Johann Bayer in the context of "Hydrus"

Julius Schiller (c. 1580 – 1627) was a lawyer from Augsburg who, like his fellow citizen and colleague Johann Bayer, published a star atlas in celestial cartography.

In the year of his death, Schiller, with Bayer's assistance, published the star atlas Coelum Stellatum Christianum which replaced the pagan names of constellations with biblical and early Christian figures. Specifically, Schiller replaced the zodiacal constellations with the twelve apostles, the northern constellations by figures from the New Testament, and the southern constellations by figures from the Old Testament.

The Coelum Stellatum Christianum is a star atlas published in 1627 by Julius Schiller (c. 1580–1627), with the collaboration of Johann Bayer (1572–1625). In the treatise, which was published by Andreas Aperger at Augsburg during the same year as Schiller's death, pagan constellations were replaced with biblical figures and Christian motifs. Schiller replaced the zodiac constellations with the Twelve Apostles, the northern constellations with New Testament figures, and the southern constellations with Old Testament figures.

The planets, the Sun, and the Moon were also replaced by biblical figures:

The history of astronomy focuses on the efforts of civilizations to understand the universe beyond earth's atmosphere.Astronomy is one of the oldest natural sciences, achieving a high level of success in the second half of the first millennium. Astronomy has origins in the religious, mythological, cosmological, calendrical, and astrological beliefs and practices of prehistory. Early astronomical records date back to the Babylonians around 1000 BC. There is also astronomical evidence of interest from early Chinese, Central American and North European cultures.

Astronomy was used by early cultures for timekeeping, navigation, spiritual and religious practices, and agricultural planning. Ancient astronomers observed and charted the skies in an effort to learn about the workings of the universe. During the Renaissance Period, revolutionary ideas emerged about astronomy. One such idea was contributed in 1543 by Polish astronomer Nicolaus Copernicus, who developed a heliocentric model that depicted the planets orbiting the sun. This was the start of the Copernican Revolution, with the invention of the telescope in 1608 playing a key part. Later developments included the reflecting telescope, astronomical photography, astronomical spectroscopy, radio telescopes, cosmic ray astronomy, infrared telescopes, space telescopes,ultraviolet astronomy, X-ray astronomy, gamma-ray astronomy, space probes, neutrino astronomy, and gravitational-wave astronomy.

In astronomy, stars have a variety of different stellar designations and names, including catalogue designations, current and historical proper names, and foreign language names.

Only a tiny minority of known stars have proper names; all others have only designations from various catalogues or lists, or no identifier at all. Hipparchus in the 2nd century BC enumerated about 850 naked-eye stars. Johann Bayer in 1603 listed about twice this number. Only in the 19th century did star catalogues list the naked-eye stars exhaustively. The Bright Star Catalogue, which is a star catalogue listing all stars of apparent magnitude 6.5 or brighter, or roughly every star visible to the naked eye from Earth, contains 9,096 stars. The most voluminous modern catalogues list on the order of a billion stars, out of an estimated total of 200 to 400 billion in the Milky Way.

In Greek mythology, Orion (/əˈraɪən/; Ancient Greek: Ὠρίων or Ὠαρίων; Latin: Orion) was a giant huntsman whom Zeus (or perhaps Artemis) placed among the stars as the constellation of Orion.

Ancient sources told several different stories about Orion; there are two major versions of his birth and several versions of his death. The most important recorded episodes are his birth in Boeotia, his visit to Chios where he met Merope and raped her, being blinded by Merope's father, the recovery of his sight at Lemnos, his hunting with Artemis on Crete, his death by the bow of Artemis or the sting of the giant scorpion which became Scorpius, and his elevation to the heavens. Most ancient sources omit some of these episodes and several tell only one. These various incidents may originally have been independent, unrelated stories, and it is impossible to tell whether the omissions are simple brevity or represent a real disagreement.

Uranometria is a star atlas produced by Johann Bayer. It was published in Augsburg in 1603 by Christoph Mang (Christophorus Mangus) under the full title Uranometria: omnium asterismorum continens schemata, nova methodo delineata, aereis laminis expressa (from Latin: Uranometria, containing charts of all the constellations, drawn by a new method and engraved on copper plates). The word "uranometria", from Ancient Greek οὐρανός (ouranós) 'sky, heavens' and μέτρον (metron) 'measure', literally translates to "measuring the heavens".

