SN 1972E

SN 1972E was a Type Ia supernova discovered in 1972 in the galaxy NGC 5253. Its well-observed light curve helped establish Type Ia supernovae as tools for measuring cosmic distances and expansion.

Connect

NGC 5253: NGC 5253 is a nearby dwarf galaxy in the constellation Centaurus, known for intense star formation. SN 1972E exploded in this galaxy, whose proximity enabled unusually detailed observations.
Type Ia supernova: A stellar explosion powered by the thermonuclear disruption of a white dwarf in a binary system. SN 1972E belongs to this supernova class, whose luminosities can be standardized.
Hubble constant: The present-day rate of expansion of the universe, relating recession speed to distance on large scales. SN 1972E helped calibrate supernova distances used in historical measurements of this rate.
White dwarf: A compact stellar remnant supported against gravity by electron degeneracy pressure. A white dwarf is the star whose thermonuclear disruption produces a Type Ia event like SN 1972E.
SN 1987A: SN 1987A was a supernova in the Large Magellanic Cloud, observed in 1987. Like SN 1972E, it became a landmark nearby event studied across many wavelengths.
Light curve: A graph of an astronomical object's brightness over time. SN 1972E's detailed rise and decline helped connect its peak brightness to its fading rate.
Hubble tension: The discrepancy between measurements of the Hubble constant from the nearby universe and the early universe. Its distance-ladder legacy belongs to the local measurement side of this unresolved discrepancy.
Thermonuclear runaway: A self-amplifying nuclear-burning episode in which rising temperature accelerates further energy release. Runaway carbon burning powers the explosion that produced SN 1972E.
SN 1991T: SN 1991T was an unusually luminous Type Ia supernova with distinctive spectral features before maximum brightness. Its atypical properties show that Type Ia events do not all match SN 1972E's standard pattern.
Phillips relation: An empirical relation between a Type Ia supernova's peak luminosity and its post-maximum decline rate. SN 1972E contributed early evidence that light-curve shape can standardize supernova luminosities.