The supergiant stars Betelgeuse and Rigel in the Orion region of the sky appear particularly bright because
A) they are in a region of low interstellar medium density and,therefore,are not heavily obscured compared to equivalent stars elsewhere.
B) they are close in our spiral arm.
C) they are very luminous.
D) their high surface temperatures make them easy to see,even though they are intrinsically faint and far away,because most of their light is concentrated in the visible range.

Question

Quizplus · Accepted Answer

Betelgeuse and Rigel are supergiant stars, which means they are highly luminous and have a large radius. This makes them appear particularly bright in the sky, even though they are relatively far away.

The Supergiant Stars Betelgeuse and Rigel in the Orion Region