Are Type Ia perfectly standard?

No—intrinsic scatter exists; cosmology uses empirical corrections and often Cepheid-calibrated ladders.

What about Type Ib/c or superluminous events?

Many other classes exist; this page highlights the Ia vs II-P pedagogical contrast only.

Supernova Light Curves

Schematic Ia rise/decay vs II-P plateau; standard-candle note.

About this model

Supernova light curves encode explosion physics. Type Ia events—thermonuclear disruptions of carbon–oxygen white dwarfs near the Chandrasekhar mass—show a fast rise, a peak, then a decline powered largely by ⁵⁶Ni → ⁵⁶Co decay; after calibration (stretch, color) they anchor cosmological distances. Type II supernovae arise from core collapse of massive stars; II-P shows a plateau from hydrogen recombination before a radioactive tail. The curves here are analytic teaching shapes, not fits to SNfactory, CfA, or Pan-STARRS light curves.

Who it's for: Astrophysics overview after HR diagrams; pairs with cosmic distance ladder and cosmology pages.

Key terms

Type Ia supernova
Type II-P
Light curve
Standard candle
Nickel decay
Core collapse
Plateau

How it works

Type Ia supernovae (thermonuclear disruption of a white dwarf near the Chandrasekhar limit) show a fast rise, a peak, then a decline powered largely by ⁵⁶Ni decay—empirically usable as standardizable candles after stretch/color corrections. Type II (core collapse) are diverse; II-P shows a plateau from extended hydrogen recombination before a slower tail. This page draws schematic analytic shapes for lectures, not Bolometric fits to individual events.

Key equations

Standard candle: m = M + 5 log₁₀(d_L/10 pc) after calibration — real Ia need SALT2/Tripp-style terms

Frequently asked questions

Are Type Ia perfectly standard?: No—intrinsic scatter exists; cosmology uses empirical corrections and often Cepheid-calibrated ladders.
What about Type Ib/c or superluminous events?: Many other classes exist; this page highlights the Ia vs II-P pedagogical contrast only.

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