| Term: | active longitude |
| Definition: |
A range of heliographic longitudes in either the northern or southern solar hemisphere (seldom both at the same time) containing one or more large and complex active regions formed by the frequent, localized emergence of new magnetic flux. Individual sunspot groups within the complex can have relatively short lifetimes (a week or two); the complex may persist for several solar rotations because additional spot groups form as earlier ones decay. |