Related papers: Supernova 2007bi as a pair-instability explosion
Observing a supernova explosion shortly after it occurs can reveal important information about the physics of stellar explosions and the nature of the progenitor stars of supernovae (SNe). When a star with a well-defined edge explodes in…
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.…
Very massive primordial stars (140 Msol < M < 260 Msol) are supposed to end their lives as PISN. Such an event can be traced by a typical chemical signature in low metallicity stars, but at the present time, this signature is lacking in the…
Blue-supergiant stars develop into core-collapse supernovae --- one of the most energetic outbursts in the universe --- when all nuclear burning fuel is exhausted in the stellar core. Previous attempts failed to explain observed explosions…
Massive Population III stars from 140 - 260 solar masses ended their lives as pair-instability supernovae (PISNe), the most energetic thermonuclear explosions in the universe. Detection of these explosions could directly constrain the…
I briefly describe the Lick Observatory Supernova Search with the 0.76-m Katzman Automatic Imaging Telescope. I then present an overview of optical observations of Type II, IIb, Ib, and Ic supernovae (SNe), all of which are thought to arise…
The recent discovery of the unusual supernova SN1998bw and its apparent correlation with the gamma-ray burst GRB 980425 has raised new issues concerning both the GRB and SNe. SN1998bw was unusually bright at maximum light and expansion…
The observation of neutrinos from Supernova 1987A has confirmed the theoretical conjecture that these particles play a crucial role during the collapse of the core of a massive star. Only one per cent of the energy they carry away from the…
Theoretical models predict that some of the first stars ended their lives as extremely energetic pair-instability supernovae (PISNe). With energies approaching 10^53 ergs, these supernovae are expected to be within the detection limits of…
Pair creation supernovae (PCSN) are thought to be produced from very massive low metallicity stars. The spectacularly bright SN 2006gy does show signatures expected from PCSNe. Here, we investigate the metallicity threshold below which PCSN…
The theory underlying the evolution and death of stars heavier than 10 Msun on the main sequence is reviewed with an emphasis upon stars much heavier than 30 Msun. These are stars that, in the absence of substantial mass loss, are expected…
Core-collapse supernovae (CCSNe) are catastrophic astrophysical phenomena that occur during the last evolutionary stages of massive stars having initial masses of around 8 M$_{\odot}$ or more. These calamitous events play a pivotal role in…
Massive stars undergoing iron core-collapse at the end of their evolution terminate their lives either in successful or failed supernovae (SNe). The physics of core-collapse supernovae (CCSNe) is complex, and their understanding requires…
Knowledge of the progenitors of core-collapse supernovae is a fundamental component in understanding the explosions. The recent progress in finding such stars is reviewed. The minimum initial mass that can produce a supernova has converged…
Supernovae of Type IIn (narrow line) appear to be explosions that had strong mass loss before the event, so that the optical luminosity is powered by the circumstellar interaction. If the mass loss region has an optical depth $>c/v_s$,…
The nebular-epoch spectrum of the rapidly declining, "transitional" type Ia supernova (SN) 2007on showed double emission peaks, which have been interpreted as indicating that the SN was the result of the direct collision of two white…
We present photometric and spectroscopic observations of supernova (SN) 2014C, primarily emphasizing the initial month after the explosion at approximately daily intervals. During this time, it was classified as a Type Ib SN exhibiting a…
We present the expected observational properties of a general relativistic instability supernova (GRSN) from the 55,500 Msun primordial (Population III) star. Supermassive stars exceeding 1e4 Msun may exist in the early Universe. They are…
We present optical photometric and spectroscopic observations of the Type~IIb supernova (SN)~2017ati. It reached the maximum light at about 27~d after the explosion and the light curve shows a broad, luminous peak with an absolute $r$-band…
Superluminous supernovae radiate up to 100 times more energy than normal supernovae. The origin of this energy and the nature of their stellar progenitors are poorly understood. We identify neutral iron lines in the spectrum of one such…