Why Do Stars Appear Blue to the Naked Eye but Red in Scientific Images?

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SUMMARY

Stars appear blue to the naked eye due to the limitations of human vision, while scientific images often depict them as red due to redshift phenomena. Redshift cannot be perceived without specialized tools, as local redshifts are too small to detect and cosmological redshifts involve distant objects beyond the reach of unaided observation. The discussion clarifies that the perception of color in stars is influenced by both distance and the observer's capabilities.

PREREQUISITES
  • Understanding of redshift concepts, including local and cosmological redshift.
  • Familiarity with basic astronomy and the electromagnetic spectrum.
  • Knowledge of observational tools used in astrophysics, such as telescopes.
  • Awareness of human visual perception limitations in astronomy.
NEXT STEPS
  • Research the differences between local and cosmological redshift.
  • Learn about the electromagnetic spectrum and its relevance to star observation.
  • Explore the types of telescopes and instruments used to detect redshift.
  • Investigate how human vision perceives color in astronomical contexts.
USEFUL FOR

Astronomy enthusiasts, astrophysicists, and students studying celestial phenomena who seek to understand the visual discrepancies in star observations and the science behind redshift.

elbeasto
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When I look at the stars in the sky with my undressed eye, they are blue. But pictures of stars taken by scientist always show them as red.

Does this mean that the stars in our galaxy are fairly stationary and/or moving closer to earth? Will I find that most red shifts will be seen in stars that are in other galaxies? Or does this mean I need some expensive tool to see the red shift?
 
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elbeasto said:
When I look at the stars in the sky with my undressed eye, they are blue. But pictures of stars taken by scientist always show them as red.
Always? Where did you get that idea?
elbeasto said:
Does this mean that the stars in our galaxy are fairly stationary and/or moving closer to earth? Will I find that most red shifts will be seen in stars that are in other galaxies? Or does this mean I need some expensive tool to see the red shift?
There is local and cosmological redshift - http://en.wikipedia.org/wiki/Redshift"
The short answer is that you can't perceive redshift with the unaided eye. Local reshifts are too small to differentiate and the objects affected by cosmological redshifts are too far to see.
 
Last edited by a moderator:
Borg said:
Always? Where did you get that idea?

You are right. They are not 'always' red. I was making a statement more casual and generic than I should.

Borg said:
... you can't perceive redshift with the unaided eye. Local reshifts are too small to differentiate and the objects affected by cosmological redshifts are too far to see.
Cool thanks.
 

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