Type Ia supernovae

Definition

A Type Ia supernova is a powerful and luminous stellar explosion resulting from the thermonuclear disruption of a white dwarf in a binary system. It occurs when the white dwarf accretes matter from its companion star, reaching the Chandrasekhar limit and igniting carbon fusion uncontrollably.

5 Must Know Facts For Your Next Test

1. Type Ia supernovae are essential standard candles for measuring cosmic distances due to their consistent peak luminosity.
2. They occur exclusively in binary star systems where one of the stars is a white dwarf.
3. The Chandrasekhar limit, approximately 1.4 solar masses, is critical for triggering a Type Ia supernova.
4. Type Ia supernovae play a significant role in enriching the interstellar medium with heavy elements like iron.
5. These supernovae exhibit no hydrogen lines in their spectra, distinguishing them from other types of supernovae.

Review Questions

• What triggers a Type Ia supernova in a binary star system?
• Why are Type Ia supernovae used as standard candles in astrophysics?
• How does the spectrum of a Type Ia supernova differ from other types of supernovae?

Related terms

Chandrasekhar Limit: The maximum mass (about 1.4 times that of the Sun) that a white dwarf can have before undergoing collapse or explosion.

White Dwarf: A small, dense remnant of a low- or medium-mass star that has exhausted its nuclear fuel and expelled its outer layers.

Binary Star System: A stellar system consisting of two stars orbiting around their common center of mass.