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

AI Thread Summary
Stars appear blue to the naked eye due to atmospheric scattering, while scientific images often depict them as red due to redshift effects. Redshift cannot be perceived without specialized equipment, as local redshifts are too small to detect and cosmological redshifts involve distant objects. The misconception that stars are always red in scientific images is clarified, emphasizing that this is not universally true. Understanding redshift requires knowledge of local and cosmological contexts. The discussion highlights the limitations of human perception in astronomy.
elbeasto
Messages
33
Reaction score
0
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?
 
Physics news on Phys.org
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.
 
Assume that this is a case where by sheer coincidence, two sources of coherent single-frequency EM wave pulses with equal duration are both fired in opposing directions, with both carrying the same frequency and amplitude and orientation. These two waves meet head-on while moving in opposing directions, and their phases are precisely offset by 180 degrees so that each trough of one wave meets with the crest of the other. This should be true for both the electric and magnetic components of...
Back
Top