12 Two stars are identified on the Hertzsprung-Russell diagram below.
Hertzsprung-Russell Diagram
Temperature
10° 40,000 20,000 10,000 7,500 5,500 4,500 3,000
10
1
10
10
104
O
Spectral Class
Based on this diagram, how do the characteristics of Star 1 and Star 2 compare?
A Star 1 is cooler and less bright than Star 2.
B Star 1 is hotter and brighter than Star 2.
Star 1 is cooler and brighter than Star 2.
D Star 1 is hotter and less bright than Star 2.