Question

characteristics of stars
◆ understanding main ideas
use the following h - r diagram to answer questions 1 - 3.
write your answers in the spaces provided.

1. which star has the greatest brightness?
2. which has the lowest brightness?
3. stars c and d have the same brightness.

what would you need to know to deter - mine their relative magnitudes?

Explanation:

Step1: Analyze the H - R diagram

In an H - R diagram, the vertical axis represents brightness. The higher a star is on the vertical axis, the greater its brightness.

Step2: Identify the star with the greatest brightness

Star A is the highest on the brightness axis among the given stars, so it has the greatest brightness.

Step3: Identify the star with the lowest brightness

Star F is the lowest on the brightness axis among the given stars, so it has the lowest brightness.

Step4: Determine what's needed to compare C and D

Since C and D have the same brightness, to determine their relative magnitudes, we need to know their distances from Earth as brightness observed from Earth depends on both the actual luminosity of the star and its distance.

Answer:

1. A
2. F
3. Their distances from Earth