Flamsteed’s Atlas Coelestis
Celestial mapping took another major stride in the 18th century with the work of
the first Astronomer Royal of England, John Flamsteed, who catalogued nearly
3000 stars with unprecedented precision from the newly founded Royal
Observatory at Greenwich. Flamsteed’s star catalogue was published posthumously in 1725 in Volume 3 of his Historia Coelestis Britannica; the catalogue section itself was called Catalogus Britannicus. Four years later came Atlas Coelestis, a set of 25 elegantly engraved celestial charts based entirely on Flamsteed’s own observations. The far southern skies, below the horizon of Greenwich, are
covered by one small chart that depicts the 12 constellations of Keyser and de
Houtman plus Halley’s Robur Carolinum.
Flamsteed took particular care to depict the constellation figures exactly as
Ptolemy had described them. The introduction of Atlas Coelestis contains some disapproving words about the way that Bayer had represented the
constellation figures in his Uranometria:
“Having drawn all his human figures, except Boötes, Andromeda and Virgo, with their backs towards us, those stars, which all
before him place in the right shoulders, sides, hands, legs or feet, fall in
the left, and the contrary ... whereby he renders the oldest observations false
or nonsense.”
Despite popular misconception, Flamsteed did not introduce the so-called
Flamsteed number system for identifying the stars in each constellation; that
was done in 1783 by the Frenchman J. J. Lalande. In a French edition of Flamsteed’s catalogue Lalande inserted a column in which he numbered the stars consecutively in each
constellation in the order that Flamsteed had listed them, and this is the
system that astronomers mean when they speak of Flamsteed numbers. Stars are
usually referred to by their Flamsteed numbers – for example 61 Cygni or 70 Ophiuchi – only when they are not already identified by a Greek letter.
One legacy of Flamsteed’s atlas which is sometimes overlooked is the sequence of smaller popular atlases
that it inspired: Jean Fortin’s Atlas Céleste in France (1776 and 1795), Johann Bode’s Vorstellung der Gestirne in Germany (1782 and 1805), and Alexander Jamieson’s Celestial Atlas in England (1822), all of which in turn had their own imitators. See my page on
Old Star Atlases for more on this Flamsteed tradition.
Bode’s Uranographia
Flamsteed’s catalogue and atlas set new standards in astronomy, and I have used his atlas
as one of the sources for illustrations on these pages. The other main source
is the greatest of the old-style pictorial star atlases, Uranographia, published in 1801 by the German astronomer Johann Elert Bode, director of Berlin
Observatory. (It actually appeared in five parts from 1797 onwards, but 1801
was the completion date.)
Bode’s Uranographia was the first atlas to depict virtually all the stars visible to the naked eye
(i.e. down to sixth magnitude), plus a fair selection of those down to six
times fainter (eighth magnitude). Over 17,000 stars are plotted, taken from the
observations of various astronomers including Flamsteed, Lacaille, Lalande, and
Bode himself. To accompany the atlas, Bode produced a catalogue called Allgemeine Beschreibung und Nachweisung der Gestirne, also published in 1801.
Bode intended the Uranographia to be comprehensive and he certainly succeeded, for in addition to charting a
greater number of stars than any previous cartographer he also depicted more
constellations – over 100 of them (for a complete list see here). Among them were five constellations making their debut on this atlas: Felis and Globus Aerostaticus were both suggested by Lalande during the preparation of the atlas, while Lochium Funis, Machina Electrica, and Officina Typographica were invented by Bode himself. None of these five survived the test of time,
however.
Bode’s Uranographia marked the end of an era. Thereafter, astronomers placed decreasing emphasis on
the fanciful (and physically meaningless) constellation figures of the Greeks,
concentrating instead on the exact measurement of position, brightness, and
physical properties of the stars.
End of a tradition
In the transition from classical to scientific mapping one atlas stands out: the
Uranometria Nova of the German astronomer F. W. A. Argelander published in 1843. In this, the
constellation figures, printed in red, were reduced to shadowy insignificance
by comparison with the stars. This same two-colour style was followed by
Argelander’s countryman Eduard Heis in his Atlas Coelestis Novus of 1872. These atlases were the standard references for professional
astronomers of the day, and their choice of constellations helped establish the
eventual list of 88 adopted by the International Astronomical Union.
By the end of the 19th century, two thousand years of Greek tradition had
finally given way to the facts-and-figures approach of astronomical
census-takers and statisticians. Where the ancient Greeks imagined their gods
and heroes populating the sky, modern astronomers have discovered the existence
of an equally fantastic pantheon of objects with names such as red giants,
white dwarfs, Cepheid variables, pulsars, quasars, and black holes.
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© Ian Ridpath. All rights reserved
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