Celestial Cartography – Maps of the Heavens
With the invention of printing in the 15th Century, it was only a matter of time until maps and globes became commonplace. Printed maps of the world were soon supplemented with maps of countries and of towns. These were then assembled into terrestrial atlases.
Old maps are valued today not just for their beauty, but because they show how our knowledge of geography advanced over the centuries. Cities grew and the boundaries between countries changed over time. And the art of mapmaking itself evolved over time. The quality and accuracy of terrestrial maps make for a fascinating study of man’s quest for knowledge of the world.
Maps of the heavens followed a similar journey. Man’s knowledge of the heavens and the accuracy of celestial maps and atlases have marched hand in hand over the centuries. Charts of the sky were followed with charts of the constellations which were then collected into celestial atlases. The charts and atlases on display here chronicle this journey. Along with advances in scientific knowledge, celestial maps represent some of the most beautiful and artistic creations in the history of map making.
A Brief History of Printed Star Atlases
16th Century: Rough Beginnings, Ancient Origins
The earliest printed depictions of the constellations were not true maps of the sky. Constellation figures were produced as woodcut diagrams with stars positioned to adorn the figures, but these star were not positioned to accurately portray the heavens.
It was not until 1515 that the first printed maps of the heavens appeared that accurately portrayed the night sky. In that year, the celebrated artist Albrecht Dürer produced a pair of woodcut northern and southern planispheres (hemispherical views of half the heavens). His planispheres included a coordinate system and attempted to accurately position the stars of the 48 constellations based on the star catalog contained in Ptolemy’s 2nd century Almagest. The Almagest had been passed down through the centuries and was revered as the authoritative source for celestial information. While the Almagest contained no celestial maps, it did contain a description of each of the ancient constellations based on the positions and brightness of the stars within each constellation.
Early planispheres and celestial globes were popular, and it was only a matter of time until a true celestial atlas was to appear on the cartographic scene.
The year was 1540, and the place was Venice. Italian cardinal Alessandro Piccolomini was a prolific writer who turned his attention to the production of a book about the constellations and their mythical lore. He included woodcut maps of all but one of Ptolemy’s constellations – the stars of the constellation Equuleus were too faint to be represented. On his maps Piccolomini indicated stellar magnitudes and a scale for each constellation. However, he chose to omit drawings of the constellation figures themselves. In addition, his star charts lacked any coordinate system so there was no way to accurately determine the positions of stars in the sky.
The first celestial atlas with an accurate coordinate system and constellation figures did not appear until 1588. In that year, Giovanni Gallucci published an atlas of 48 woodcut constellation charts. In addition, his atlas included nebulae – a generic term for faint milky or cloudy objects in the sky. Ptolemy had identified seven such objects in the Almagest, and Gallucci included all of these.
Nebulae first appeared on planispheres about 1540. It was about that time, too, that certain new or modern constellations began to appear. Once the ancient constellations were placed on a celestial map or globe, vacant areas became evident. Map and globe makers began to invent new constellations to add to these vacant areas.
Gallucci’s atlas was a major advance, but it was to be overshadowed in 1603 by the first of the great celestial atlases.
Imagines Constellationum Borealium
Imagines Constellationum Australium
Northern and Southern Woodcut Celestial Planispheres
These early planispheres are typical of the first accurate celestial maps. They are divided at the ecliptic – the path that the sun and planets follow through the sky. The ecliptic is also the home of the zodiac. The twelve constellations of the zodiac lie along the ecliptic and the position of the sun within a constellation is the origin of the signs of astrology. The constellations of the zodiac appear along the edge of both maps.
The constellations on these planispheres are drawn from a geocentric viewpoint – in other words, the stars appear in the sky as they do when we look up at the heavens. Many early charts and atlases were drawn with an “external” or reverse-geocentric view like celestial globes. When we look “down” at the surface of a celestial globe, star patterns appear reversed because we are viewing them from outside the celestial sphere.
The primary coordinate system on these charts is ecliptical, but a secondary, equatorial coordinate system is also shown for the first time on these charts. The equatorial coordinate system (based on the equator of the Earth) would gain favor in the 18th century due to it’s superiority for determining positions in the sky. Today, equatorial coordinates are used almost exclusively.
