Jakob Bartsch was a German physician, professor of mathematics at the University of Strassburg (now Strasbourg), assistant to and son-in-law of Johannes Kepler, and author of various astronomical treatises. In 1624 he published three star charts, based on data supplied by Philipp Müller of Leipzig, which showed the stars of the northern hemisphere, the zodiac on a long strip, and the southern stars. Each map had two complimentary sheets showing the latitude and longitude, and the constellations, respectively. Bartsch is also credited with naming Crux, the Cross, by taking four stars from Ptolemy's original Centaurus. He died in Lauban, shortly after being called to Strasbourg as professor of astronomy.