Modern, European, Western, not Ptolemaic

  • Chet Raymo, 365 Starry Nights

    Short introductions to the night sky in astronomy, literature and mythology for every night of the year.  Use an app like StarWalk or SkySafari to find the constellations outside at night, but use this book to take your first steps to learn about them.  It is an ideal family read-aloud, appropriate for a variety of ages, year after year, or use it as a supplement to an astronomy textbook to rekindle a sense of wonder at the universe.

    Here at The Sky Tonight, many of our Constellation pages are keyed to Raymo's 365 Starry Nights.

    The simplicity of 365 Starry Nights is also its virtue.  It is organized only according to day and month of the year.  

    The following index of constellations will aid in navigation for quick reference.

  • H.A. Rey, The Stars

    A true classic:  This introductory work, by the author of the Curious George stories for children, has introduced more young people to the constellations and enjoyment of the night sky than any other book.  Rey's stick figures representing the constellations are creative and whimsical, and above all memorable, even though sometimes they take liberties with the historical names of stars.

  • Galileo, Sidereus Nuncius

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    When Galileo observed the belt and sword of Orion the Hunter, and the Pleiades star cluster on the back of Taurus the Bull, the background of night gave way before his eyes: His telescope resolved an astonishing number of unexpected stars never seen before. 

    On one page he shows 36 new stars around the original six of the Pleiades, and on another, 80 new stars near the belt and sword of Orion. What if uncountable stars might exist, much farther away than was previously believed? How plausible would it be for an immense and vastly thick sphere of stars to rotate every 24 hours around a tiny central, stationary Earth?

    “For the Galaxy is nothing else than a congeries of innumerable stars distributed in clusters. To whatever region of it you direct your spyglass, an immense number of stars immediately offer themselves to view, of which very many appear rather large and very conspicuous but the multitude of small ones is truly unfathomable.”
    Galileo, Sidereus Nuncius
    trans. Albert Van Helden (University of Chicago, 1989).


  • Bayer, Uranometria

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    In contrast to Piccolomini, who omitted constellation figures in favor of scientific accuracy, Bayer superimposed constellation figures upon the star maps without compromising positional accuracy. These figures were artfully drawn by Alexander Mair. By fusing science and art, merging true star maps with innovative constellation figures, Bayer inaugurated the golden age of the celestial atlas.

    First published in Augsburg in 1603, Bayer’s atlas consists of 51 double-page copperplate engravings. Bayer plotted his stars on a coordinate grid with one-degree intervals. His own star catalog, bound at the front of this volume, is based on the star positions of Tycho Brahe. 

    A dark horizontal band runs through all the constellations of the Zodiac, where the planets move against the background of fixed stars.  Bayer depicted the band 8 degrees above and below the ecliptic, or annual path of the Sun. For example, in the constellation of Taurus the Bull, the ecliptic runs across the page in the center of the Zodiac horizontal band.  The Milky Way angles down the left side.

    Bayer labeled the stars with Greek letters, according to their apparent magnitude, so that the brightest star in Taurus, Aldebaran, is alpha-Tauri. This convention is still used today.

    Bayer’s atlas consists of 51 double-page copperplate engravings, including 2 planispheres, one star map for each of the 48 Ptolemaic constellations, and one map for 12 new constellations of the southern skies reported by 16th-century explorers (cf. the discussion of the southern stars plate in Ridpath Star Tales.)

    The 1603 1st edition printed both sides of the leaves.  In this later edition, the absence of printed text on the back side of each leaf prevented type from showing through on the atlas pages.  Each double-page atlas leaf is attached to a strip of scrap paper that is bound in the gutter, so that the atlas image itself does not disappear down into the fold.

    Bayer showed the star positions as they appear from the Earth (rather than from the outside, as on a celestial globe). However, he sometimes reversed the constellation figures, drawing them as seen from the back, which created potential confusion. For example, the star Rigel, described by Ptolemy as the left foot of Orion, became Orion’s right foot in Bayer’s figure, even though the star pattern remained the same as seen from Earth.

