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Gliese 581c/d and their Red Sun?

  1. Jan 8, 2008 #1
    I am doing some research for a graphic novel I am building with a group that will take place on Gliese 581c/Gliese 581d and am trying to get as accurate information as possible about what the sky, light and plant life would look like in either of these environments. Could this be an accurate representation?
    "[URL [Broken]
    Red and Purple Atmosphere?[/URL]
    Last edited by a moderator: May 3, 2017
  2. jcsd
  3. Jan 8, 2008 #2


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    That looks like Earth through a purple filter!
    The sky would look redder to us - of course if something eveolved on the planet then the sky would look normal, just as creatures from a bluer sun would think our sky was too red!
    would probably need larger leaves to capture enough energy from the weaker red photons and different photo chemistry of course.
    Being much nearer to a larger cooler sun would have different weather patterns and seasons.
  4. Jan 8, 2008 #3
    Thanks MGB. Implying that the photo chemistry would be different begins to hint at the idea that plant life may be completely different from green? Maybe even dark purple or charcoal black to absorb light more effectively? A studio member of mine suggested that the greater gravity of the Gliese "Super Earth" might only support short stocky life which seems to make some logical sense, but also puts a damper on some of my creative concept development (I think the "Super Earth" gravity is estimated as 1.5x greater than earth)
  5. Jan 8, 2008 #4
    The sky would still be blue, I believe, since we get our blue sky from Rayleigh scattering of sunlight.

    Also, the star in the image that was linked to is far too red; it would actually be a light orange-ish color. You can see at:


    Gliese 581 is about 3,500 K.
  6. Jan 8, 2008 #5


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    That's a nice chart! I can use it to tell the temperature of the electric heating coils on the stove.

    So maybe the Gliese sun would look like an apricot? It would look BIG I guess, being relatively close (even tho smaller in absolute size)

    Actually isn't the tungsten filament of a 100 watt lightbulb something like 3500 K?
    The cast of light might not look all that unfamiliar.
    The atmosphere might be very deep and optically thick. If it wasn't too cloudy I expect you are right that it would be blue.
    Last edited: Jan 8, 2008
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