Using red shift can we see some stars moving away from us and some moving with us, or towards us?

Question

What i mean is, when we use red shift to backup the theory that the universe is expanding, therefore stars moving away from us, does this red shift also show some stars that are moving a similar speed to us ie not much or no red shift, or are all stars moving away from one another. Are some stars behind us catching up to us? and some in front moving further away? Or are we catching up to ones in front, or speeding away from ones behind? Does red shift show this information?

Answer 1

Yes, there are stars moving toward us. But the expansion of the universe is bigger than just stars. It is whole galaxies. And even then, it is distant galaxies. Some nearby galaxies are moving toward us. But distant galaxies are ALL moving away from us. The farther away a galaxy is, the faster it moves away from us. But it isn't only us. From the point of view of a distant galaxy, we are moving away from it. The whole universe is expanding, with every galaxy getting farther from every other galaxy, with the exception of some galaxies near each other that may be staying close together as a pair.

Answer 2

It's a complicated question. John's answer comes close.

The color red on a wavelength spectrum is not a single length. As with a rainbow, the colors occupy more than a single line and blend with the next color. In this case, red is measured as between 650 and 700 nanometers. Thus, according to the specific wavelength, we are able to obtain velocity of the object (measured in kilometers per second) and measure how fast or slow the object is moving towards or away from us.

The Big Bang generally exploded outwards in all directions. However, once things started to cool, things were not spread out evenly. So you have things like angular momentum and gravitational effects causing areas to spin. Chaos is introduced. The result being that some things collide into other things. Not just debris but stars and entire galaxies colliding into one another. Pictures of such collisions have been and can be viewed with the Hubble telescope.

The question becomes complicated because science is still young when it comes to Doppler red shift. We are finding now that spiral galaxies have a greater red shift than ellipticals and this is not due to their velocity but perhaps their energy levels. A 1987 January Sky and Telescope article indicated a need to quantize the Doppler effect. Red shift may not be Doppler related but instead may be a property of the observed galaxy. In 1947 Edwin Hubble warned that red shift may be related to other causes other than distance recession. Current data by the Pioneer 10 Doppler proves that photons (light waves particles) are able to lose energy by some unknown effect which can lead to a decrease in frequency without a similar decrease in speed. This would create a red shift unrelated to distance recession. Stay tuned.

Answer 3

Well you have two different things going on.

One is the relative motion of stars and galaxies, relative to ourselves. If the object is moving closer to us the shift is blue, if moving away, it's red. Both depend on the relative velocity. You see both kinds of motion. These are unrelated to the expansion of the universe.

Superimposed on that picture, there is another red shift (always red) related to the expansion of the universe. All objects at any significant distance display this shift, and the farther away they are, the greater the shift. They greater the shift, the faster they can be said to be moving. This is true, regardless of where you are observing from (our galaxy or another). That last point is what confirms the expansion of the universe and the approximate date of the big bang. A simple analogy is dots painted on a balloon. As you inflate the balloon the dots move apart, regardless of which dot you choose for your point of reference.

Answer 4

The Andromeda Galaxy (which you can see naked eye, somewhat between the Great Square of Pegasus and the big W or M (Cassaeiopea) near the north star is moving towards our galaxy. Therefore, we see a blue shift, not a red shift. (Look up the Doppler Effect to see why it shifts in the direction of red or blue).

The way I understand it, this means that Andromeda Galaxy, for instance, is moving towards us overall. But that doesn't mean that the Universe isn't expanding. It's as though someone running on top of a semi truck trailer is running towards the back of the truck to jump off, even though the truck is driving down the highway. (The Matrix)

Answer 5

The expansion of the universe is noticeable on very large scales. Even within our own Local Group of galaxies, gravity is still stronger than the expansion. We use redshift of galaxy light to study the effect of expansion on galaxies located billions of light-years away.

Redshift (and blueshift) of individual stars is used within our own Galaxy to study the movement of stars around us. This allows us to determine, for example, the movement of stars around the centre of the Galaxy and, therefore, estimate the amount of mass between these stars and the centre of the Galaxy. We find that stars closer to the centre are "passing" us, while we are passing stars that are further away from the centre than we are.

Answer 6

Red shift means an object in moving AWAY from us
Blue shift means an object is moving TOWARD us

To put it simply!

Answer 7

Moving closer to us is what's known as the blue shift, the other end of the light spectrum.

http://en.wikipedia.org/wiki/Blue_shift

Answer 8

red shift tells us all of that. i don't remember which direction is which color (i think red means it's moving toward us) but objects moving away from us are also have a red shift, just in the other direction; their shift is toward the long wavelengths of visible light on the electromagnetic spectrum

Answer 9

What?!