''Prodromus Astronomiae'' is a

star catalog A star catalogue is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the years, ...

created by

Johannes Hevelius Johannes Hevelius Some sources refer to Hevelius as Polish: * * * * * * * Some sources refer to Hevelius as German: * * * * *of the Royal Society * (in German also known as ''Hevel''; pl, Jan Heweliusz; – 28 January 1687) was a councillor ...

and published posthumously by his wife and research aid

Elisabeth Hevelius Elisabeth Catherina Koopmann-Hevelius (in Polish called ''Elżbieta Heweliusz''; January 17, 1647–December 22, 1693) is considered one of the first female astronomers. Originally from Danzig, Poland, she contributed to improve the work and obs ...

in 1690. The catalog consists of the location of 1,564 stars listed by constellation. It consists of three separate parts: a preface (labeled ''Prodromus''), a star catalog (named ''Catalogus Stellarum''), and an atlas of constellations (named ''Firmamentum Sobiescianum, sive Uranographia'').

''Prodromus''

''Prodromus'' outlines the methodology and technology used in creating the star catalogue. It provides examples of the use of the

sextant A sextant is a doubly reflecting navigation instrument that measures the angular distance between two visible objects. The primary use of a sextant is to measure the angle between an astronomical object and the horizon for the purposes of ce ...

and quadrant by Hevelius, in tandem with known positions of the sun, in calculating each stars' longitude and latitude.

''Catalogus Stellarum''

The written draft of the ''Catalogus Stellarum'' consists of 183 leaves, 145, alphabetized according to constellation, containing star positions. Each star had specific information recorded in columns: the reference number and

magnitude Magnitude may refer to: Mathematics *Euclidean vector, a quantity defined by both its magnitude and its direction *Magnitude (mathematics), the relative size of an object *Norm (mathematics), a term for the size or length of a vector *Order of ...

found by astronomer

Tycho Brahe Tycho Brahe ( ; born Tyge Ottesen Brahe; generally called Tycho (14 December 154624 October 1601) was a Danish astronomer, known for his comprehensive astronomical observations, generally considered to be the most accurate of his time. He was ...

, Hevelius' own magnitude calculation, the star's longitude and latitude by both ecliptic coordinates measured by angular distances and meridian altitudes found using Hevelius' quadrant, and the star's equatorial coordinates calculated using spherical trigonometry. The printed version was similar to the written draft, except the two columns describing a star's ecliptic coordinates were combined, and only the single best value for the star's latitude and longitude was given. Also, the printed version held more than 600 new stars and 12 new constellations not documented in the written draft, bringing its total to 1564. Although the observations of the catalog used nothing more than the astronomer's naked eye, the measurements were so precise as to be used in the making of celestial globes into the early 18th century.

''Firmamentum Sobiescianum''

''Firmamentum Sobiescianum'', while technically part of the ''Prodromus Astronomiae'', was likely published separately and in tighter circulation. Housing its own cover page and page-numbering system, the atlas consisted of two hemispheres and 54 double-page plates of 73 constellations. Both the northern and southern hemispheres were centered on an ecliptic pole, and most star locations were all based on Hevelius' own observations. Those that were not, the southern polar stars, were based on a catalog and map published in 1679 by

Edmond Halley Edmond (or Edmund) Halley (; – ) was an English astronomer, mathematician and physicist. He was the second Astronomer Royal in Britain, succeeding John Flamsteed in 1720. From an observatory he constructed on Saint Helena in 1676–77, H ...

References

{{Reflist Astronomical catalogues of stars