Question

Select all that apply.

The spectrum of Star X is compared to a reference hydrogen spectrum. What can be concluded about Star X?
https://clackamasweb.owschools.com/media/g_ipc_2014/11/doppler_shift_star_x.jpg


Star X is showing radial motion.
Star X is moving toward the Earth.
Star X is moving away from the Earth.
Star X may be moving, but its motion is not radial.

Answer 1

There is no shift right?

Answer 2

a shift in wavelength occurs: when there is a relative radial motion

Answer 3

so it is the two last ones?

Answer 4

@UnkleRhaukus

Answer 5

if it were moving away, (as in option c), there would be a red shift. but no shift is observed

Answer 6

so just the last one?

Answer 7

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If the star X is moving, it must be traverse motion (relative to the observer)

Answer 8

thnxx:)