Author Question: A star is on the horizontal branch of the H-R diagram. Which statement is true? A) It is burning ... (Read 42 times)

ec501234 · **on:** Jul 27, 2018

A star is on the horizontal branch of the H-R diagram. Which statement is true?

A) It is burning only helium.
B) The star is contracting.
C) The star is about to return to the main sequence.
D) It is about to experience the helium flash.
E) It is burning both hydrogen and helium.

Question 2

Why do Uranus and Neptune appear blue?

A) Methane gas absorbs all colors except blue.
B) Gas molecules in their atmosphere preferentially scatter blue light.
C) Small dust grains preferentially scatter blue light.
D) Methane snowflakes absorb all colors except blue, which they reflect.