Distance Modulus

The distance modulus is a way astronomers measure how far away a star or galaxy is. It compares the star's true brightness (how bright it really is) with how bright it appears from Earth. Because distant objects appear dimmer, the difference between these two brightness levels helps determine their distance. If an object appears faint, it’s likely farther away; if bright, closer. The distance modulus is calculated using a simple formula, and it links the observable brightness to the distance, making it a fundamental tool in understanding our universe’s scale.