Light curve

Although the categorisation of variable star types is increasingly done from their spectral properties, the amplitudes, periods, and regularity of their brightness changes are still important factors.

Some types such as Cepheids have extremely regular light curves with exactly the same period, amplitude, and shape in each cycle.

[1] The shapes of variable star light curves give valuable information about the underlying physical processes producing the brightness changes.

[5] In planetary science, a light curve can be used to derive the rotation period of a minor planet, moon, or comet nucleus.

The time separation of peaks in the light curve gives an estimate of the rotational period of the object.

The Asteroid Lightcurve Database (LCDB) of the Collaborative Asteroid Lightcurve Link (CALL) uses a numeric code to assess the quality of a period solution for minor planet light curves (it does not necessarily assess the actual underlying data).

Light curve inversion is a mathematical technique used to model the surfaces of rotating objects from their brightness variations.

This is caused by the small relativistic effect as larger gravitational lenses, but allows the detection and analysis of otherwise-invisible stellar and planetary mass objects.