Exam-style question
Try this first
Which spectral class is typically associated with the coolest main‑sequence stars?.
- A.O
- B.K
- C.M
- D.A
Model answer
What a good answer should say
- M
Explanation
Why this works
Define both: M‑type stars are the coolest, with temperatures below 3 500 K, while O, K and A stars are progressively hotter. Identify key difference: M stars have the lowest temperatures and show molecular absorption bands.
Explain when each applies: M stars represent the coolest main‑sequence stars; O, K and A represent hotter classes. Conclude: The coolest class is M.
Common mistake
No common mistake is linked to this question yet.