Of the methods listed below, which is the best for measuring the distance to the Andromeda galaxy, a member of the Local Group?
A) the Cepheid variable period-luminosity relationship
B) Hubble's law
C) trigonometric parallax

Question

Quizplus · Accepted Answer

The Cepheid variable period-luminosity relationship is the best method for measuring the distance to the Andromeda galaxy because Cepheid variables are bright enough to be observed at such distances and their period-luminosity relationship allows for accurate distance calculations. Trigonometric parallax is only effective for nearby stars, and Hubble's law is more suitable for distant galaxies beyond the Local Group.

Of the Methods Listed Below, Which Is the Best for Measuring