Johannes Hevelius (1611–1687) was a Polish astronomer, born at Gdańsk in a wealthy family of brewers. As a young man, he visited several countries of Europe. Back in Gdańsk, he dedicated himself to business and public affairs. Starting in 1639, he turned most of his attention to astronomy under the advice of his former professor Peter Crüger, while remaining involved in the public affairs of the city until the end of his life.

Johannes Hevelius

Johannes Hevelius

He conducted his observations from an observatory built on the roof of his house, made his own telescopes, had a printing press in his house, and drew and engraved many of the plates used to illustrate his books. He suffered a major setback in 1679 when his house, observatory, and library were destroyed by fire, but he rebuilt and continued his work.

Hevelius discovered the libration of the moon, charted the moon's surface, observed sunspots, and discovered four comets. He published several astronomy books. His last work, Prodromus Astronomiæ [5], was published posthumously by his second wife and collaborator Elisabeth Koopman in 1690. It contains a star catalog of 1564 entries entitled Catalogus Stellarum Fixarum (pp. 143–268) and a celestial atlas Firmamentum Sobiescianum. The atlas features 10 new constellations described in the next section.

The telescope was in its infancy at the time, but Hevelius preferred to conduct his measurements of star positions with plain sights. This triggered a controversy with Robert Hooke, secretary of the Royal Society of which Hevelius was a fellow, who dispatched Edmond Halley to Gdańsk in 1679. Halley validated Hevelius's methods.

More biographical details can be found in Baily [2] in the introduction to Hevelius's catalog. This page focuses on the star catalog from Prodromus. This catalog came after Tycho Brahe's and attempted to improve on it, but was overshadowed by Flamsteed's only a few decades later. Still, it contains many stars not included in Flamsteed's catalog and has regularly been referred to by later astronomers.

Hevelius's catalog has already been put in machine-readable form by F. Verbunt and R. H. van Gent [1] and made available as VizieR's catalog J/A+A/516/A29.

I digitized it independently anyway in order to capture the original catalog's columns omitted in VizieR, which contain the stars' equatorial coordinates computed from the ecliptic ones, as well as the ecliptic coordinates according to the catalogs of Tycho Brahe, William IV Landgrave of Hesse-Cassel, Giovanni Battista Riccioli, Ulugh Beg and Ptolemy, precessed to Hevelius's catalog equinox (1661).

I also included Baily's reprint of Hevelius's catalog in [2] and Flamsteed's version from Historia Cœlestis [4]. Flamsteed's version has been the one in most general use, but it orders the stars differently and I wanted to capture the mapping between versions.

Constellations in Hevelius's catalog

Hevelius's catalog groups stars by constellation. Only 43 of the 48 Ptolemaic constellations are represented: the southernmost (Ara, Centaurus, Corona Australis, Lupus, and Piscis Austrinus) are omitted. Only the northern parts of Eridanus and Navis are populated.

Hevelius includes the newer constellations Antinous and Coma Berenices introduced by Caspar Vopel in 1536 and already adopted by Tycho Brahe in his catalog. He also includes the constellations Camelopardalis and Monoceros introduced by Petrus Plancius on a globe in 1612.

In addition, the catalog and atlas feature 9 new constellations:

Hevelius's NameModern Name
Canes Venatici, Asterion & CharaCanes Venatici
Lacerta sive StellioLacerta
Leo MinorLeo Minor
Lynx sive TigrisLynx
Scutum SobiescianumScutum
Sextans UraniæSextans
Triangulum Minus
Vulpecula cum AnsereVulpecula

of which two are now obsolete (Cerberus and Triangulum Minus, reabsorbed into Hercules and Triangulum) but the other seven have remained in use and are now part of the official 88. The atlas also features the obsolete constellation Mons Menalis at the foot of Boötes.

In the catalog, the constellations are generally enumerated in alphabetical order of their Latin names, considering the letters U and V as identical (the Ursæ come after Virgo). Camelopardalis is a little out of place, which Baily has corrected. Canes Venatici appears after Canis Major and Canis Minor as if the plural "Canes" were considered equivalent to "Canis" in the alphabetical order.

Catalog data

The following files cover the different versions of the catalog.

File name Explanation
ReadMe File descriptions
hevelius.dat Hevelius's full catalog according to Prodromus
hevelius_h.dat Hevelius's simplified catalog according to Prodromus
hevelius_b.dat Hevelius's catalog according to Baily
hevelius_z.dat Hevelius's catalog according to Flamsteed
notes.dat Notes on Hevelius's catalog
notes_b.dat Notes on Baily's version of Hevelius's catalog
notes_z.dat Notes on Flamsteed's version of Hevelius's catalog
notes_eq.dat Notes on equatorial coordinates

The ReadMe file describes the file formats, following the conventions for catalog descriptions of the VizieR service.

The file hevelius.dat contains the full Hevelius catalog. The original uses two lines to represent each catalog entry. The first line contains the description, Tycho number and magnitude, Hevelius magnitude, longitudes, and right ascension; the second line the latitudes and declination. The file presents each entry on a single "unfolded" line for convenience.

The files hevelius_h.dat, hevelius_b.dat, and hevelius_z.dat contain the catalog versions according to Hevelius (a selection of columns from hevelius.dat), Baily, and Flamsteed. For easy comparison, their layouts are compatible, although Flamsteed uses polar distance rather than declination and the magnitude representations differ. The ecliptic coordinates precede the equatorial ones in the files, although they follow them in the original Flamsteed version.

Hevelius's numbering occupies the first three columns. The next three columns give Baily's numbering in Baily's version, when it differs from Hevelius's, and Flamsteed's numbering in Flamsteed's version.