No nebulae or modern constellations appear on these charts. Note that there are large, vacant areas in both the north and the south. The entire area around the south equatorial pole is vacant of constellations because this area was not visible from the Mediterranean or Middle East – the area where the ancient astronomers who invented the constellations documented in Ptolemy’s Almagest lived.
These particular charts were printed from woodcuts that were probably made about 1532. Printed charts from these woodcuts first appeared in a book published in 1541, but these particular examples are probably from one of the many reprints of this book that were published over the next 30 to 40 years.
The first true star atlas was published in Venice in 1540 as part of a volume on the myths of the constellations. The atlas consisted of individual charts of 47 of the 48 Ptolemaic constellations. Stars were displayed geocentrically (as seen from the Earth) with four magnitudes. One constellation was omitted – Equuleus contains no bright stars, so its chart would have been blank!
The author, Alessandro Piccolomini, was a prolific writer with works on many subjects, but he is best known for his star atlas which he wrote while a student at Padua.
Piccolomini opted to just show star patterns in his atlas. Constellation figures were not drawn on the maps. In addition, his star charts lacked any coordinate system so there was no way to accurately determine the positions of stars in the sky or even the orientation of each constellation with regard to its neighbors. Each chart simply showed the direction to the equatorial pole and a scale in degrees which differed for each chart. No nebulae or modern constellations were included.
This atlas proved to be immensely popular. The original was published in Italian, but at least ten Italian, three French and three Latin editions are known with the final edition appearing in 1595. The original charts were woodcuts and these were used for the first three editions, but other publishers did not have access to the original woodcuts. Two later editions used typeset star charts, but the rest of the later editions used new woodcuts which were not as accurate as the originals.
The atlas on display is a second edition published in 1548. It is opened to the constellations Cetus and Orion.
Giovanni Gallucci’s Theatrum Mundi, et Temporis is an encyclopedic work covering the motions of the planets, the nature of eclipses, and calculations of precession – the path that the Earth’s poles trace through the sky over a period of 26,000 years as the Earth’s axis wobbles like a top.
Theatrum Mundi also contains the first star atlas with an accurate coordinate system. Gallucci provides tables of star positions to magnitude 6 based on ecliptical coordinates derived from the star catalog published by Nicholai Copernicus in 1543. The atlas contains a woodcut star chart for each of the 48 Ptolemaic constellations, along with a table of star positions for each constellation given in degrees of latitude and longitude along with the magnitude of each star. The view is “external” or reverse-geocentric – the stars are shown reversed from how they actually appear in the sky.
Gallucci included drawings of the constellation figures, a trend that predominated well into the 19th century. In addition, his atlas included nebulae – a generic term for faint, cloudy objects in the sky. Ptolemy had identified seven such objects in the Almagest, and Gallucci included all of these. Few nebulae would appear in star atlases until late in the 18th century.
We know today that the nebulae depicted in early atlases represented a variety of objects ranging from clouds of interstellar gas to clusters of faint stars and even to galaxies far beyond the Milky Way. Unfortunately, the telescope was not invented until about 1607, and several of Ptolemy’s nebulae were nothing more than chance alignments of faint stars that appeared cloudy to the naked eye. Some nebulae on early atlases even appear to be imaginary – no objects can be found at these positions today. These “false” nebulae were sometimes perpetuated from atlas to atlas as each author copied his predecessors.
Gallucci included the first new constellation in his atlas but didn’t give it a chart of its own. Antinous, which had been introduced by the globe maker Casper Vopel in 1536, appears below the figure Aquila. Many new constellations would be introduced over the next two and a half centuries, and many of these remain in use today, but although Antinous was the first new constellation and was popular into the 20th century, it is no longer a recognized constellation.
The atlas on display is a first edition of 1588. It is opened to the constellation Cancer. A nebula symbol can be seen on Cancer’s back. This is actually a “false” nebula representing a faint group of several stars.
17th Century: Art and Science on the Rise
Cartography made a huge leap toward the end of the 16th century with the advent of copper engraved plates for printing illustrations. Copper engravings provided several advantages over woodcuts. The artist could produce much finer details engraving copper and the plates were more durable than woodcuts. The result was a stunning improvement in the overall quality of maps, both terrestrial and celestial.
But cartographic improvements were not the only advances that affected celestial atlases. Newer and more accurate star catalogs became available, and with the invention of the telescope in 1607, astronomers had a new tool with which to explore the heavens. In addition, catalogs of stars in the southern skies not visible in the north began to be available. The results were revolutionary.
