Question

a star is observed to have a temperature of 3000 k and a luminosity of 10^5. what is the color of the star? what group does the star belong to?

Explanation:

Step1: Recall star - color and temperature relation

Stars with lower temperatures are red. A star with a temperature of 3000 K is relatively cool.

Step2: Identify star group from HR - diagram

Looking at the Hertzsprung - Russell (HR) diagram, a star with a temperature of 3000 K and luminosity of $10^{5}$ lies in the supergiant region.

Answer:

Color: Red
Group: Supergiants