Quadrans Muralis

The radiant of the Quadrantids meteor shower displayed in Stellarium (2025) with stars only shown brighter than 6.5 mag. The star closest to the current radiant is marked.

This is one of the obsolete constellations from Early Modern Europe. The term is Latin and means "wall-mounted quadrant", a large astronomical instrument fixed to a wall. The constellation is still in common memory of meteor observers as a rich meteor shower that peaks in the first days of January are known as the Quadrantids. Their apparent point of origin, the radiant, is in the area where historically this constellation used to be defined.

Etymology and History

Quadrans Muralis in Fortin's 1795 star catalogue (first page).

Quadrans Muralis in Fortin's 1795 star catalogue (second page).

Origin of Constellation

The constellation was originally invented by the French astronomer Joseph Jérôme Lalande in 1795 which he explains in the Connaissance des temps in 1796.

Aux constellations déjà reçues j'ai ajouté le Mural ou quart de cercle mural, qui est gravé dans la nouvelle édition de l'atlas de Flamsteed que j'ai corrigée et augmentée en 1795. Ce Mural est dans un espace vide, entre le Dragon, le Bouvier et Hercule. La Caille après avoir observé les étoiles australes, forma 14 constellations nouvelles avec les instrumens de la physique et des arts; j' ai cru pouvoir, à son exemple, consacrer dans l'hémisphère boréal, I'instrument précieux qui a servi déjà aux observations de 32 mille étoiles, c'est-à-dire, au plus grand monument de I'astronomie; et je crois que les astronomes à venir, profitant de cet immense travaiI, conserveront volontiers une constellation faite pour en rappeler la mémoire.

English

To the known constellations, I have added Le Mural or The Quarter of a Wall Quadrant, which is engraved in the new edition of Flamsteed's atlas which I had corrected and expanded in 1795. This "Mural" is in a free space between the Dragon, the ... and Hercules. After observing the southern stars, La Caille formed 14 new constellations using the instruments of physics and the arts. Following his example, I thought I could dedicate [a space] in the northern hemisphere to the precious instrument that has already been used to observe 32,000 stars, in other words, the greatest monument of astronomy. Furthermore, I believe that the future astronomers taking advantage of this immense work, will be happy to preserve a constellation designed to serve as a reminder.

In his "Bibliographie astronomique, avec l'histoire de l'astronomie depuis 1781 jusqu'à 1802" he notes on page 633:

... et de plusieurs constellations nouvelles, entre autres le Mural, que j'ai placé dans le ciel pour conserver la mémoire de l'instrument précieux qui a servi à la détermination de 50000 étoiles. -- Connaissance des temps, 1796.

English

... and many new constellation, among them le Mural, that I have placed in the sky to preserve the memory on a high-precision instrument that has served to determin 50000 stars.

Depictions in Atlasses

In the same year, the French astronomer Jean Fortin published the 3rd edition of his Atlas céleste and a star catalogue in which he listed ten stars in the constellation "Le Mural" (in French).

Fortin's atlas started in 1776 as a French edition of Flamsteed's 1729 Atlas Coelestis written in English (maps labelled in Latin). This book (1st edition 1776; 2nd edition 1778) of the Atlas céleste does not show Quadrans, neither in the Bootes map nor in the Draco map. His 3rd edition, published in 1795 (with participation of others, e.g. Lalande) shows the new constellation Quadrans in the Draco map, but not in the map of Bootes.

The German astronomer Johann E. Bode had included a German edition of Flamsteed's atlas in his popular book Anleitung zur Kennntniß des gestirnten Himmels (1782). In the 2nd edition of this book in 1805, he depicted the new constellation Quadrans in the map of Bootes, but not in the map Draco (so he did not copy from Fortin directly). It is clearly visible that he had used the same copper plates for the print as in 1782 because he did not erase the boundary lines between the constellations that he had invented. (There are no boundaries drawn in Flamsteed or Fortin.) The image of the constellation Quadrans is at the place where the boundaries of the three constellations Bootes, Hercules and Draco meet.

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  Fortin's 1776 (1st edition) of the Atlas céleste without Quadrans (Dra).

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  Fortin's 1776 (1st edition) of the Atlas céleste without Quadrans (Boo).

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  Fortin's 1795 (3rd edition) of the Atlas céleste with Quadrans in the map of Draco.

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  Fortin's 1795 (3rd edition) of the Atlas céleste still without Quadrans in the map Bootes.

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  Goldbach's 1799 atlas with Quadrans between Draco, Hercules and Bootes.

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  Goldbach's 1799 atlas with Quadrans north of Bootes.

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  Bode's 1805 edition of his Bootes-star chart in Anleitung zur Kenntniß des gestirnten Himmels (labelling in German).

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  Bode's 1805 edition of Anleitung zur Kenntniß des gestirnten Himmels with the star chart of Draco still without Quadrans.

In his 1801 trilingual magnus opus Uranographia (with text in German and French, and constellation maps labelled in Latin), Bode took up the idea of this constellation and incorporated it in the map of Bootes. This map is not anymore based on Flamsteed's drawings, but a completely new celestial map with deviating shapes of constellations and many more objects (stars, star clusters and other nebulae) registered.

Alexander Jamieson and Sidney Hall in the subsequent decades also depicted Quadrans together with Bootes.

Transfer and Transformation of the Constellation

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  Bode 1801 Uranographia, Quadrans as a neighbouring detail next to Draco

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  Bode's (1801), Quadrans Muralis in Uranographia, Johann E. Bode. This file is from Wikimedia Commons and may be used by other projects

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  Quadrans in Alexander Jamieson (1822), Plate 7 from A Celestial Atlas comprising a systematic display of the heavens in a series of thirty maps illustrated by scientific description of their contents and accompanied by catalogues of the stars and astronomical exercises

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  Sidney Hall, Urania's Mirror (1825): "Bootes, Canes Venatici, Coma Berenices, and Quadrans Muralis", plate 10, a set of celestial cards accompanied by A familiar treatise on astronomy ... by Jehoshaphat Aspin. London. Astronomical chart, 1 print on layered paper board : etching, hand-colored.

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  Map of the ancient constellation Quadrans Muralis. Created by CWitte with PP3 (PP3's homepage) byTorsten Bronger. This file is from Wikimedia Commons and may be used by other projects.

Mythology

no mythology

IAU WGSN Name Discussion

In 2023 and 2025, it was suggested to use a name related to this obsolete historical constellation. The terms "Quadrans" or "Muralis" could be used to name a star in the area of this historical constellation; the first term makes more sense with regard to its reminiscence in the name of the meteor shower.

WGSN chose to ...

References

• References (general)
• References (Babylonian)
• References (ancient Greco-Roman)
• References (medieval)