The notes files collect observations about the respective versions such as the particular format of magnitude values, typos and errors that I detected, discrepancies between versions, etc.

There are several computation errors in Hevelius's equatorial coordinates, some of which were fixed by Baily or Flamsteed. I have recomputed all equatorial coordinates (with the unfair assistance of an electronic computer) and compared them with Hevelius's values in notes_eq.dat. I used the value 23°30'20" for the obliquity of the ecliptic, according to Baily [2, p. 47].

Flamsteed's version

Hevelius's catalog is reprinted in John Flamsteed's Historia Cœlestis Britannica [4], but in a different form. Flamsteed reordered the constellations and, within each constellation, reordered the stars by right ascension, west to east (with 3 exceptions documented in notes_z.dat).

Flamsteed's version merges the constellations Triangulum Minus and Triangulum into Triangula (the Triangles). It omits the 18 catalog entries for which Hevelius has not given coordinates of his own, as well as 2 duplicate entries in Perseus (Per 47 and Per 48) that would be conspicuous in a list sorted by constellation and right ascension. For no apparent reason, the constellations Corvus (8 stars) and Leo Minor (18 stars) are omitted entirely, and so is a single star in Sextans (Sex 4). Flamsteed's version ends up with 1517 catalog entries instead of 1546, to which I have assigned a global sequence number and a sequence number within the constellation.

As Baily mentions [2, p. 47], references to Hevelius's catalog found in the work of later astronomers usually use Flamsteed's numbering. The file hevelius_z.dat includes the mapping between Hevelius's and Flamsteed's numberings.

Baily's version

Baily mentions and numbers the entries without Hevelius coordinates, but leaves the coordinates blank.

He rectifies the alphabetical order of the constellation names by placing Camelopardalis before Cancer. This only affects the global numbering of the stars from Camelopardalis to Canes Venatici.

He corrects the equatorial coordinates which he had "reason to suspect" [2, p. 47]. The file notes_eq.dat flags the ones that he or Flamsteed caught.

Star identifications

Baily assigns Bayer, Flamsteed, or Piazzi designations to Hevelius's stars and sometimes, in the notes, he gives a reference to Lalande's Histoire Céleste Française [3]. Flamsteed only identifies the stars by a letter from Bayer's atlas or from his own catalog.

I gathered these identifications in their raw form in the following files, described in the ReadMe file. The Bayer designations have continued to evolve after Flamsteed and Baily and should be interpreted in their respective contexts.

File name Explanation
cross_b.dat Star identifications according to Baily [2]
cross_z.dat Star identifications according Flamsteed [4]
dups.dat Duplicate entries

Duplicate entries

The file dups.dat, described in ReadMe, lists 13 pairs of probable duplicate entries found in the catalog. Each pair is repeated in reversed orders. The actual constellation of the pair and the distance (in arcminutes and based on the ecliptic coordinates) between the members are given next to one of the members. The maps show double labels for all pairs.

This list is compatible with the one given in Verbunt & van Gent [1]. Baily flags only 4 pairs of duplicates in his notes (see notes_b.dat) but his identifications are compatible with the full list of 13. Flamsteed omits two duplicate entries in Perseus but fails to catch any other legitimate pair of duplicates through his identifications.

Tycho numbers

The catalog gives Tycho numbers for many entries, in addition to precessed Tycho positions. Some of the Tycho numbers refer to another constellation than the one assigned by Hevelius. These cases are collected in the following list.

258Cnc 2Hya24
273Cnc17CMi 5
993Mon 1Ori58
994Mon 2Ori60
995Mon 3Ori57
996Mon 4Ori56
997Mon 5Ori59
998Mon 6Ori61
999Mon 7Ori62
1000Mon 8Ori53
1001Mon 9Ori55
1241Sco 7Lib17
1242Sco 8Lib16
1243Sco 9Lib12
1314Ser 9Oph16
1320Ser15Oph 9

Some of the Tycho numbers refer to Kepler's Secunda Classis catalog rather than Tycho's. They are collected in the list below, which agrees with the one given in Verbunt & van Gent [1] (caveat: my numbering of Kepler's Secunda Classis stars differs from Hevelius's in Sagittarius due to the different treatment of the multiple copies of γ2 Sgr and δ Sgr).



[1] F. Verbunt & R. H. van Gent, The star catalogue of Hevelius, Astronomy & Astrophysics 516, A29 (2010).

[2] Francis Baily, The Catalogues of Ptolemy, Ulugh Beigh, Tycho Brahe, Halley, Hevelius, Deduced from the Best Authorities. With Various Notes and Corrections, and a Preface to Each Catalogue. To Which is Added the Synonym of each Star, in the Catalogues of Flamsteed or Lacaille, as far as the same can be ascertained. Memoirs of the Royal Astronomical Society, Vol. 13, London, 1843. Also available here.

[3] Jérôme de Lalande, Histoire Céleste Française, Tome I, Imprimerie de la République, Paris, 1801.

[4] John Flamsteed, Historia Cœlestis Britannica, Tribus Voluminus contenta. Volumen Tertium, London, 1725.

[5] Johannes Hevelius, Prodromus Astronomiæ, Gdańsk: Johann Zacharias Stoll, 1690.


  • This research has made use of the VizieR catalogue access tool, CDS, Strasbourg, France. The original description of the VizieR service was published in A&AS 143, 23.
  • This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France.
  • Illustration: Joannes Hevelius [Hewelke]. Mezzotint by J. Faber after A. Stech, 1677. Credit: Wellcome Collection. CC BY