A simple flowchart to assist with classification of sunspots using the McIntosh system.
This is the original document by Patrick S. McIntosh (NOAA Space Environment Labs) originally published in Solar Physics 125: 251-267, 1990.
Originally published in the Journal of the British Astronomical Association, the paper describes how Sunspots are assessed and recorded for the BAA White Light database.
Authors: Frank J. Ventura and Tony Tanti
Original publication date: 1988 JBAA pages 282-286