De Astronomica, or the Astronomy, also known as Poeticon Astronomicon,  is a book of stories whose text is attributed to "Hyginus", though the true authorship is disputed. During the Renaissance [ citation needed ], the work was attributed to the Roman historian Gaius Julius Hyginus who lived during the 1st century BC. However, the fact that the book lists most of the constellations north of the ecliptic in the same order as Ptolemy's Almagest (written in the 2nd century) has led many to believe that a more recent Hyginus or Pseudo-Hyginus created the text.
The text describes 47 of the 48 Ptolemaic constellations, centering primarily on the Greek and Roman mythology surrounding the constellations, though there is some discussion of the relative positions of stars. The first known printing was in 1475, attributed to "Ferrara."
The De Astronomica was not formally published until 1482, by Erhard Ratdolt in Venice. This edition carried the full title Clarissimi Viri Hyginii Poeticon Astronomicon Opus Vtilissimum. Ratdolt commissioned a series of woodcuts depicting the constellations to accompany Hyginus's text. As with many other star atlases that would follow it, the positions of various stars are indicated overlaid on the image of each constellation. However, the relative positions of the stars in the woodcuts bear little resemblance to the descriptions given by Hyginus in the text or the actual positions of the stars in the sky. 
As a result of the inaccuracy of the depicted star positions and the fact that the constellations are not shown with any context, the De Astronomica is not particularly useful as a guide to the night sky. However, the illustrations commissioned by Ratdolt served as a template for future sky atlas renderings of the constellation figures. The text, by contrast, is an important source, and occasionally the only source, for some of the more obscure Greek myths.
A constellation is an area on the celestial sphere in which a group of visible stars forms a perceived outline or pattern, typically representing an animal, mythological person or creature, or an inanimate object.
In Greek mythology, Callisto or Kallisto was a nymph, or the daughter of King Lycaon; the myth varies in such details. She was one of the followers of Artemis who attracted Zeus. According to some writers, Zeus transformed himself into the figure of Artemis to lure Callisto and seduce her. She became pregnant and when this was eventually discovered, she was expelled from Artemis's group, after which a furious Hera, the wife of Zeus, transformed her into a bear. Later, just as she was about to be killed by her son when he was hunting, she was set among the stars as Ursa Major. She was the bear-mother of the Arcadians, through her son Arcas by Zeus.
In Greek mythology, Eos is a Titaness and the goddess of the dawn, who rose each morning from her home at the edge of the Oceanus.
Pisces is a constellation of the zodiac. Its vast bulk – and main asterism viewed in most European cultures per Greco-Roman antiquity as a distant pair of fishes connected by one cord each that join at an apex – are in the Northern celestial hemisphere. Its name is the Latin plural for fish. It is between Aquarius, of similar size, to the southwest and Aries, which is smaller, to the east. The ecliptic and the celestial equator intersect within this constellation and in Virgo. This means the sun passes directly overhead of the equator, on average, at approximately this point in the sky, at the March equinox.
Virgo is one of the constellations of the zodiac. Its name is Latin for virgin, and its symbol is . Lying between Leo to the west and Libra to the east, it is the second-largest constellation in the sky and the largest constellation in the zodiac. The ecliptic intersects the celestial equator within this constellation and Pisces. Underlying these technical two definitions, the sun passes directly overhead of the equator, within this constellation, at the September equinox. Virgo can be easily found through its brightest star, Spica.
Astraea, Astrea or Astria, in ancient Greek religion, is a daughter of Astraeus and Eos. She is the virgin goddess of justice, innocence, purity and precision. She is closely associated with the Greek goddess of justice, Dike. She is not to be confused with Asteria, the goddess of the stars and the daughter of Coeus and Phoebe. The main belt asteroid 5 Astraea is named after her, and her name was also suggested for the planet Uranus.
