On a clear night a bluish-white star and a reddish star are seen. What does the difference in their colours tell us?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → The bluish-white star has a hotter surface than the reddish star.
The colour of a star depends on the temperature of its surface. The hottest stars look blue or bluish-white, stars like the Sun look yellow, and the coolest stars look red.