Fixed star:  COPULA
Constellation:   M51 Canes Venatici
Longitude 1900:  23VIR43 Longitude 2000:  25VIR08
Declination 1900:  +47.43' Declination 2000:  +47.12'
Right ascension:  13h 29m Latitude:  +50.55'
Spectral class:  N Magnitude: 8.1 is the brightest star

The history of Copula

from p.116 of Star Names, Richard Hinckley Allen, 1889.
[A scanned copy can be viewed on this webpage]

Canes VenaticiM51 Canes Venatici, Copula, is the Spiral Nebula, or the Whirlpool Nebula, N.G.C. 5194, 51 M. in the northern of the two greyhounds of the constellation Canes Venatici.

Asterion is the name of the northern hound, and Chara is the southern hound. The northern hound is named Asterion from the little stars marking the body and because it contains the M51 Whirlpool Nebula.

Described in 1899 as "a misty spot which appears to {p. 117} be composed of a pair of curving arms issuing from opposite extremities of an oval central body, one of the arms joining itself to a second nucleus, — a new star system in process of formation".

[Star Names, Their Lore and Meaning, Richard Hinckley Allen, 1889].


The Spiral or Whirlpool Nebula mentioned by Ptolemy as the nebula under the tail of the Great Bear. [Robson*, p.157.]


The word 'copula' means 'a linking verb', or anything that provides a link between two things. From Indo-European word ap-1 To take, reach. Derivatives are copulate, couple, from Latin copula, bond, tie, link, bond, pair. [Pokorny 1. ap- 50].

The astrological influences of the constellation Canes Venatici

This constellation gives a love of hunting and a penetrating mind, making those born under it faithful, keen, clever and fond of speculation. [Robson*, p.34.]

The astrological influences of the star Copula or the Nebula M51

It is of the nature of the Moon and Venus, and causes blindness (all nebula have this effect), defective eyesight, strong passions, hindrances and disappointments. [Robson*, p.157.]


*[Fixed Stars and Constellations in Astrology, Vivian E. Robson, 1923].