In addition to the proper motion, we also need the to find the transverse velocity of a star across our line of sight.
A) temperature
B) parallax
C) composition
D) mass
E) color

Question

Quizplus · Accepted Answer

To find the transverse velocity of a star across our line of sight, we need to know the star's parallax. The parallax allows us to determine the distance to the star, which, combined with the proper motion, can be used to calculate the transverse velocity.

In Addition to the Proper Motion, We Also Need the to Find