Answer: Trigonometric or Stellar Parallax
Step-by-step explanation:
Whenever a star is too far away to measure its parallax, astronomers do match its color and spectrum to one of the standard candles and determine its intrinsic brightness.
Comparing this to its apparent brightness, they can get a good measure of its distance by applying the 1/r^2 rule.
Astronomers estimate the distance of nearby objects in space by using a method called stellar parallax, or trigonometric parallax. They measure a star's apparent movement against the background of more distant stars as Earth revolves around the sun.