How do you know the sun is hot or warm?

Question

sunny cloudy

Answer 1

It omits heat.

Answer 2

Well, the first indication was that it got really hot during the day on Earth, when you could see the Sun in the sky, and it got cold when the Sun went away.  But one of the ways we can measure the temperature of different layers of the Sun is by taking a spectra - breaking the light up into it's colors like a prism.  Every colors is unique to an element.  The hotter the element is, the more colors it emits (higher electronic transitions), so if we see certain colors we know that, say, the iron on the Sun is around 4500 degrees at the surface.