The Zurich Classification System of Sunspot Groups

"G", "H", and "J" Types

"H" Type: The decayed remnant of "C", "D", "E", and "F" groups. A single spot group with penumbra. Must be larger than two and one-half degrees in diameter. The "H" type occasionally is accompanied by a few small spots.

"J" Type: The same as the "H" type but has a diameter less than 2½ degrees.

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