Question

evolution occurs too slowly to be detected, scientists often study numerous stars in different phases of their lives to infer what happens to them over time.

One observation that scientists have made is that the initial mass of a star determines its evolution. How does the evolution of a low-mass star differ from that of a more massive star?
A.
Stars with masses less than 1.6 × 1029 kg become brown dwarfs because they are unable to reach high enough temperatures for hydrogen fusion to take place.
B.
Extremely massive stars are able to produce supernovas, or stellar explosions, when they cease to undergo nuclear fusion or when they undergo a sudden gravitational collapse.
C.
Low-mass stars develop more slowly than more massive stars; their lifetimes can last trillions of years as opposed to only a few million years.
D.
all of the above

Answer 1

D.

All three statements are correct:
- A: ~1.6×10^29 kg ≈ 0.08 solar masses is about the minimum mass for sustained hydrogen fusion; below that, objects are brown dwarfs.
- B: Very massive stars can undergo core collapse (or, in other cases, thermonuclear events) that produce supernovae when fusion can no longer support the core.
- C: Low-mass stars burn fuel much more slowly and can live for billions to trillions of years, whereas massive stars have much shorter (millions–tens of millions year) lifetimes.