploited here to increase the depth of a survey for lensed supernovae at near-IR wavelengths. Methods. We present a pilot supernova search programme conducted with the ISAAC camera at...

CCD BV RI photometry is presented for two type Ia supernovae 2000E and 2001V, for SN Ib 2001B and SN II-P 2001X. The parameters of light curves and absolute magnitudes at maximum light are estimated. It is shown that all four supernovae are typical for their classes considering the shape of their light curves and maximum luminosity.

The discovery of the extremely luminous supernova SN 2006gy, possibly interpreted as a pair instability supernova, renewed the interest in very massive stars. We explore the evolution of these objects, which end their life as pair instability supernovae or as core collapse supernovae with relatively massive iron cores, up to about 3M⊙.

The derivation of the ponderomotive force due to neutrinos by Hardy and Melrose [Phys.Rev.D 54, 6491 (1996)] is based on a flawed analysis of the ponderomotive force concept. Their conclusions also contain an erroneous physical assumption related to the neutrino emission in supernovae. A correct analysis shows the importance of the ponderomotive force due to neutrinos in type II supernovae expl...