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Question about suns and the sky

  1. Jul 22, 2009 #1
    Ok, this is kind of a stupid question, but I was curious... If I lived on a planet that had an atmosphere, but a red sun, what color would the sky be? If I lived on a planet with two suns, one red, and one blue, what color would the sky be? I know some light is absorbed into the atmosphere and that is why it looks blue, but if there is more red light than blue would it look red, or just darker?
    Sorry it's kinda dumb, but really, I'm awful curious and can't find the answer.. :)

    Thanks! :)
  2. jcsd
  3. Jul 22, 2009 #2


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    Staff: Mentor

    No, it would look blue, just darker. The sky scatters blue light.
  4. Jul 23, 2009 #3


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    Science Advisor
    Gold Member

    Depends on the atmospheric composition. In an earth atmosphere, a red sun could cause the sky to be very blue - as russ noted. In a double star [blue and red component] system, the effects would be more complicated. A faintly blue sky would be my best guess, depending on the distance to the component stars. It could be a quite spectacular - and lethal combination.
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