    In the star catalog bound at the front of the OU copy, each star is listed along with its number from Ptolemy’s star catalog, and with the Greek letter assigned to it by Bayer to represent its brightness. Tycho’s star catalog included about 1,000 stars. Bayer incorporated many of these and added about 1,000 of his own, for a total of about 1,700 stars.  A bright circle in the constellation of Cassiopeia shows where a nova appeared in 1572, described by Tycho Brahe.

  • Kepler, De stella nova

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    Kepler’s star map shows the constellations of Ophiuchus (the Serpent Handler), Sagittarius and Scorpius. The Milky Way runs diagonally down from the left, and the “ecliptic,” or annual path of the Sun, runs horizontally through Sagittarius and Scorpius. 

    A triple conjunction of Jupiter and Saturn took place in 1603, followed by a planetary massing with Mars in 1604. After the planetary massing, a “Nova” or bright star (“N”) suddenly appeared in the ankle of Ophiuchus on October 10, 1604. 

    The new star was no ordinary star; it remained visible even in the daytime sky for over a year. The new star prompted widespread debate about what it might portend and whether the heavens could change. Now called Kepler’s nova, it was the second supernova to be observed in a generation, after the supernova in Cassiopeia, described by Tycho, which appeared in 1572. 

    No supernova within the Milky Way galaxy has been observed since.

    Kepler’s star positions and artistic style show the influence of Tycho and Bayer. Bayer had reversed a number of constellation figures, including Orion and Ophiuchus. In contrast, Kepler’s map shows the figure of Ophiuchus facing toward us rather than outward, so that the traditional star names of his feet and shoulders match the orientation of the constellation figure.

    Aristotle taught that conjunctions and planetary massings produce comets. Here, less ominously, they seemed to have produced a new star.  

    Kepler mused that this new star might have been caused by the planets’ proximity, might portend the fall of the Turks, or perhaps the second advent of Christ. Above all, he forecast that it would result in good business for booksellers, as a rash of hastily produced pamphlets would be rushed into print to explain it! Or maybe, he wondered, something similar might have happened for the Bethlehem Star. Some variation of Kepler’s account is the most common explanation of the Star of Bethlehem offered in planetarium shows and astronomer talks today.

    In this book, Kepler also discussed mathematical chronology, the date of the birth of Christ, and the nature of the Star of Bethlehem. 

  • Lubieniecki, Theatrum cometicum

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    The search for comets, charged with astrological meaning, stimulated careful scrutiny and revision of maps of the stars. Lubieniecki collected an anthology of cometary reports, attempting to describe every known comet observed in Europe up to 1665. 

    A comet which appeared in 1664-1665 prompted more than 40 reports from various observers, including Hevelius. 

    Contributors took varying approaches to observation and artistic design in their reports. Some comet watchers took care with the aesthetic depiction of constellation figures. Others did not. Very few adopted Bayer’s star numbering system. Neither the style of constellation figures nor the names and boundaries of the constellations were consistent. The resulting theater of comets reflects the variety of astronomical practices and observers in 17th century Europe. 

  • Hevelius, Uranographia

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    The Uranographia of Hevelius, the most detailed and influential celestial atlas of the 17th century, contains 54 beautiful double-page engraved plates of 73 constellations, and 2 oversized folding plates of planispheres.

    The frontispiece of Hevelius’ star atlas shows Hevelius bringing his modest gifts before a tribunal of great figures in the history of astronomy. These gifts are his proposed new constellations: the shield and sextant he carries, and the animals trailing behind him. Of the 12 constellations Hevelius created, 7 are still recognized today. One is the Lynx, in recognition of the far-seeing eyes of astronomers. He named Scutum the Shield in honor of the Polish king.

    The new Sextant constellation represented a large instrument which he and his astronomer wife Elisabeth used to determine star positions.

    Unique among the major star atlases, Hevelius depicted the star patterns as if from the outside looking in, not as seen when looking up into the night-time sky. Consequently, Hevelius’ constellation figures provided an influential model for the production of artfully-designed celestial globes.

