The star's spectrum is analyzed; certain lines in the spectrum, which have a fixed position, will change their position when the object moves away from us or towards us.
The light from distant galaxies is redshifted. The only reasonable explanation for that is that the galaxies are moving away from us.
By examining its spectrum, and identifying absorption lines in it. Lines are shifted toward shorter wavelength if the object is moving towards us. They're shifted toward longer wavelength if the object is moving away from us.
The object - planet, meteoroid, comet, spaceship - is traveling THROUGH space; the galaxy is moving away WITH space. That is, the space itself is expanding.
The Andromeda Galaxy red shift is -301 km/s Which actually means it is blue shifted and is heading towards us at about 100 to 140 kilometres per second
Light had properties of frequency that related to colour. It is apparently contract in the direction moving toward the observer (higher frequency-short wavelength) and apparently elongated in the direction moving away from observer (lower frequency-high wavelength). What moving toward us is tend to be look more blue than usual (blue shift) and what away from us is redder than usual (red shift).
It would mean that the universe was radially static. That is, no galaxy was moving towards or away from the earth. This could happen if everything in the whole universe were moving in the same direction at the same [linear or rotational] velocity.
A Galaxy's red-shift can be used to determine how fast it is travelling away from you. The opposite is "blue-shift" which is what happens when the Galaxy is travelling towards you.The first astronomers, such as Edwin Hubble, to analyse the light coming from distant galaxies discovered that almost all of them were red-shifted, indicating that they were almost all heading away from us. This was the first indication that the universe was expanding.
No, however, we can determine whether a galaxy is moving towards or away from us, by looking at the shift in its spectrographic analysis. There are "red shifts" and "blue shifts" in spectrographic results. "Blue shifts" indicate that a galaxy is moving towards us, because the wavelength of the light emitted by the galaxy is compressed, causing it to shift to the blue end of the colour spectrum. "Red shifts" indicate that a galaxy is moving away from us, because the wavelength of the light emitted by the galaxy is being stretched towards the red end of the colour spectrum.
Astronomers can determine the rotation of a galaxy by measuring the Doppler shift of the light emitted by stars and gas within the galaxy. The rotation speed can be calculated by observing the difference in wavelengths of light from objects moving towards or away from us. This information allows scientists to create maps of how the galaxy's stars and gas are moving.
We are part of the milky way galaxy, so we are moving with it.
Distant galaxies are moving away from Earth at faster speeds compared to nearby galaxies. This is due to the expansion of the universe, where galaxies farther away experience a greater redshift, indicating faster recession velocities. This relationship is described by Hubble's Law, which states that the recessional velocity of a galaxy is directly proportional to its distance from us.
incorrect. The farther away from earth a galaxy is, the faster it is moving.