Suppose one could examine a star and determine its absolute magnitude M without any intervening gas and dust. Compared to its absolute magnitude measured with gas and dust between Earth and the star, this "clean" measurement of M would be
A) a larger number.
B) a smaller number.
C) the same number.
D) either larger or smaller depending on the star's speed (toward or away).

Question

Quizplus · Accepted Answer

Absolute magnitude is a measure of the intrinsic brightness of a celestial object, which does not change regardless of the presence of gas and dust or the observer's location. It is defined as the apparent magnitude the object would have if it were located at a standard distance of 10 parsecs from the observer, without any intervening material. Therefore, the presence of gas and dust does not affect the absolute magnitude of a star.

Suppose One Could Examine a Star and Determine Its Absolute