The 17th century would lead off with the first of the four great star atlases in 1603 and would close with the second in 1690. In between, there would be many advances in science and many discoveries based on telescopic observations by astronomers of the day.
The first of what are recognized as the four great star atlases was published by Johann Bayer in 1603. Uranometria was based on observations by Tycho Brahe whose star catalog began to circulate at the end of the 16th century. In Bayer’s Uranometria, the charts were larger, the constellation figures (still one to a page) were far more artistic, the stars were far more accurately placed and the grades of star brightness were more uniformly shown.
Uranometria was the model for atlases of the 17th century. The overall format and content of atlases would not significantly advance until the 18th century.
Great artistic astronomical works also began to appear. These often included planispheres of the heavens along with charts that depicted various solar system theories, but the scale of planispheres was not sufficient to show off increased science except rudimentarily.
Although telescopes advanced quite a bit during the 17th century, they contributed relatively little to the overall science – and nothing to the art – of celestial atlases of that century. However, this century also marks the beginning of lunar cartography, and here telescopes had a profound influence. The first Moon atlas appeared in 1647 and this monumental work was not eclipsed until the 19th century.
Andromeda Auriga Argo Navis
Johann Bayer’s Uranometria, the first of the four great star atlases, represented a revolution in celestial cartography. Published in 1603, it was the first celestial atlas printed from copper-engraved plates. Copper engraving allows for much finer details than woodcuts. This permitted Bayer to portray the sky with much greater accuracy and precision.
In addition, Bayer had access to the new star catalog produced by Tycho Brahe and the first accurate observations of the southern sky by the Dutch navigator Pietr Dirksz Keyser. These provided Bayer with more modern and accurate star positions and magnitudes.
Bayer included one chart for each of the 48 Ptolemaic constellations and one chart of the southern sky with the twelve new constellations by Keyser. These charts were about four times the size of those by Piccolomini and Gallucci and had an accurate ecliptical coordinate system. The charts were oriented geocentrically to display the sky as it appears from the surface of the Earth.
Uranometria’s constellation figures were quite artistic compared with the planisphere’s and atlases that preceded it. In addition to displaying twice the number of stars, Bayer also displayed a shadowy outline of the Milky Way and a small number of real and false nebulae. The ecliptic coordinate system was overlaid with basic equatorial coordinate lines and the ecliptic – the path followed by the Sun and planets through the sky – was heavily emphasized as a broad, dark band across the charts that displayed it.
Uranometria was immensely popular, and numerous editions were published throughout the 17th century. The charts displayed here include Andromeda with the Milky Way crossing the lower left corner through the stars of Cassiopeia, Auriga which displays both the Milky Way from upper right to lower left and the ecliptic as a dark band across the bottom, and Argo Navis which also displays the Milky Way. Elsewhere in this exhibit, Bayer’s charts of Cygnus, Lyra and Cepheus are used for comparison with charts by later celestial cartographers.
St. Andrew (Taurus) The Sepulcher of Christ (Andromeda)
An interesting and beautiful celestial atlas, Coelum Stellatum Christianum, appeared in 1627. This atlas by Julius Schiller was essentially a revision of Bayer’s Uranometria. Schiller was a cartographer, not an astronomer, and he consulted with Bayer to update the astronomical content of the atlas.
Schiller’s charts included some improvements derived from the recent invention of the telescope and is arguably more accurate and detailed than Bayer’s Uranometria. Schiller preferred an external view of the sky, but otherwise, his charts were close in size and content to Bayer’s.
Where Schiller deviated from Bayer and almost all who preceded him was in his portrayal of the constellations. He chose to completely redefine and replace the traditional constellations with biblical ones. Schiller used figures from the New Testament for the northern hemisphere and figures from the Old Testament for the southern hemisphere. Where the twelve constellations of the Zodiac once separated the hemispheres, Schiller redefined these as the twelve apostles. This biblical view of the heavens was not popular and quickly relegated Schiller’s atlas to obscurity.
Schiller’s engravings are arguably the most artistic of any celestial atlas. Notice the detail in St. Andrew’s hands and face. Also note the cluster of stars in St. Andrew’s cape just above his right shoulder. This cluster in the constellation Taurus is known as the Pleiades or Seven Sisters. It is charted here including twelve stars, six of which are only visible with a telescopic. This was the most detailed view of the Pleiades to appear in any atlas until 1782.
