In order to measure the parallax angle of a star,it is necessary to know the direction to the star on two different days of the year and
A) nothing else.
B) the star's luminosity (total energy output per second).
C) the star's surface temperature.
D) the star's spectrum.

Question

Quizplus · Accepted Answer

To measure the parallax angle of a star, you only need to know the direction to the star from Earth at two different points in its orbit around the Sun. This allows you to measure the apparent shift in the star's position against the background of more distant stars, which is used to calculate its distance from Earth. The star's luminosity, surface temperature, and spectrum are not necessary for measuring parallax.

In Order to Measure the Parallax Angle of a Star,it