Related papers: UV/Optical emission from the expanding envelopes o…

We derive a simple approximate model describing the early, hours to days, UV/optical supernova emission, which is produced by the expansion of the outer <~0.01 solar mass part of the shock-heated envelope, and precedes the optical emission…

Supernova light curves are dominated at early time, hours to days, by the escape of photons from the expanding shock heated envelope. We provide a simple analytic description of the time dependent luminosity, $L$, and color temperature,…

Light emission in the first hours and days following core-collapse supernovae (SNe) is dominated by the escape of photons from the expanding shock heated envelope. In a preceding paper, Paper I, we provided a simple analytic description of…

Light emission in the first hours and days following core-collapse supernovae is dominated by the escape of photons from the expanding shock-heated envelope. In preceding papers, we provided a simple analytic description of the…

We present radiative transfer simulations for blue kilonovae hours after neutron star (NS) mergers by performing detailed opacity calculations for the first time. We calculate atomic structures and opacities of highly ionized elements (up…

We extend the approximate radiative transfer analysis of Hershkowitz, Linder, and Wagoner (1986) to a more general class of supernova model atmospheres, using a simple fit to the effective continuum opacity produced by lines (Wagoner,…

Massive stars with a core-halo structure are interesting objects for stellar physics and hydrodynamics. Using simulations for stellar evolution, radiation hydrodynamics, and radiative transfer, we study the explosion of stars with an…

Supernovae (SNe) inject $\sim 10^{51}$ erg in the interstellar medium, thereby shocking and heating the gas. A substantial fraction of this energy is later lost via radiative cooling. We present a post-processing module for the FLASH code…

The earliest supernova (SN) emission is produced when the optical depth of the plasma lying ahead of the shock, which ejects the envelope, drops below c/v, where v is the shock velocity. This "breakout" may occur when the shock reaches the…

It has been suggested that Type II supernovae with rapidly fading light curves (a.k.a. Type IIL supernovae) are explosions of progenitors with low-mass hydrogen-rich envelopes which are of the order of 1 Msun. We investigate light-curve…

We investigate the effect of the presence of lanthanides (Z = 57- 71) on the kilonova at t~hours after the neutron star merger for the first time. For this purpose, we calculate the atomic structures and the opacities for selected…

We present a systematic study of Type II supernovae (SNe II) originating from progenitors with effective temperatures ($T_{\rm eff}$) and luminosities closely resembling red supergiants (RSGs) observed in pre-SN images and in the Galaxy.…

We present a sample of 34 normal SNe II detected with the Zwicky Transient Facility, with multi-band UV light-curves starting at $t \leq 4$ days after explosion, as well as X-ray detections and upper limits. We characterize the early…

During the first few days after explosion, Type II supernovae (SNe) are dominated by relatively simple physics. Theoretical predictions regarding early-time SN light curves in the ultraviolet (UV) and optical bands are thus quite robust. We…

Assuming a spherical symmetry, the extreme UV emitted by a very hot source ionizes low pressure molecular hydrogen making a transparent bubble of H II (Protons and electrons). For an increase of radius, intensity of extreme UV and…

The first light from a supernova (SN) emerges once the SN shock breaks out of the stellar surface. The first light, typically a UV or X-ray flash, is followed by a broken power-law decay of the luminosity generated by radiation that leaks…

Early light curves of many core-collapse supernovae (SNe) are thought to be powered by the interaction of the shock wave with optically thick extended material, either a bound envelope or preexplosion ejected circumstellar matter (CSM). We…

Some fraction of the material ejected in a core collapse supernova explosion may remain bound to the compact remnant, and eventually turn around and fall back. We show that the late time (> days) power associated with the accretion of this…

The lightcurve of the explosion of a star with a radius <10-100Rsun is powered mostly by radioactive decay. Observationally such events are dominated by hydrogen deficient progenitors and classified as Type I supernovae: white dwarf…

We investigate the early-time light-curves of a large sample of 223 type II supernovae (SNe) from the Sloan Digital Sky Survey and the Supernova Legacy Survey. Having a cadence of a few days and sufficient non-detections prior to explosion,…