Light Curves: Tracking Variable Stars and Exoplanets

A light curve is a graph showing how an object’s brightness changes over time.
Variable stars, like Cepheids, reveal their pulsations through distinct light curves.
Astronomers use light curves to measure stellar properties such as size and temperature.
When an exoplanet passes in front of its star, the light curve dips slightly—a transit.
The depth of the dip tells us the planet’s size, while timing reveals its orbit.
Eclipsing binary stars show repeating patterns as the stars pass in front of each other.
Supernovae create dramatic spikes in light curves that fade over weeks or months.
Missions like Kepler and TESS rely on light curves to find thousands of exoplanets.
Even tiny fluctuations in brightness can uncover new worlds or stellar mysteries.
Light curves are one of astronomy’s simplest yet most powerful tools for discovery.