From Today in Science History:
Johannes Fabricius. Born 8 Jan 1587; died c. 1615.
Dutch(sic) astronomer who was perhaps the first to observe sunspots. On 9 Mar 1611, at dawn, Johannes directed his telescope at the rising sun and saw several dark spots on it. He called his father to investigate this new phenomenon with him. The brightness of the Sun’s center was very painful, and the two quickly switched to a projection method by means of a camera obscura. Johannes was the first to publish information on such observations. He did so in his Narratio de maculis in sole observatis et apparente earum cum sole conversione. (“Narration on Spots Observed on the Sun and their Apparent Rotation with the Sun”), the dedication of which was dated 13 Jun 1611. He died aged 29.
Read more about his place in the history of astronomy at The Galileo Project