Named for Sigfrid Aronus Forsius (c. 1550–1624), pastor, naturalist and astronomer. Among his various life-works he was rector of several parishes, mapped the Tornio river valley (1601–1602), was professor of astronomy at Uppsala University (1608–1610), and prepared almanacs for the horizons of Stockholm and Turku, from 1613 as a monopoly. (M 18450) _ _.