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Drakkith
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Yes, which is a misnomer.davenn said:OK ... regardless of how it looks visually or photographically via the Earth's atmosphere,
The Sun is deemed a yellow class star...
The term yellow dwarf is a misnomer, as G stars actually range in color from white, for more luminous types like the Sun, to only slightly yellow for the less luminous GV stars.[8] The Sun is in fact white, but appears yellow through the Earth's atmosphere due to Rayleigh scattering. In addition, although the term "dwarf" is used to contrast yellow main-sequence stars from giant stars, yellow dwarfs like the Sun outshine 90% of the stars in the Galaxy (which are largely orange dwarfs, red dwarfs, and white dwarfs, the latter being a post-main-sequence star).
http://en.wikipedia.org/wiki/Yellow_dwarf
Solon said:@Drakkith.I've never seen a colour calibration card used out in orbit, or a white balance reference card. Maybe it's because colour being perceptive they don't bother?. SOLSPEC has 1 nm sampling, but calibration is needed regularly, and I don't see any charts showing how the spectrum changes, if it does, over time. Is ours a variable star?
No, the Sun is not a variable star.
While the Sun does go through changes, none of these have any effect on the average temperature of the Sun's photosphere, which means that it continually outputs light with a spectrum close to a perfect blackbody at about 5,800 kelvin.
I though they used light and colour curves when examining the Cephid variables? Maybe not.
To my knowledge they only measure the magnitude changes.
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