Which of the following characteristics of a single star (one that moves through space alone) is it difficult to measure directly?
A) its apparent brightness
B) its temperature
C) its chemical composition
D) its mass
E) you can't fool me, all of these are quite easy to measure directly

Question

Quizplus · Accepted Answer

Measuring the mass of a single star is difficult because we cannot directly observe the gravitational attraction between two stars, which is one of the most common methods for measuring the mass of celestial objects. Instead, we have to rely on indirect methods, such as observing the star's orbit around a companion or studying its brightness variations caused by pulsations.

Which of the Following Characteristics of a Single Star (One