Post in forum #221228 - What makes you sad?

Snowy said:
Also the claim that the Sun is classified as an orange dwarf is a new one to me. I was taught (and every source that I can find sides with me on this) that the Sun is a G dwarf ("yellow dwarf"), not a K dwarf ("orange dwarf").


Actually you are right, thank you for the correction and sorry for the imprecise information.

Fenrick said:
The sun appears white if you look at photos of it from space. The atmosphere just makes it look orange.

Snowy said:
Many are, but they aren't true color. The sun is approximately (and it's a pretty good approximation) a black-body emitter, and it's emissions peak in the green part of the spectrum. A black body radiating strongly in the green is also radiating strongly in the rest of the visual spectrum, so it ends up looking white (a faintly yellowish white, but if you saw it directly (through a good neutral-density filter, hopefully!) you'd call it white).

Stars emit all wave-lenghts of visible light, the prevalence of a specific color varies mostly according the star's temperature, but they generally look white to the human eye. Specific filters are used in order to isolate the "signature bright" from a determined star, and the Sun is orange (actually it is more like amber, but I suppose you got the idea).

Curiously, a similar process was applied to the whole visible universe and the resulting (most commom) color was beige.