Photosphere - The photosphere is the deepest layer of the Sun that we can observe directly. It reaches from the surface visible at the center of the solar disk to about 250 miles (400 km) above that.

What is photosphere of the Sun?

The photosphere is the visible "surface" of the Sun. The Sun is a giant ball of plasma (electrified gas), so it doesn't have a distinct, solid surface like Earth. ... This level is what we see as the glowing "surface" of the Sun - the photosphere. The temperature of the photosphere is around 5,500° C (about 9,900° F).

Do all stars have a photosphere?

All stars have photospheres, although they are not all so thin as that of the Sun. ... The temperature at the center of a sunspot is about 2,000 degrees Kelvin lower than the surrounding gas in the photosphere, at 5,780 degrees Kelvin. While sunspots are dark, they still radiate light.