Photosphere

Although we refer to the photosphere as a layer of the Sun, it is really a part of the Sun's atmosphere.  It is a very thin layer in comparison with the rest of the Sun, and is the only part of the Sun that we can actually see when looking at it from Earth, because it is where the light comes from.  (But of course you should never look straight at the Sun!)

In the photosphere, granulation, supergranulation, faculae, and sunspots are seen.

Sunspots

These are seen as dark spots in the photosphere that have extremely high magnetic fields.  They usually show up in groups of two sets and have a lower temperature than their surroundings.  This gives them a darkened appearance.  To the right is a very close-up image of a sunspot.

Faculae

Instead of appearing dark like sunspots, faculae show up as bright spots on the photosphere.  This is because they are hotter than their surroundings.  They aremagnetic also, but their magnetism is more concentrated than that of sunspots.  The bright spots in the images to the right are faculae.

 

Granulation

Granules are related to the convective zone.  The granulation that shows up in the photosphere is a result of the rising and falling of hot gas that takes place in the convective zone.  The bubbles seen are the material that reaches the top of the convective zone--the photosphere.  (For a better understanding and an image of granulation, check out the page on the convective zone.)

Supergranulation

Supergranules are just larger version of granules.  They have magnetic field "bunches" that flow within them.  Supergranules look similar to granules, except that they are 35,000 kilometers across as opposed to 1,000 kilometers across.