Cepheid Variables

Cepheid variables are a type of star that pulsate in a regular cycle, causing them to brighten and dim over time. This pulsation is linked to their intrinsic brightness, making them reliable indicators of distance in the universe. By measuring how long it takes for a Cepheid variable to complete one cycle, astronomers can determine its true brightness. Comparing this to how bright the star appears from Earth helps calculate how far away it is. Cepheid variables thus play a crucial role in measuring distances in space and understanding the scale of the universe.