It was the first atlas to cover the entire celestial sphere.

A Bayer designation is a stellar designation in which a specific star is identified by a Greek or Latin letter followed by the genitive form of its parent constellation's Latin name. The original list of Bayer designations contained 1564 stars. The brighter stars were assigned their first systematic names by the German astronomer Johann Bayer in 1603, in his star atlas Uranometria. Bayer catalogued only a few stars too far south to be seen from Germany, but later astronomers (including Nicolas-Louis de Lacaille and Benjamin Apthorp Gould) supplemented Bayer's catalog with entries for southern constellations.

Volans is a constellation in the southern sky. It represents a flying fish; its name is a shortened form of its original name, Piscis Volans. Volans was one of twelve constellations created by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman and it first appeared on a 35-cm (14") diameter celestial globe published in 1597 (or 1598) in Amsterdam by Plancius with Jodocus Hondius. The first depiction of this constellation in a celestial atlas was in Johann Bayer's Uranometria of 1603.

Triangulum is a small constellation in the northern sky. Its name is Latin for "triangle", derived from its three brightest stars, which form a long and narrow triangle. Known to the ancient Babylonians and Greeks, Triangulum was one of the 48 constellations listed by the 2nd century astronomer Ptolemy. The celestial cartographers Johann Bayer and John Flamsteed catalogued the constellation's stars, giving six of them Bayer designations.

The white stars Beta and Gamma Trianguli, of apparent magnitudes 3.00 and 4.00, respectively, form the base of the triangle and the yellow-white Alpha Trianguli, of magnitude 3.41, the apex. Iota Trianguli is a notable double star system, and there are three star systems with known planets located in Triangulum. The constellation contains several galaxies, the brightest and nearest of which is the Triangulum Galaxy or Messier 33—a member of the Local Group. The first quasar ever observed, 3C 48, also lies within the boundaries of Triangulum.

Canis Minor is a small constellation in the northern celestial hemisphere. In the second century, it was included as an asterism, or pattern, of two stars in Ptolemy's 48 constellations, and it is counted among the 88 modern constellations. Its name is Latin for "lesser dog", in contrast to Canis Major, the "greater dog"; both figures are commonly represented as following the constellation of Orion the hunter.

Canis Minor contains only two stars brighter than the fourth magnitude, Procyon (Alpha Canis Minoris), with a magnitude of 0.34, and Gomeisa (Beta Canis Minoris), with a magnitude of 2.9. The constellation's dimmer stars were noted by Johann Bayer, who named eight stars including Alpha and Beta, and John Flamsteed, who numbered fourteen. Procyon is the eighth-brightest star in the night sky, as well as one of the closest. A yellow-white main-sequence star, it has a white dwarf companion. Gomeisa is a blue-white main-sequence star. Luyten's Star is a ninth-magnitude red dwarf and the Solar System's next closest stellar neighbour in the constellation after Procyon. Additionally, Procyon and Luyten's Star are only 1.12 light-years away from each other, and Procyon would be the brightest star in Luyten's Star's sky. The fourth-magnitude HD 66141, which has evolved into an orange giant towards the end of its life cycle, was discovered to have a planet in 2012. There are two faint deep-sky objects within the constellation's borders. The 11 Canis-Minorids are a meteor shower that can be seen in early December.

Tucana (The Toucan) is a constellation in the southern sky, named after the toucan, a South American bird. It is one of twelve constellations conceived in the late sixteenth century by Petrus Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. Tucana first appeared on a 35-centimetre-diameter (14 in) celestial globe published in 1598 in Amsterdam by Plancius and Jodocus Hondius and was depicted in Johann Bayer's star atlas Uranometria of 1603. French explorer and astronomer Nicolas Louis de Lacaille gave its stars Bayer designations in 1756. The constellations Tucana, Grus, Phoenix and Pavo are collectively known as the "Southern Birds".

Tucana is not a prominent constellation as all of its stars are third magnitude or fainter; the brightest is Alpha Tucanae with an apparent visual magnitude of 2.87. Beta Tucanae is a star system with six member stars, while Kappa is a quadruple system. The constellation contains 47 Tucanae, one of the brightest globular clusters in the sky, and most of the Small Magellanic Cloud.