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Thread: Up to 22% Dips Detected in Starlight 1,500 LY Away

  1. #781
    Join Date
    Oct 2017
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    6
    Quote Originally Posted by Mudskipper View Post
    they can usually tell from the red-shift and blue-shift, of the sides of the star, if it is rotating, I think...not sure.
    Starlight is a point source. Suppose you were looking down at Ecuador. You could not tell from Doppler if the earth rotates from Chicago towards Quito, Quito to Chicago, the correct way (prograde), retrograde, or anything in between. Looking down at the pole you would not see a Doppler shift. Looking down at a point near the arctic circle you would see some Doppler but not much.

  2. #782
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    Oct 2001
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    JPL News release:
    Wavelength dependent dimming points to micrometer sized dust particles as responsible for the long term dimming. A comet swarm remains the most likely cause of the larger, short-term dimming. These same comets could be a plausible source of the dust for the long-term dimming. More study (of course) is needed.

    https://www.jpl.nasa.gov/news/news.php?release=2017-258

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  3. #783
    Join Date
    May 2005
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    7,542
    Another study shows that the dimming might be asymmetric or if it symmetric it might have a ten year or longer period.
    https://arxiv.org/abs/1710.05000
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