What causes stars to twinkle?
A) It is intrinsic to the starstheir brightness varies as they expand and contract.
B) variations in the absorption of the atmosphere
C) variable absorption by interstellar gas along the line of sight to the star
D) bending of light rays by turbulent layers in the atmosphere
E) the inability of the human eye to see faint objects
Question 2
The red hydrogen alpha line carries more energy per photon than the blue-green hydrogen beta line does.
Indicate whether the statement is true or false
Much of the dark space between stars, as seen in the sky of the image above, is due to the human eye
Solar Energy Input Varies with Latitude
Hertzsprung-Russell diagram for a set of stars that includes the Sun
Stars vary widely in size.
Binary Stars
Saturation and Brightness