With the telescope, seventeenth-century astronomers could observe the night sky as never before. Some made detailed studies of passing comets and the planets, Sun, and Moon, including German Jesuit Christoph Scheiner, who observed sunspots for over 20 years, and Polish brewer Johannes Hevelius, who produced the first accurate, highly-detailed map of the Moon. German lawyer Johann Bayer published a highly-detailed atlas of the constellations, as did other astronomers, including Hevelius. At his home in Danzig, Hevelius built a large observatory on the rooftop of three adjoining properties, where he devoted decades to compiling a catalogue of star positions.
As European explorers sailed into the Southern Hemisphere, they created new constellations which were added to these celestial maps. The first to systematically observe the southern stars was Edmund Halley (for whom Halley’s Comet is named). In 1676, at the age of 20, Halley traveled to the island of St. Helena off the African coast with a telescope and other instruments, producing a catalogue of nearly 350 stars. He published his charts and observations in 1679.
Other important astronomical findings of the latter half of the seventeenth century include the discovery of Saturn’s ring system by Dutch astronomer Christiaan Huygens, and the discovery of the Saturn’s first four moons by Italian-French astronomer Giovanni Cassini.
Johannes Hevelius. Catalogus stellarum fixarum (Fixed star catalog). 1660-1681.
One of BYU’s most important astronomy holdings is the manuscript of Hevelius’ star catalog, which he compiled between the years 1660 and 1681. It consists of handwritten tables of Hevelius’ systematic measurements of celestial bodies, with a comparison to the measurements of other astronomers, including Tycho and Ptolemy. The star catalog was not published until nearly two centuries after Hevelius’ death.
Johannes Hevelius. Selenographia (A Description of the Moon). Danzig: Hünefeld, 1647.
Hevelius’ description of lunar topography includes three engravings which are considered the first true maps of the Moon. Hevelius engraved the plates himself, and employed his own printer to issue his work.
Johannes Hevelius. Firmamentum Sobiescianum: sive, Uranometria (Sobieski’s Firmament) Danzig: J.Z. Stallis, 1690.
This celestial atlas contains large-format engravings of the constellations. The maps of the northern stars are based on Hevelius’ own measurements and the maps of the southern stars were based on Edmund Halley’s measurements. Firmamentum Sobiescianum is dedicated to the Polish king, Jan III Sobieski, who commanded the army which successfully defended Vienna against an Ottoman siege in 1683.
Christoph Scheiner. Rosa Ursina. Bracciano: Andrea Phaeus, 1626-1630.
Rosa Ursina is the culmination of Scheiner’s decades-long study of sunspots, and contains many large engravings illustrating his observations and the instruments and methods which he employed.