Schiller replaced Andromeda with The Sepulcher of Christ. This constellation included a new nebula now known as the Andromeda Galaxy. Schiller included this and another nebula in Cygnus based on the naked-eye observations of the 10th century Arabic astronomer Al-Sufi.
Cruci Christi (Cygnus) Cygnus
Compare Bayer’s chart of Cygnus with Schiller’s chart of the same constellation, St. Helena and The Cross of Christ. Note that the stars are positioned as mirror images because Uranometria portrayed the stars geocentrically while Coelum Stellatum Christianum used an external view. The Milky Way appears as a faint diagonal band on both charts.
The second of the four great celestial atlases was published posthumously by the widow of Johannes Hevelius in 1690. Like Bayer’s Uranometria, Firmamentum Sobiescianum featured one constellation per chart with ecliptical coordinates and an equatorial coordinate overlay. However, like Schiller, Hevelius preferred the external or reverse-geocentric view, so his stars appear reversed compared with Bayer’s.
Although the telescope had now been around for eight decades, Hevelius didn’t trust telescopes for accurate star positions. He preferred to use his own naked eye observations of the night sky. Consequently, these charts are on about the same scale as Uranometria and contain about the same number of stars. Although Hevelius centered each chart on a different constellation, unlike Bayer, he included neighboring constellation figures. These were drawn with a lighter touch than the central constellation.
Hevelius drew the outline of the Milky Way but didn’t shade it like Bayer did. He also included a few new nebulae and corrected several false nebulae, but there were still only a small number of these shown.
Where Hevelius excelled was in his charts of the southern sky. Instead of a single chart, Hevelius showed the southern sky on several additional charts covering smaller areas similar to his northern charts. In addition, Hevelius had available the detailed survey and catalog of the southern sky produced by the young Edmund Halley in 1678. The result was the first portrayal of the southern sky with accuracy and detail equal to that of the northern sky.
Hevelius also introduced nine new constellations into the northern sky and displayed several other non-classical constellations that had been invented by others earlier. New constellations had begun to appear on planispheres, globes and atlases the century before. Cartographers invented them to fill empty areas of the sky where “unformed” stars appeared to exist outside the classical constellations. Some of these modern constellations gained favor and were carried forward by other cartographers, but many failed to earn a lasting place in the heavens. Seven of the nine constellations invented by Hevelius have survived to modern times: Canes Venatici, Lacerta, Leo Minor, Lynx, Scutum, Sextans and Vulpecula.
Hevelius named the features visible on the surface of the Moon after features on the Earth. There was an early theory that the surface of the Moon mirrored the surface of the Earth. Hevelius was aware of schemes to name the Moon’s features after men, but he feared slighting some at the expense of others and so he named mountain ranges, seas and craters for their equivalent features in and around the Mediterranean Sea on Earth.
Four years later, in 1651, Giovanni Battista Riccioli published a comprehensive work on astronomy entitled Almagestum Novum. Almagestum Novum included two charts of the Moon with and without features labeled. Rather than accept the nomenclature proposed by Hevelius, Riccioli returned to the idea of honoring famous men and named more than two hundred forty craters after modern and ancient men with associations to the field of astronomy. He also renamed the seas and mountain ranges without reference to features of the Earth. Instead, these were given names related to terrestrial weather.
Riccioli was particularly kind to celestial cartographers. He named features for Piccolomini, Bayer, Schiller, and Hevelius, as well as for himself!
History has been kind to Hevelius, but kinder to Riccioli. Only four of the names used by Hevelius for mountainous lunar features are still used, whereas nearly all of the lunar crater names proposed by Riccioli are still in use today, and his nomenclature system has been extended for naming additional smaller craters and features on the side of the Moon that faces the Earth.
Vincent Coronelli was a 17th century master cartographer. He produced terrestrial atlases and globes but also expanded his works to include celestial planispheres in his terrestrial atlases and celestial globes to compliment his terrestrial ones.
