Q. Consider the following statements regarding stellar evolution:
1.When a main-sequence star significantly more massive than the Sun exhausts its hydrogen, it contracts and turns into a White Dwarf immediately.
2.Our Sun is destined to expand into a Red Giant once its core hydrogen is depleted and helium fusion ignites.
3.As a star becomes a Red Giant, the core expands and cools, while the outer layers contract inward to increase pressure.
Which of the statements given above is/are correct?
Answer: A
Notes:
Explanation: (Statements 1 and 3 are incorrect/swapped concepts)
- Statement 1 is incorrect: Massive stars become Supergiants and eventually go Supernova; only average stars become White Dwarfs.
- Statement 2 is correct: This is the predicted fate of our Sun in about 5 billion years.
- Statement 3 is incorrect: In a Red Giant, the core contracts (increasing heat/pressure) and the outer layers expand (making the star larger).
