Redshift & Blueshift: Is There a Consensus?

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SUMMARY

The discussion centers on the concepts of redshift and blueshift in astronomy, specifically regarding the movement of galaxies. It is established that all measurements of cosmological expansion are redshifted, while local motions can result in blueshifted readings. The Milky Way is currently on a collision course with the Andromeda galaxy, along with other nearby galaxies within the Local Group, which are not expanding away from each other. Resources such as NASA's NED and Cornell's astronomy site provide additional information on blue-shifted objects and galaxy interactions.

PREREQUISITES
  • Understanding of redshift and blueshift in astronomy
  • Familiarity with the concept of galaxy clusters
  • Knowledge of the Local Group of galaxies
  • Basic navigation of astronomical databases like NASA's NED
NEXT STEPS
  • Research the implications of redshift measurements in cosmology
  • Explore the dynamics of galaxy collisions, focusing on the Milky Way and Andromeda
  • Investigate the catalog of blue-shifted objects using NASA's NED
  • Learn about the structure and composition of the Local Group of galaxies
USEFUL FOR

Astronomy enthusiasts, astrophysicists, and students studying galaxy dynamics and cosmological expansion will benefit from this discussion.

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Since we have been taken readings of redshift, blueshift for sometime now, is there a consensus on a percentage of each?
 
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You need to be a LOT more specific. If you mean measurements of cosmological expansion, all measurements are redshifted. If you mean the local volume, then they are dependent on local motions and I don't know the mix.

What are you asking?
 
novice at astronomy

In short I guess what I'm trying to ask is , besides the Andromeda galaxy, are there any other large bodies coming our way, or are they all expanding outward from us?
 
I believe there are at least another two galaxies approahing us.
They are fairly local.
You could try NASA site or NED, to ask your question.
 
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http://nedwww.ipac.caltech.edu/cgi-bin/nph-allsky?ra_constraint=Unconstrained&ra_1=&ra_2=&dec_constraint=Unconstrained&dec_1=&dec_2=&glon_constraint=Unconstrained&glon_1=&glon_2=&glat_constraint=Unconstrained&glat_1=&glat_2=&z_constraint=Less+Than&z_value1=0&z_value2=&z_unit=km%2Fs&ot_include=ANY&ex_objtypes1=Clusters&ex_objtypes1=Supernovae&ex_objtypes1=QSO&ex_objtypes2=AbsLineSys&ex_objtypes2=GravLens&ex_objtypes2=Radio&ex_objtypes2=Infrared&ex_objtypes3=EmissnLine&ex_objtypes3=UVExcess&ex_objtypes3=Xray&ex_objtypes3=GammaRay&nmp_op=ANY&out_csys=Equatorial&out_equinox=B1950.0&obj_sort=RA+or+Longitude&zv_breaker=30000.0" lists 2189 blue-shifted objects.
 
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LocktnLoaded said:
In short I guess what I'm trying to ask is , besides the Andromeda galaxy, are there any other large bodies coming our way, or are they all expanding outward from us?

Seems that the Milky Way is already colliding with another galaxy and there are a few more on the way.
http://curious.astro.cornell.edu/question.php?number=386

The Andromeda galaxy collision will just be much more significant.

The Milky Way is part of a "Local Group" of galaxies which are not expanding away from each other (galaxies tend to be found in clusters).
http://www.seds.org/messier/more/local.html
 
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