Question

A Hertzsprung-Russel diagram is shown.

A graph with temperature in Kelvin on the x-axis from 40000 to 2500 and luminosity in lumens of the sun on the y-axis. There are labeled areas on the graph with plotted points. The area labeled Supergiants has 3 points, (4900, 14000), (3000, 10000) and (2800, 100000). The area of white dwarfs lies between (35000, .1) and (7000, .0001). The area of red giants run from (6000, 10) to (2600, 100). There is a curve of points, labeled main sequence, between (25000, 10000) all the way down to (2500, .0001).
Which stars are best characterized as having high temperatures and low luminosities?

red giants
white dwarfs
supergiants
main sequence

Answer 1

White dwarfs.

They occupy the lower-left of the H–R diagram (high temperature, low luminosity), unlike supergiants/red giants (high luminosity) or most main-sequence stars (luminosity varies with temperature).