Watch for faculae at the edges, rather than the center, of the sun's disk. Limb darkening occurs because earthbound viewers can't see as deeply into the sun at the limbs, so we see higher, cooler, and thus dimmer regions. Each granule is a convective cell of heated gas measuring between 400 and 600 miles across. As the gas rises and reaches the top of the photosphere, it cools, then drops back into the photosphere to be reheated and recirculated, like a pot filled with cells of boiling water on a stove top. Granulation viewing requires at least a 3-inch telescope, 150x to 200x, and very stable atmospheric conditions.
Granulations are also nearly impossible to spot using solar projection methods.
The sun is an ideal amateur target for study through backyard telescopes. It is visible at a convenient hour. In-depth observations are possible without expensive equipment. As we approach maximum in the sunspot cycle , our star promises an interesting show. Employment Copyright 1996-2001 Kalmbach Publishing Co.