Scheiner, Christoph (1573-1650)

German astronomer who carried out one of the earliest studies of sunspots and made significant improvements to the helioscope and the telescope. In about 1605 he invented the pantograph, an instrument used for copying plans and drawings to any scale.

Life Scheiner was born near Mindelheim, Bavaria, and studied at Ingolstadt, where he became professor of mathematics and Hebrew 1610. There he began to make astronomical observations and organized public debates on current issues in astronomy. In 1616 Scheiner was invited to the court in Innsbruck, Austria, and the following year he was ordained to the priesthood. From 1633 he lived in Vienna and from 1639 in Neisse (now Nysa in Poland).

Discovery of sunspots Scheiner built his first telescope in 1611, one of the first properly mounted telescopes. He projected the image of the Sun onto a white screen so that it would not damage his eyes. When he detected spots on the Sun, he believed they were small planets circling the Sun. His Jesuit superiors did not wish him to publish his observations in case he might discredit their order, so he communicated his discovery to a friend who under a pseudonym passed it on to astronomers Galileo and Kepler. Galileo nonetheless identified Scheiner and claimed priority for the discovery of sunspots, hinting that Scheiner was guilty of plagiarism. Scheiner also concluded that Venus and Mercury revolve around the Sun, but because of his religious beliefs, he did not extend this observation to the Earth.

Books In his Sol ellipticus 1615 and Refractiones caelestes 1617, Scheiner drew attention to the elliptical form of the Sun near the horizon, which he explained as being due to the effects of refraction. In his main work, Rosa ursina sive sol 1626-30, he accurately described the inclination of the axis of rotation of the sunspots to the plane of the ecliptic.