Coronelli was, in fact, most famous for his large globes. In 1681 he produced a pair of terrestrial and celestial globes four meters in diameter for King Louis XIV of France. This was the largest celestial globe ever made. But he also produced large globes on a commercial basis. These were just over a meter in diameter (42.5 inches). Such large globes would have been expensive to construct and difficult to transport, so Coronelli sold the individual gores by subscription, expecting the customer to have the finished globe constructed by a local globemaker. This proved to be an excellent marketing technique. The complete celestial globe consisted of twenty four half gores and two polar calottes.
John Flamsteed’s Atlas Coelestis, published in 1729, ushered in a new era of celestial cartography. The superior equatorial coordinate system we use today now took prominence. For the first time, an atlas displayed numerous stars discovered telescopically. This increased the number of stars for a given area of sky by about a factor of three. In addition to more stars and a better coordinate system, Flamsteed charted larger, overlapping areas of sky covering several constellations at once.
Flamsteed’s large atlas was copied at a much smaller scale by many others. There was still a great deal of variety in published charts and atlases during this century, but Flamsteed’s influence was clear.
l 1776: J. Fortin published a small French “Second Edition” of Flamsteed’s atlas. It was nearly identical, but much smaller with some additional new constellations, stars, and about 15 nebulae. Unlike Flamsteed, Fortin displayed the Milky Way.
l 1782: Johann Elert Bode published an atlas based on the French “Second Edition” of Flamsteed’s atlas. It was nearly identical, but with about 50% more stars and additional new constellations. It identified about 75 nebulae, but nearly half of these were false nebulae – no objects can be found at these coordinates today. This atlas contained some wonderful closeup drawings of nebulae, clusters and double stars making it the first atlas featuring such non-stellar objects.
l 1795: Joseph Jerome De Lalande and Pierre Francois Andre Mechain updated Fortin’s atlas of 1776 in their French “Third Edition” of Flamsteed’s atlas. Continuing the trend, they added a few additional constellations, many faint stars, and many more nebulae – nearly 100 in all including most of those in a famous list of bright non-stellar objects published by Charles Messier in 1781.
l 1799: Christian Goldbach published an atlas with white stars on a black background. It was virtually the same as the 1795 French “Third Edition” of Flamsteed’s atlas except for the reversed colors and the fact that Goldbach included two versions of each chart – one with constellation figures and one without. This was also the first atlas to systematically identify double stars.
l 1804: A Portuguese version of the 1795 French “Third Edition” was published.
l 1805: Bode updated and reissued his atlas of 1782 including many new constellations, stars and nebulae.
l 1819: Goldbach’s atlas of white stars on a black background was reissued.
l 1822: Alexander Jamieson published the last variation of Flamsteed’s atlas. Unlike its predecessors, the constellations were often hand-colored at the time they were produced.
John Flamsteed was England’s first Astronomer Royal. His life work involved compiling the first telescopic catalog of stars including positions and magnitudes for stars visible from Greenwich, England. Preparation of his celestial atlas began in 1715, four years before his death, but his atlas, the third of the four great celestial atlases, was not completed and published until 1729, ten years after his death.
Atlas Coelestis was a monumental work, displaying the heavens visible from Greenwich on twenty five charts. Each chart was about four times the size of Bayer’s charts and, with the aid of Flamsteed’s telescope, contained about three times the number of stars. Unlike his predecessors, Flamsteed relegated the ecliptical coordinate system to an overlay, using the superior equatorial coordinate system as the foundation for his charts which were highly accurate. He chose the geocentric view that had been favored by Bayer but abandoned by Schiller and Hevelius.
Flamsteed’s catalog of stars was intended as an aid to navigation. Therefore, it is not entirely surprising that no nebulae appear in his atlas since, by their nature, nebulae are distended objects that do not have precise coordinates like stars. Likewise, Flamsteed omitted the Milky Way whose boundaries are vague and represent a gradual increase in the background glow of billions of faint stars whose individual positions were beyond the scope of his atlas.
It might be a surprise then that Flamsteed included constellation figures on his charts. But rather than center each chart on one classical constellation, Flamsteed held each chart at approximately the same scale, centered on specific points of the celestial sphere with enough overlap to ensure coverage of the sky. Flamsteed’s atlas included only the portions of the celestial sphere visible from Greenwich – no detailed charts of the area around the southern celestial pole were included. By including most of the new constellations proposed by Hevelius, Flamsteed probably did more to ensure that these carried forward to modern times than Hevelius himself.