Gaius Julius Hyginus was a Latin author, a pupil of the scholar Alexander Polyhistor, and a freedman of Caesar Augustus. He was elected superintendent of the Palatine library by Augustus according to Suetonius' De Grammaticis, 20. It is not clear whether Hyginus was a native of the Iberian Peninsula or of Alexandria.
In Greek mythology, Orion was a giant huntsman whom Zeus placed among the stars as the constellation of Orion.
In Greek mythology, the Hyades are a sisterhood of nymphs that bring rain.
The Catasterismi or Catasterisms, is a lost work attributed to Eratosthenes of Cyrene. It was a comprehensive compendium of astral mythology including origin myths of the stars and constellations. Only a summary of the original work survives, called the Epitome Catasterismorum, by an unknown author sometimes referred to as pseudo-Eratosthenes.
Ladon was a monster in Greek mythology.
A star chart or star map, also called a sky chart or sky map, is a map of the night sky. Astronomers divide these into grids to use them more easily. They are used to identify and locate constellations and astronomical objects such as stars, nebulae, and galaxies. They have been used for human navigation since time immemorial. Note that a star chart differs from an astronomical catalog, which is a listing or tabulation of astronomical objects for a particular purpose. Tools utilizing a star chart include the astrolabe and planisphere.
Celestial cartography, uranography, astrography or star cartography is the fringe of astronomy and branch of cartography concerned with mapping stars, galaxies, and other astronomical objects on the celestial sphere. Measuring the position and light of charted objects requires a variety of instruments and techniques. These techniques have developed from angle measurements with quadrants and the unaided eye, through sextants combined with lenses for light magnification, up to current methods which include computer-automated space telescopes. Uranographers have historically produced planetary position tables, star tables, and star maps for use by both amateur and professional astronomers. More recently, computerized star maps have been compiled, and automated positioning of telescopes uses databases of stars and of other astronomical objects.
Leiden, Universiteitsbibliotheek, VLQ 79, also called the Leiden Aratea, is an illuminated copy of an astronomical treatise by Germanicus, based on the Phaenomena of Aratus. The manuscript was created in the region of Lorraine and has been dated to around 816. It was produced at the court of Louis the Pious, who ruled from 814–840. It is one of the four Carolingian codices that were produced in his court. There are many translations and copies of this text, so it is very well known throughout the Middle East and Europe.
Orion's Sword is a compact asterism in the constellation Orion. It comprises three stars and M42, the Orion Nebula, which together are thought to resemble a sword or its scabbard. This group is south of the prominent asterism, Orion's Belt. Fables and old beliefs are in Europe dominated or widely influenced by those of the Greco-Roman narratives. Beyond Europe this grouping is quite widely referenced as a weapon just as the majority of cultures perceived Orion's standout asymmetrical "hourglass" of seven very bright stars as a human.
In Greek mythology, Aega or Pine or Cynosura or Melissa was, according to Hyginus, a daughter of Olenus, who was a descendant of Hephaestus. Aega and her sister Helice nursed the infant Zeus in Crete, and the former was afterwards changed by the god into the constellation called Capella.
In Greek mythology, Merope is one of the seven Pleiades, daughters of Atlas and Pleione. Pleione, their mother, is the daughter of Oceanus and Tethys and is the protector of sailors. Their transformation into the star cluster known as the Pleiades is the subject of various myths.
In Greek mythology, Paeon or Paion was a son of Poseidon by Helle, who fell into the Hellespont. In some legends he was called Edonus. He was the brother of the giant Almops.
In Greek mythology, Erigone was the daughter of Icarius of Athens.
Cassiopeia or Cassiepeia (Κασσιέπεια), a figure in Greek mythology, was Queen of Aethiopia and wife of King Cepheus. She was arrogant and vain, characteristics that led to her downfall. Her name in Greek is Κασσιόπη, Kassiope; other variants are Κασσιόπεια, Kassiopeia and Κασσιέπεια, Kassiepeia.