What Causes Multi-Colored Stars to Twinkle in the Night Sky?

  • Context: High School 
  • Thread starter Thread starter NerfMonkey
  • Start date Start date
  • Tags Tags
    Stars
Click For Summary

Discussion Overview

The discussion centers on the phenomenon of multi-colored stars twinkling in the night sky, particularly focusing on the causes of this effect as observed by participants. The scope includes observational astronomy and atmospheric effects on starlight.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant observed a star appearing to flash in multiple colors (red, green, blue) and speculated that atmospheric conditions, possibly lingering rain, could be causing this effect through diffraction.
  • Another participant identified the phenomenon as scintillation, attributing it to perturbations in the air caused by temperature differentials, which can affect the stability of the atmosphere.
  • A third participant noted that the temperature difference between day and night could contribute to the observed scintillation, particularly if the telescope had not cooled down sufficiently.
  • Another participant explained that the twinkling colors observed when stars are low on the horizon are due to atmospheric refraction, which separates the colors similar to a prism.

Areas of Agreement / Disagreement

Participants generally agree that scintillation and atmospheric effects are responsible for the twinkling of stars, but there are differing views on the specific mechanisms involved, particularly regarding diffraction and refraction. The discussion remains unresolved regarding the exact contributions of these factors.

Contextual Notes

Participants have not fully explored the assumptions regarding atmospheric conditions or the specific definitions of diffraction and refraction in this context.

NerfMonkey
Messages
36
Reaction score
1
I was out observing about an hour ago (finally found M51 for the first time :biggrin:) when I noticed what I assumed was a star to the northeast just a few degrees above the horizon. I looked at it and immediately noticed it appeared to be flashing, but not like an airplane. I stared at it more closely and saw that it looked red, green and blue, and that it was changing colors. Looking at it through my finder scope and then my telescope at low magnification it looked like all three colors at once, but looking at it at much higher (250x) magnification it looked like all three colors at once with a halo around it that was changing brightness every half second or so and sometimes disappearing altogether. There was another star doing this too, but it was higher up in the sky.

The only theory I can come up with for this is that we got rain yesterday, and some of it could still be lingering in the atmosphere. The starlight could be getting "split" (I'm not sure of the correct term, diffracted?) into rainbowy colors. This would make sense for the low star near the horizon because the light would be traveling through the atmosphere farther to reach me than if it was closer to the zenith, but it doesn't explain the other star that was much higher up.

Any ideas or explanations for this? Thanks in advance.
 
Astronomy news on Phys.org
The term you're looking for is http://en.wikipedia.org/wiki/Scintillation_%28astronomy%29" . It is caused by perturbations in the air from warm/cold differentials in the column of air through which you are looking. In stable air of a uniform temperature, this effect is greatly reduced.
 
Last edited by a moderator:
Last night was much colder than it had been during the day and I didn't allow as much time as I usually do for the scope to cool off so that would make sense. Thanks for the reply.
 
Scintillation makes stars twinkle. What makes them twinkle in color when they are low is the refraction of the atmosphere separating the colors like a prism.
 

Similar threads

  • · Replies 15 ·
Replies
15
Views
4K
  • · Replies 49 ·
2
Replies
49
Views
12K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 0 ·
Replies
0
Views
3K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 5 ·
Replies
5
Views
5K
  • · Replies 12 ·
Replies
12
Views
5K
  • · Replies 25 ·
Replies
25
Views
5K
  • · Replies 16 ·
Replies
16
Views
8K
  • · Replies 24 ·
Replies
24
Views
14K