Can't we use temperature to predict luminous intensity, then compare that to actual to find emissivity?The sun is too far away to do reflectivity measurements of its surface, and there isn't a source around with enough light to measure the reflectivity of the sun. For the planets in the solar system, as well as the earth's moon, the light from the sun can be used to measure their reflectivity throughout the spectrum radiated by the sun. ## \\ ## I do believe the surface of the sun may be close to a blackbody, both in the visible as well as the infrared, because of the plasma nature of its surface that makes for good electromagnetic absorption, but I don't know of any way presently that can be used to make a reflectivity measurement.
In other words, pretty close, but not as close asCan't we use temperature to predict luminous intensity, then compare that to actual to find emissivity?
View attachment 229943
Seems pretty close to blackbody to me.Googling, I find values around 0.985.