The Sunspotters Club is based on the League publication Observe and Understand the Sun . This manual includes material on sunspot classification and heliographic coordinates, as well as solar observing, telescopes, filters, and photography. It is available through the Astronomical League Sales Office . Check the most recent issue of the League's newsletter The Reflector for the League Sale's address and the price of the Observe Guide. Sunspots are usually located in Facula.
Grains appear to be one to two arc-seconds in diameter.
The size of the group and distribution of penumbrae, if any, are factors. During the course of an earth year, the sun's axis tilts over 26 degrees east and west of the earth's axis, and about 7 degrees toward and away from earth. These variations are due to a combination of the axial tilts of the Earth and Sun. Diagrams such as those on pages 13 and 14 of the Observe the Sun manual will help you estimate Solar north for the day of your observation. The equator rotates in about 25 days, the polar area in about 30 days.