Which of these colors of light passes most easily through interstellar clouds? a Green light b Red light c Blue light d Violet light

Barnard's Star is the 2nd closest star to Sol (~ 6 light years). It is moving toward the Earth with a speed of 110 km/s. Calculate the blue shift of light from Barnard's star, defined by AX/X. OA: OB: OC: OD: OE: -3.668x10-4 -4.586x10-4 -5.732x10-4 -7.165x10-4 OF: OG: -8.956x10-4 -1.120x10-3 -1.399x10-3 OH: -1.749x10-3

The three most prominent spectral lines of hydrogen are H-α at 656 nm, H-β at 486 nm, and H-γ 434 nm. If we observe an object with H-α at a wavelength of 700 nm, what wavelength will we observe H-β and H-γ? Is the object moving toward or away from us, and how do you know? Suppose we observe another object with H-α at 585 nm. Is this object moving toward or away from us? Is it moving slower or faster than the first object?

An astronomer observes several stars with different colors. Rank them in order from highest temperature to lowest temperature.  1 is the highest temperature, 2 is the next highest, 3. Third highest, 4. lowest temperature orange-red star bluish-white star yellowish-white star red star