Which of these distance-measuring techniques only works for objects out to 1500 light-years?
A) Parallax
B) Supernovae Ia
C) Tully-Fisher
D) Cepheid variables

Question

Quizplus · Accepted Answer

Parallax is only useful for objects within 1500 light-years because the farther away an object is, the smaller its parallax angle becomes, making it more difficult to accurately measure its distance. Supernovae Ia, Tully-Fisher, and Cepheid variables can be used to measure distances much farther than 1500 light-years.

Which of These Distance-Measuring Techniques Only Works for Objects Out