Astronomers find that light emitted by a particular element at one edge of the sun...

Question

...has a slightly higher frequency than light from that element at the opposite edge.

What do these measurements tell us about the suns motion?

thanks in advance!

Answer 1

It should tell us that the Sun is spinning. The light from the side that is receding away from us would be expanded in frequency due to the Doppler Effect, and the light from the side that is coming towards us would be compressed and increased in frequency.

Answer 2

To start with it is a known fact that the atoms of the same element & isotope should have same emission spectra, provided that the energy source is constant & other physical conditions remain the same.

Therefore if an atom of same element & isotope at one edge has a slightly higher frequency we can safely deduce that it is the Doppler effect coming into play.

Since one edge is rotating towards us, the spectrum from that edge is slightly blue shifted.i.e.it is pushed towards the blue end

of the spectrum. Similarly the spectrum from the receding edge is red shifted.

Thus by studying the two spectra one can deduce the direction of rotation of the sun about its own axis.

Answer 3

that the sun rotates, and that the side with the high frequency is headed toward us.

Answer 4

It tells us that the Sun is about to explode, and we will all instantly die.