Table of Supernovae Types

illustration of the core-collapse (both pictures left) and the type Ia (both pictures right) remnants of supernovae. picture site 'Amateur Astronomy'

Type and Sub-type		Spectrum at the Maximum	Progenitors	Process	Remarks
Type I	Type Ia	hydrogen lines are absent; strong silicon lines	two white dwarfs in a binary system colliding, or a single white dwarf gorging on gases stolen from a companion star until bursting (in that case, the normal star should survive the explosion), or more triggering mechanisms	the white dwarf explodes when enough infalling material of the companion has accumulated. This explosion is of the thermonuclear type	type Ia supernovae are the cosmological "standard candles." When a Type Ia supernova explodes, the densest, hottest region within the core produces nickel 56. The radioactive decay of nickel-56 through cobalt-56 to iron-56 produces the light observed from afar. Large amounts of oxygen are a characteristic feature of white dwarfs in a binary system with a black hole. What is left over after such supernovas is either a neutron star or a black hole. Type Ia supernovas are thought to be responsible for producing most of the Universe's chromium, manganese, iron and nickel, or 'iron-peak' elements. Such supernovas are found in abundance in the Perseus cluster, located by 240 million light-years away as they also provided for our solar system valence in those elements. The Roche lobe, in a binary system where material is pouring unto one of both stars, is the limit within which orbiting material is gravitationally bound to one star or the other. A type lax would exist, with the supernova explosion moving slower and dissipating more quickly as the type would amount to about 25 in the Milky Way Galaxy. The white dwarfs generated are less dense and consisting of oxygen and neon
	Type Ib	hydrogen lines are absent; strong helium lines	more massive stars	star collapses and explodes when its fuel runs out	stars have got rid of the outer, hydrogen-rich layer before the final event
	Type Ic	hydrogen lines are absent	more massive stars	star collapses and explodes when its fuel runs out	stars have got rid of the outer, hydrogen-rich layer as of the helium layer before the final event. Type Ic supernova are thought to detonate after a massive star at about 30 solar masses, has shed or been stripped of its outer layers of hydrogen and helium. Binary stars may also be involved. Type Ics account for 20 percent of massive stars exploding from the collapse of their cores
Type II		hydrogen lines are present	masssive stars, associated with ongoing star formation. The progenitors usually live just some tens of million years	star collapses and explodes when its fuel runs out, collapses into a extraordinarily dense object in a fraction of a second and rebounds in a explosion outward	seen only in spirals galaxies. Five sub-types may be found (Type IIp supernovae -the 'p' stands for plateau- remain bright (on a plateau) for a relatively long period of time after maximum brightness). This type of supernova is dust-productor. Type IIb supernovae, as far as they are concerned, contain much less hydrogen than found in a typical supernova as astronomers believe a companion star takes most of that which surrounds the exploding main star and continues to burn as a super-hot helium star. Type II blast apart in a lopsided fashion, with the core of the star hurtling in one direction, and the ejected material mostly expanding the other way. The process by which they die causes their cores to be turbulent, boiling and sloshing around in the seconds before their demise. That sloshing leads to asymmetrical explosions. 'Type IIb stripped-envelope supernovae' are unusual because most, but not all, of the hydrogen is gone prior to the explosion. This type of exploding star was first identified in 1987 and might be related to a binary system. Type II supernovas might vary in terms of 'shock breakout,' the moment when the explosion rebound shockwave reaches to the star's surface under the form of a series of finger-like plasma jets. When those are merging, that eventually blast the star like a supernova. Smaller stars going supernova might be surrounded by gas blocking the view of the short-duration event further

Of note that a rare supernova type may be a Type Ib/Ic supernova, where the star throws away its topmost layers of hydrogen in a strong stellar wind long before it explodes. This loss explains why Type Ib/Ic spectra don’t have hydrogen lines. Type Ib/Ic supernovae are also known to produce some of the mysterious gamma-ray bursts (GRBs) which necessitate a intense, narrow jet, opening only a few degrees wide. In such a case, remains of polar jets can expand over time and form a element-rich bar of material. Supernovae with a progenitor above 8 solar masses possess noticeably higher iron temperatures than type Ia supernovae as massive stars have stronger solar winds into which the supernova expansion runs, reaching higher temperatures and imprint the remnant with more highly ionized iron atoms as type Ia supernovae occur in a cleaner environment due to their white dwarfs having less solar winds. Type Ib/c calcium-rich supernovae also exist as they are rare. Such supernovae appear outside of galaxies, have a lower luminosity compared to other supernovae, and they have a rapid evolution

A non-standard supernova, fitting nor the Type I nor II categories, is called a 'Fast-Evolving Luminous Transient,' or FELT. It consists into a giant star expelling a shell of gas and dust about a year before explosion as most of the latter's energy turns into light when it hits that previously ejected material, resulting in a short bursts of radiation. The brightening of that category of supernova just lasts only a few days, which is just 10 percent of a usual supernova