Quadrans Muralis

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

Etymology and History

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Quadrans Muralis in Fortin's 1795 star catalogue (first page).
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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. [1]

In the same year, the other French astronomer Jean Fortin published the 3rd edition of his Atlas Céleste and a star catalogue in which he mentions 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).

Jean Fortin's 1776 (1st and 2nd edition) 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 other, e.g. Lalande) show 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. It is clearly visible that he had used the same copperplates for the print as in 1782 because he did not erase the boundary lines between the constellations that he had invented. (There were 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.

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.[2] 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

Mythology

no mythology

Weblinks

References

  1. Ian Ridpath, Star Tales, Lalande's Quadrans Muralis (Online Edition)
  2. Ian Ridpath, Star Tales, Quadrans Muralis (Online Edition)