Flamsteed’s atlas proved to very influential. No less than eight small versions of his atlas were published by others across Europe over the next century, perpetuating the same chart layouts and associations of constellations. The chart displayed here is centered on Cancer but includes all or parts of many surrounding constellations.
1822 1795 1819
Flamsteed’s Atlas Coelestis was republished in England in 1753 and 1781, but no less than eight smaller versions were printed across Europe during the century after it first appeared. Shown is the area including Sagittarius on a sampling of smaller atlases modeled after Flamsteed’s Atlas Coelestis:
l 1782 – Bode’s German edition (reproduction)
l 1795 – The French “Third Edition”
l 1805 – Bode’s second German edition
l 1819 – Goldbach’s second German edition
l 1822 – Jamieson’s English edition.
Compare these with the full size original of Sagittarius from the 1729 edition of Atlas Coelestis. Despite their much smaller size (about one ninth the area of Flamsteed’s originals), these smaller atlases continued the trend toward greater science that started centuries earlier. More and more faint stars were included, along with many newly discovered nebulae and double stars. These atlases also included many new constellations, eventually crowding the heavens. Most of these newcomers were not retained when the constellations and their borders were finally set down permanently and unambiguously in 1930 by the International Astronomical Union.
The great celestial atlases were not the only atlases produced. Several significant works were produced in the 17th and 18th centuries that included numerous charts comparing various solar system theories by Ptolemy, Copernicus and Tycho Brahe as well as other solar system phenomena. These often included planispheres and sometimes simple celestial atlases.
Ignace-Gaston Pardies produced an interesting set of charts in 1673. Instead of centering each chart on a constellation as Piccolomini, Galluci, Bayer, Schiller and Hevelius had done, he simply imagined the Earth surrounded by a celestial “cube” and produced six charts – one for each face of this cube. Two of the sides represented the sky around the northern and southern equatorial poles. The other four sides were centered on the equator and divided into the four seasons based on the Summer and Winter solstices and the Vernal and Autumnal equinoxes.
Johann Doppelmayr produced a similar set of charts which he published as part of his Atlas Coelestis. His atlas also included two sets of planispheres, one set centered on the ecliptical poles and a second set centered on the equatorial poles. The latter appear here. Note that the copper plates were probably engraved about 1720, but knowing how long it took to publish such works in the 18th century, the stars were depicted with their equatorial coordinates for the year 1730. Doppelmayr included tables to calculate the precession of the Earth’s poles so that the actual positions could be determined for any given year within a few years before or after 1730. This was fortuitous since his atlas didn’t actually get published until 1741.
A small atlas of 54 copper-engraved charts was produced by Corbinianus Thomas in 1730. These small charts were centered on individual constellations and paled in scope compared to those of Flamsteed published the year before.
19th Century: A Quick Apex Followed by Descent
The 19th century started off with the last of the four great celestial atlases. In 1801, Johann Elert Bode published the most spectacular atlas of its kind. The charts somewhat resembled Flamsteed’s but were larger than in any previous star atlas and crowded with content. Bode increased the number of stars by another factor of six to more than 17,000 and identified hundreds of double stars. In addition to Charles Messier’s 100 bright nebulae, Bode included all 2,500 nebulae discovered by William Herschel in the late 18th century.
After Bode’s atlas, the artistic and scientific content of celestial atlases split. Atlases for scientific work became more detailed, but without the beautiful artwork of the constellation figures. To meet the popular needs of the public, atlases were simplified, and the constellation figures were less ornate, sometimes only shadowy or missing altogether. The first American atlas, published by Elijah Burritt in 1835, was the last major work of its kind. Burritt displayed the sky on four seasonal charts plus two polar charts with prominent constellation figures, similar to what Pardies had done in 1674 and Doppelmayr in 1742, except that Burritt’s charts resembled globe gores and calottes as opposed to the six sides of a celestial cube used by Pardies and Doppelmayr. Burritt’s charts were excellent for novice sky watchers and students using their naked eyes, but essentially useless for serious astronomy. It was the last significant atlas to include prominent constellation figures.
Bode Flamsteed Bayer
The fourth and last of the great celestial atlases, Uranographia, was published in 1801 by Johann Elert Bode. Bode had published one of the small versions of Flamsteed’s atlas in 1782, but Uranographia represented a whole new level of science.
