Question

drag the gray arrow so that it is pointing midway between horizontal and vertical, heading downward and toward the right. extend it as far as it will go. what do you notice about the speed of the star as compared to the speed of the star relative to earth?

Answer 1

The speed of the star as compared to the speed of the star relative to earth is the frequency of light emitted by the source.

A star moving away from the observer (say on Earth) will have its emitted light red-shifted (move to lower frequency), i.e., the spectrum moving to left if we consider the intensity of light is plotted as a function of frequency with the frequency increasing from left to right.

A star moving towards the observer (say on Earth) will have its emitted light blue-shifted (move to higher frequency), i.e., the spectrum moving to the right if we consider the intensity of light is plotted as a function of frequency with the frequency increasing from left to right.

A star moving perpendicular to the observer (say on Earth) will have its emitted light will no change with respect to the spectrum of the stationary star.

These are due to the Doppler effect, the equation of frequency detected by the observer as

$f_o = f_s\sqrt{\frac{1-\beta }{1+\beta } }$ where $\beta = \frac{v}{c}$, v the relative velocity of the moving source (the star here), f^s is the frequency of light emitted by the source.

Hence the answer is the speed of the star as compared to the speed of the star relative to earth is the frequency of light emitted by the source.

To learn more about frequency click here brainly.com/question/26177128

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