Two stars, Star A and star B, have equal luminosities. Star A is closer and has a slightly higher surface temperature while Star B is farther away from Earth and has a slightly lower surface temperature.

Question

Which star will have the higher apparent magnitude?

(1 point)
Responses

Star A will have a higher apparent magnitude because it has a higher surface temperature.
Star A will have a higher apparent magnitude because it has a higher surface temperature.

Star A will have a higher apparent magnitude because it is at a lesser distance.
Star A will have a higher apparent magnitude because it is at a lesser distance.

Star B will have a higher apparent magnitude because it is at a greater distance.
Star B will have a higher apparent magnitude because it is at a greater distance.

Star B will have a higher apparent magnitude because it has a lower surface temperature.

Answer 1

Apparent magnitude is a measure of how bright a star appears from Earth, and it depends primarily on its luminosity and its distance from the observer. Since both stars have equal luminosities, the star that is closer will appear brighter than the star that is farther away.

Star A, being closer to Earth, will have a higher apparent brightness than Star B, despite Star A having a slightly higher surface temperature. The temperature affects the color and spectrum of the star but does not change the apparent magnitude directly if the luminosities are equal.

Therefore, since Star A is closer, it will have a lower (brighter) apparent magnitude compared to Star B.

The correct conclusion is that Star B will have a higher apparent magnitude because it is at a greater distance.

Thus, the correct response is:

Star B will have a higher apparent magnitude because it is at a greater distance.