stars movement?

Question

if stars are so far away, how do we know that these distant stars are moving at all?

Answer 1

The Doppler effect. Imagine the sound of a car or train approaching you and then passing you. The sound as it moves away from you is much different. Light behaves in the same manner. Stars approaching us would appear more blue-shitted while stars moving away would appear more red-shifted. Almost all stars appear red shifted and the farther away they are, the more red-shifted they are (that is, the farther away they are, the faster they are racing away from us.) This was discovered by Edwin Hubbel in 1929.

Answer 2

Up to this point, all the answers you've gotten are wrong. Measuring the red shift of stars does NOT allow us to measure their distances because the velocity of stars is much to low. The main method for finding the distance to stars is done with techniques based on the principle of parallax. You can demonstrate parallax for yourself. Just pick out some object, like a smudge on your wall. Look at it with one eye covered, then with the other covered. You'll notice the smudge appears to move back and forth. That's parallax in action, and caused by the distance between your eyes. This website gives a good summary of stellar parallax, with illustrations ==>http://hyperphysics.phy-astr.gsu.edu/hbase/astro/para.html#c1

Answer 3

Doppler shift. Most stars have a red hue to them because they are moving away from us. Astronomer can measure the amount of red so to speak and tell that the stars are moving away from a fixed point.



Peace

Answer 4

We use the light that they admit and collect a spectra we know how the spectra should look of a stationary object so depending on how much its shifted we know how fast its moving we can also tell what the star is made of

Answer 5

Hi. By comparing their motion against far more distant objects like quasars. We can use red shift to measure radial motion. Non-radial motion is measured against the more distant objects. Look up Barnard's Star.

Answer 6

Google red shift.

Answer 7

If they weren't moving (rotating and stuff) they would cease to exist because they would not have a gravitational field to keep their mass.