Light curves are graphical representations of the brightness of an astronomical object over time. They are commonly used in the field of astronomy to study the variability of stars, galaxies, and other celestial objects. By measuring the changes in brightness over time, astronomers can gain insights into the physical properties and behavior of these objects. Light curves can provide information on the rotation rate, presence of companions, and physical conditions of the object being studied. They are a powerful tool for astronomers to understand the dynamic nature of the universe.