Credit: NASA, R. Crawford (STScI)
A star can have dozens of spots scattered across its surface at any one time, causing irregular brightness fluctuations that make it difficult to tease out periodic signals of dimming due to the star’s rotation. This graph of data from the butterpy program shows how the observed brightness of a simulated star would vary over a single rotation period. NASA’s Roman Space Telescope will be able to measure the light curves, and therefore rotation rates, of hundreds of thousands of stars, bringing new insights into stellar populations in our galaxy.