Like Flamsteed, Bode only provided charts for the portion of the sky visible from central Europe, and like Flamsteed, Bode used equatorial coordinates and constellation figures. But Bode’s charts were physically twice the area of Flamsteed’s charts and were absolutely crowded with content in comparison. Bode covered the heavens in only 18 charts compared with Flamsteed’s 25, but on those charts he included 17,000 stars – six times as many as Flamsteed. He also included numerous new constellations, many of them invented by Bode just for Uranographia.
Unlike Flamsteed, Bode included nebulae – lots of them! In addition to the list of 100 published by Charles Messier in 1781, Bode included the 2,500 nebulae cataloged by William Herschel in the late 18th century. He also restored the Milky Way and systematically identified hundreds of stars with a symbol indicating that they were telescopic doubles.
The chart from Uranographia on display here covers the northern polar area. Aside from the fact that it appears inverted from Flamsteed’s chart of the northern polar area, note that it covers a somewhat different area – the borders are not in the same star fields. Bayer’s chart of Cepheus – a central figure on the charts by Bode and Flamsteed, is also provided for comparison.
The advances from Bayer (1603) to Flamsteed (1729) are obvious, but a close examination of Bode’s chart (1801) shows that the advances in content are even greater for this last of the great celestial atlases. Here is an atlas that today’s amateur astronomer with a modern telescope could happily use for many years of heavenly exploration.
The first celestial atlas published in the United States was actually the last significant atlas to include prominent constellation figures. After this, constellation figures, if they appeared at all, were typically only shadowy figures among the stars of the heavens.
Elijah Burritt published his atlas for use by educators in America. It was very popular and was republished several times to meet demand.
Burritt’s celestial charts were a little like those of Pardies and Doppelmayr. There were circular charts for the northern and southern equatorial poles, and seasonal charts for the equatorial areas. But rather than distort the heavens with square charts, Burritt tapered his seasonal charts as if they were globe gores with polar calottes.
As became typical in the 19th century, Burritt’s charts were covered with nearly every constellation ever imagined by his predecessors, but the scale of these charts permitted only the brightest stars to be displayed and little if any scientific information was presented besides the rough positions and brightness of these stars.
Most charts and atlases published prior to 1820 were sold uncolored. Color was sometimes added later, but not usually by the original publisher. Burritt’s charts were an exception. Like the Jamieson atlas of 1822, these charts were hand colored with simple pastel washes at the time they were published.
20th Century: The Modern Era
Where the 19th century started off with the amazing Uranographia by Bode in 1801, it was a century and a half before modern star atlases were produced for the amateur astronomer that could be considered an improvement.
For all intents and purposes, the modern era of celestial atlases was ushered in by Anton Becvar with his Atlas Coeli 1950.0 published in 1948 with star positions calculated for January 1, 1950. This atlas provided sixteen charts covering the entire sky. Not only did it include all stars to magnitude 7.75, but it also included thousands of deep sky objects and, unlike earlier atlases that usually used a single symbol to identify nebulae, it differentiated these by using different symbols to indicate what type of object each was. As expected for a modern scientific atlas, constellation figures were no longer included. But the boundaries for constellations were clearly identified.
This atlas became the prototype for all modern star atlases. Becvar’s symbols for deep sky objects have been used consistently by all subsequent authors. While advances have come rapidly, all modern atlases are evolutionary rather than revolutionary. They all are recognizable as having their roots in Becvar’s Atlas Coeli 1950.0.
l 1958 – Becvar issued a color version of Atlas Coeli 1950.0 entitled Atlas of the Heavens.
l 1981 – Wil Tirion published Sky Atlas 2000.0 with the first computer generated charts. All future atlases will have computer generated charts. Sky Atlas 2000.0 includes 26 charts with 43,000 stars and 2500 non-stellar objects.
l 1987 – Wil Tirion, Barry Rappaport and George Lovi published Uranometria 2000.0 including 473 charts with more than 332,000 stars and 10,300 non-stellar objects.
l 1997 – Roger Sinnott and Michael Perryman published Millennium Star Atlas including 1,548 charts with more than a million stars and more than 10,600 non-stellar objects.
The information available now has exceeded that which can be reasonably portrayed in a printed atlas. Therefore, the most detailed charts are those that are available as computer software. Recent examples currently include more than 15 million stars.