Redshift data on stars the same distance from earth

In summary, the conversation discusses the need for hard research data on the absence of detectable redshift differences in stars at the same distance but in different directions, and its relation to the expansion of the universe. It is suggested to search for data in the SIMBAD database and to consult with experts for more specific advice.
  • #1
Jim Hasty
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Can anyone in the cosmology community direct me to hard research data that specifically demonstrates: there is no detectable redshift difference in stars that are the same distance from the Earth but in all different directions. This is of course related to 'does the universe have a preferred direction of expansion', the literature of which I find on google does not provide data, just brief conclusions. Thanks.
 
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  • #2
Individual stars tend to be visible within our galaxy but there is no expansion of such bound objects. Nearby galaxies have the majority of their red- or blue-shift determined by local motions. It's only when you get to more distant galaxies that cosmological redshift starts to dominate, and by then you cannot make out individual stars. Again their motion would be principally that within the galaxy, what you need to do is measure the average for the whole galaxy.

For hard data on galactic redshifts, I would suggest you start with the SIMBAD database but there are others. Once you know what details you want, you can get more specific advice on search criteria.
 
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  • #4
GeorgeDishman said:
Individual stars tend to be visible within our galaxy but there is no expansion of such bound objects. Nearby galaxies have the majority of their red- or blue-shift determined by local motions. It's only when you get to more distant galaxies that cosmological redshift starts to dominate, and by then you cannot make out individual stars. Again their motion would be principally that within the galaxy, what you need to do is measure the average for the whole galaxy.

For hard data on galactic redshifts, I would suggest you start with the SIMBAD database but there are others. Once you know what details you want, you can get more specific advice on search criteria.
Thank you so much, George. This is incredible and helpful.
 

FAQ: Redshift data on stars the same distance from earth

What is redshift data on stars?

Redshift data on stars refers to the measurement of the change in wavelength of light emitted by a star, due to its movement away from the observer. This shift towards the red end of the electromagnetic spectrum is caused by the Doppler effect and can provide information about the star's speed and distance from Earth.

How is redshift data collected?

Redshift data is collected using spectroscopy, a technique that breaks down the light from a star into its component wavelengths. The resulting spectrum can then be compared to a known spectrum to determine the amount of redshift and gather information about the star's motion.

Why is redshift data important in studying stars?

Redshift data is important in studying stars because it allows us to measure their distance and speed, which provides information about their age, composition, and evolution. It also helps us understand the expansion of the universe and the large-scale structure of galaxies.

Are stars with the same redshift data always at the same distance from Earth?

No, stars with the same redshift data are not always at the same distance from Earth. While redshift can indicate a star's distance, it can also be affected by other factors such as its age, composition, and velocity. Therefore, two stars with the same redshift could be at different distances from Earth.

Can redshift data be used to determine the age of a star?

Yes, redshift data can provide valuable information about the age of a star. By measuring the amount of redshift and comparing it to the known expansion rate of the universe, scientists can estimate the star's age. However, this method is not always accurate and must be combined with other data to get a more precise estimate.

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