Type Ia supernova

A type Ia supernova is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white dwarf. Physically, carbon-oxygen white dwarfs with slow rotation are limited to below 1.44 solar masses.

Since type Ia supernovae have a known brightness they can be used as standard candles to determine the distance to a galaxy once the stretch-factor is accounted for.

When a runaway thermonuclear explosion rips through a white dwarf star and blows the star to bits, it is called a type 1a supernova. These explosions are incredibly violent and incredibly bright, sometimes outshining entire galaxies.

Type I (especially Ia) supernova create most of the iron and nickel found in the interstellar medium. Type 1a supernovae are several times more luminous than type Ib, Ic, and type II supernovae. They leave no core remnant behind, and happen when a low-mass star's core remnant (a white dwarf) detonates.

Type Ia Supernova Media

At the core of a planetary nebula, Henize 2-428, two white dwarf stars slightly under one solar mass each are expected to merge and create a Type Ia supernova destroying both in about 700 million years (artist's impression).
Spectrum of SN 1998aq, a type Ia supernova, one day after maximum light in the B band
G299 Type Ia supernova remnant.
Supernova remnant N103B taken by the Hubble Space Telescope.
This plot of luminosity (relative to the Sun, L0) versus time shows the characteristic light curve for a Type Ia supernova. The peak is primarily due to the decay of nickel (Ni), while the later stage is powered by cobalt (Co).
Light curve for type Ia SN 2018gv
Supernova remnant SNR 0454-67.2 is likely the result of a Type Ia supernova explosion.