    The full title of the Uranographia pays tribute to the Polish king, John III Sobiesci. Hevelius created a new constellation, Scutum, the “Shield of Sobiesci,” representing the king’s defense of Europe against the Turks.

    In the Prodromus, Hevelius explained the instruments and methods used to produce the star catalog. Their Gdansk observatory, “Stellaburg,” was the best in Europe until the later national observatories of France and Britain. Inspired by Tycho Brahe, Hevelius constructed large precision observing instruments, including a great sextant for measuring the angular distance of any star from nearby reference stars.

    In the frontispiece to the Prodromus, Hevelius joins the table of Urania, the Muse of astronomy, around which are seated a select number of great figures in the history of astronomy: Ptolemy; Tycho Brahe; Ulugh Beg; Henry of Langenstein (Landgrave of Hesse); and Giambattista Riccioli.

    The star catalog includes ecliptic and equatorial coordinates for 1,564 stars, about 600 of which were new. Hevelius based their positions on his own observations, supplemented by Edmond Halley’s catalog of southern stars. 

    Tragically, in 1679 their observatory burned (as recounted in the book, Annus Climacteris). Fire destroyed manuscripts, books and instruments, including the sextant. Johann was 67 years old, and passed away six years later. Later, Elisabeth published the star catalog and celestial star atlas.

  • Coronelli, Celestial Globe Gores

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    Coronelli, a Franciscan theologian and astronomer who worked in both Italy and France, was a founder of modern geography and an influential maker of celestial and terrestrial globes. Makers of globes printed sheets of map sections, called gores, which were then hand-colored, cut out and glued onto a wood and paper-maché base. 

    These 9 gores were part of a set of 24 produced at the request of Coronelli’s Accademia Cosmografica to make a 3.5 foot diameter celestial globe. They were designed by Arnold Deuvez and engraved by Jean-Baptiste Nolin in Paris. The set was a reprint of gores which Coronelli printed in Venice in 1688. At the time, Coronelli’s 1688 globe was the largest and most accurate printed celestial globe. The Latin and French legends distinguish this 1693 Paris reprint from the 1688 originals, which were in Italian.

    These gores are reprints made in 1800 using the original 1693 plates.

    In the Epitome Cosmographica, Coronelli explained how to use celestial and terrestrial globes and his techniques for constructing them. The Epitome describes how Coronelli famously constructed a pair of terrestrial and celestial globes for Louis XIV which measured more than 12 feet in diameter. 

  • Flamsteed, Atlas coelestis

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    Flamsteed was England’s first Astronomer Royal, charged with improving star positions accurately enough to determine longitude at sea. In 1676, he completed the building of the Greenwich Observatory. 

    Flamsteed’s star atlas, posthumously published, became the most celebrated and influential star atlas of the 18th century. At the time, it was the largest star atlas ever printed. Its 28 copperplate engravings include 25 double-page star charts and 2 double-page planisphere maps. 

    Constellation figures are viewed from the front, matching the traditional names of stars. Sir James Thornhill was among the artists who designed the constellation figures in a Rococo style that was soon copied in Paris and Berlin. 

    Flamsteed determined star positions using observing instruments equipped with telescopic sights (a first among major atlases). 

    Isaac Newton relied on Flamsteed’s star coordinates, made available to him at an earlier date, for his theory of universal gravitation and explanation of the motion of the Moon. 

    More than 3,000 stars are presented, double the number in Hevelius.

    A Note on Celestial Coordinates

    Earlier atlases were based on the great circle of the Sun’s annual path around the sky, called the “ecliptic.” Celestial “longitude” measures in degrees along the ecliptic, and celestial “latitude” measures in degrees perpendicular to the ecliptic. The ecliptic is angled at 23.5 degrees from the Earth’s equator. Because the ecliptic and the Earth’s equator do not coincide, celestial latitude and celestial longitude do not coincide with terrestrial latitude and longitude.

    Flamsteed’s atlas was the first major atlas to use a grid based not on the ecliptic, but on the Earth’s geographical coordinates. Flamsteed thus introduced the convention now used in modern star atlases where the Earth’s equator, projected into the sky as the celestial equator, is (now) marked off in “hours” and “minutes” of “Right Ascension,” corresponding to terrestrial longitude. The Earth’s latitude circles are projected into the sky as circles of “Declination,” measured in degrees north or south of the celestial equator. 

