Related papers: The most massive core collapse supernova progenito…
Supernovae connected with long-duration gamma-ray bursts (GRBs) are hyper-energetic explosion resulting from the collapse of very massive stars (about 40Mo, where Mo is the mass of the Sun) stripped of their outher hydrogen and helium…
The formation of supermassive Population III stars with masses $\gtrsim$ 10,000 Msun in primeval galaxies in strong UV backgrounds at $z \sim$ 15 may be the most viable pathway to the formation of supermassive black holes by $z \sim$ 7.…
The pair instability supernova (PISN) is a common fate of very massive stars (VMSs). Current theory predicts the initial and the CO core mass ranges for PISNe of $\sim$140-260 $M_\odot$ and $\sim$65-120 $M_\odot$ respectively for stars that…
Multi-frequency observations of two radio bright SNe (SN1993J, SN1979C) carried out over a year with GMRT are presented. Their radio light curves trace the evolution of the mass loss in the stellar wind before the pre-supernova star…
The post-helium burning evolution of stars from 7 to 11 solar masses is complicated by the lingering effects of degeneracy and off-center ignition. Here stars in this mass range are studied using a standard set of stellar physics. Two…
The final collapse of the cores of massive stars can lead to a wide variety of outcomes in terms of electromagnetic and kinetic energies, nucleosynthesis, and remnants. The connection of this wide spectrum of explosion and remnant types to…
The speed of an intensity pattern of polarization currents on a circle, induced within a star by its rotating, magnetized core, will exceed the speed of light for a sufficiently large star, and/or rapid rotation, and will, in turn, generate…
Abridged - Stars with ZAMS masses between 140 and $260 M_\odot$ are thought to explode as pair-instability supernovae (PISNe). During their thermonuclear runaway, PISNe can produce up to several tens of solar masses of radioactive nickel,…
SN2006tf is the third most luminous SN discovered so far, after SN2005ap and SN2006gy. SN2006tf is valuable because it provides a link between two regimes: (1) luminous type IIn supernovae powered by emission directly from interaction with…
During the gravitational core collapse of a massive progenitor star which may give rise to at least a class of gamma-ray bursts (GRBs) associated with supernovae, a stellar core rapidly passes through a short yet important phase of…
We examine a triple-star evolution that might lead to core collapse supernovae (CCSNe) in stellar populations that are too old to allow for single or binary evolution to form CCSNe, i.e., where the most massive stars that evolve off the…
It has been argued that a substantial fraction of massive stars may end their lives without an optically bright supernova (SN), but rather collapse to form a black hole. Such an event would not be detected by current SN surveys, which are…
When a massive star ends its life, its core collapses, forming a neutron star or black hole and producing some of the most energetic explosions in the universe. Core-collapse supernovae and long-duration gamma-ray bursts are the violent…
The study of the stars that explode as supernovae used to be a forensic study, working backwards from the remnants of the star. This changed in 1987 when the first progenitor star was identified in pre-explosion images. Currently there are…
Massive stars having a CO core of $\sim$40-60 M$_\odot$ experience pulsational pair-instability (PPI) after carbon-burning. This instability induces strong pulsations of the whole star and a part of outer envelope is ejected. We investigate…
Supernova explosions of massive stars are one of the primary sites for the production of the elements in the universe. Up to now, stars with zero-age main-sequence masses in the range of 35--50~$M_\odot$ had mostly been representing the…
We review the status of the current quest to understand the mechanism of core-collapse supernovae, if neutrino-driven. In the process, we discuss the spherical explosion paradigm and its problems, some results from our new suite of collapse…
The absence of Type IIP core-collapse supernovae arising from progenitors above 17 solar masses suggests the existence of another evolutionary path by which massive stars end their lives. The direct collapse of a stellar core to a black…
The assembly of supermassive black holes poses a challenge primarily because of observed quasars at high redshift, but additionally because of the current lack of observations of intermediate mass black holes. One plausible scenario for…
The recent supernova (SN) known as SN 2009ip had dramatic precursor eruptions followed by an even brighter explosion in 2012. Its pre-2012 observations make it the best documented SN progenitor in history, but have fueled debate about the…