The source of the large amounts of dust observed in high redshift galaxies has remained uncertain for nearly 40 years. Despite the success of models in producing dust within supernova explosions, only a handful of supernovae show direct observational evidence for dust condensation, and these examples all yield 2-3 orders of magnitude less dust than predicted by the models. Recent observations s...

Aims. We present spectra of six Type Ia and two Type II supernovae obtained in June 2002 at the William Herschel Telescope during a search for Type Ia supernovae (SN Ia) at intermediate redshift. Methods. Supernova type identification and phase determination are performed using a fitting technique based on a χ2 minimization against a series of model templates. Results. The spectra range from z ...

Type Ia supernovae (SN Ia) have provided the first evidence for an accelerating universe and for the existence of an unknown “dark energy” driving this expansion. The 5-year Supernova Legacy Survey (SNLS) will deliver ∼700 type Ia supernovae and as many type II supernovae with wellsampled light curves in 4 filters g′, r′, i′ and z′. The current status of the project will be presented, along wit...

We derive constraints which must be satisfied by the sources of ∼ 1015 to ∼ 1018 eV cosmic rays, under the assumption that the sources are Galactic. We show that while these constraints are not satisfied by ordinary supernovae, which are believed to be the sources of . 1015 eV cosmic rays, they may be satisfied by the recently discovered class of trans-relativistic supernovae (TRSNe), supernova...

The observation of distant supernovae shows that the light of supernovae Ia is dimmer than it would be in a decelerating Universe. Several effects might be responsible for this phenomenon: cosmological constant, evolution of supernovae, selection bias, gravitational lensing, intergalactic dust, and influence of inhomogeneous distribution of matter on light propagation. All these effects but the...

Novae and supernovae are among the most violent explosive events known in nature. They can arise in two ways: from single star evolution, as Type II supernovae; or from binary star evolution, as novae and Type Ia Supernovae. The possible evolutionary link between the two latter classes will be addressed, together with some major results from multiwavelength observations of SN 1987A and of recen...

In this article, a broad perspective of supernovae, their classification and mechanism is given. Later, the astrophysical significance of supernovae is discussed in brief.

We examine the efficiency with which supernova-enriched gas may be ejected from dwarf disk galaxies, using a methodology previously employed to study the self-enrichment efficiency of dwarf spheroidal systems. Unlike previous studies that focused on highly concentrated starbursts, in the current work we consider discrete supernova events spread throughout various fractions of the disk. We model...