  • Bode, Uranographia

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    This magnificent atlas fused artistic beauty and scientific precision. Bode, director of the Observatory of the Berlin Academy of Sciences, produced the last of the four major celestial atlases in which artful depictions of constellation figures appear alongside the most up-to-date scientific data. 

    20 large copperplate engravings plot more than 17,000 stars, far more than any previous atlas. Bode included new stars for the southern hemisphere, along with constellations recently invented by Hevelius and Lacaille. 

    Bode depicted more than 100 constellations, compared with 88 officially recognized today. Some which appeared in this atlas for the first time, but are not officially recognized today, include the Cat, the Printing Press, the Montgolfier Balloon, and the Electric Generator. 

    Bode also included 2,500 cloudy patches, or “nebula,” cataloged by William Herschel.


    Bode included two planisphere plates.  They are not southern and northern hemispheres; each one has Polaris at the top and the south pole at the bottom.  Each one is centered upon an equinox point (where the ecliptic or path of the Sun and the celestial equator intersect).  The March equinox point was in Aries in antiquity; by Bode’s time, due to the precession of the equinoxes, it had shifted to Pisces.  The September equinox point was in Libra in antiquity; by Bode’s time it had shifted to Virgo.  Bode titled the plates as the Aries and Libra planispheres. 

    The Aries planisphere, centered on the March equinox in Pisces, includes these constellations, among others, which appear high overhead in the night skies of autumn:  

    • Equatorial:  Orion, Taurus, Harpa Georgii, Cetus, Aries, Pisces, Pegasus, Aquarius, Aquila, Scutum.
    • Northern:  Auriga, Perseus, Andromeda, Cassiopeia, Draco, Honores Frederici, Cepheus, Cygnus, Lyra.
    • Southern:  Eridanus, Apparatus Chemicus, Machina Electrica, Apparatus Sculptoris, Horologium, Toucan, Phoenix, Grus, Indus, Pavo, Tubus Astronomicus, Octans Nautica, Microscopium, Sagittarius, Globus Aerostatic.

    In March, the Aries-Pisces equinox (the center of the Aries planisphere) is traveling with the Sun, rising in the east in the mornings and setting in the west in the evenings.  Imagine the center of the planisphere has the Sun pinned to it for that day, and that’s how it would move across the sky.  Therefore the constellations near the center of this planisphere are invisible in the daytime sky at that time.

    The Libra planisphere, centered on the September equinox in Virgo, includes these constellations, among others, which appear high overhead in the night skies of spring:

    • Equatorial:  Ophiuchus, Serpens, Libra, Virgo, Crater, Corvis, Hydra, Sextans, Leo, Cancer, Monoceros.
    • Northern:  Hercules, Quadrans Muralis, Bootes, Canes Venatici, Ursa Major, Telescopium Herschelii, Gemini, Lynx, Ursa Minor.
    • Southern:  Scorpius, Tubus Astronomicus, Lupus, Centaurus, Apis, Chameleon, Crux, Argo Navis, Robur Caroli II, Circinus (sector compass), Canis Major, Pixis Nautica (magnetic compass), Machina Pneumatica (air pump), Officina Typographica (printing press).

    In September, the Libra-Virgo equinox (the center of the Libra plate) is traveling with the Sun, rising in the east in the morning and setting in the west in the evening.  Imagine the center of the planisphere has the Sun pinned to it for that day, and that’s how it would move across the sky.  Therefore the constellations near the center of this planisphere are invisible in the daytime sky at that time.

    Earlier, in 1782, Bode published a small-format atlas based on a Paris edition of Flamsteed.

    The four great celestial atlases of Bayer, Hevelius, Flamsteed and Bode were each distinctive in their artistic style as well in their scientific importance. After Bode, this fusion of art and science in celestial atlases ceased, as scientific atlases no longer held room to include artistic constellation figures.