Some objects in space just don't have what it takes to be a star (just like many hopefuls in Hollywood don't.) Which of the following is a "failed star", an object with too little mass to qualify as a star?
A) a brown dwarf
B) an M type dwarf
C) an O-type star
D) the Sun
E) any star with high proper motion

Question

Quizplus · Accepted Answer

Brown dwarfs are sometimes referred to as "failed stars" because they have insufficient mass to sustain nuclear fusion in their cores and thus cannot become true stars. M type dwarfs and O-type stars are still considered stars, albeit with different characteristics and mass ranges. The Sun is a main sequence star, also known as a G-type dwarf. Proper motion is a measure of a star's apparent motion across the sky and is not directly related to whether it is a failed star or a true star.

Some Objects in Space Just Don't Have What It Takes