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Proper NameWezen
Bayer DesignationDelta Canis Majoris
Flamsteed Number25 Canis Majoris
HR (BSC)2693
ConstellationCanis Major
Right Ascension7h 8m 23s
Declination-26° 23' 36"
Distancec.1,600 light years
c.500 parsecs
MagnitudeApparent: +1.8
Absolute: -6.6
Spectral ClassF8Ia bright yellow Supergiant
Optimum VisibilityJanuary
NotesA highly luminous supergiant star, Wezen emits about 40,000 times the light energy of the Sun. It is also immense in size, at some two hundred times the diameter of the Sun. If it lay in the centre of the Solar System, it would consume both Mercury and Venus and extend almost to the orbit of Earth.

The third brightest of the stars of Canis Major in the sky, after brilliant Sirius and Adhara, which lies close to Wezen on the fringes of the Milky Way. In fact Wezen is intrinsically much more luminous than either Sirius or Adhara, but it is also much further away from Earth at a distance of some 1,600 light years. If it were as close to the Solar System as Sirius, it would shine more brightly than Venus in the skies of Earth.

Wezen is a supergiant star of the bright yellow 'F' spectral classification, some two hundred times the diameter of the Sun, and generating more than three thousand times as much light. In common with other such massive and luminous stars, Wezen's lifespan is a short one. Only ten million years old (a tiny fraction of the Sun's age), it has already burned through its reserves of hydrogen, and is evolving towards the red giant phase of its existence, after which - probably in just a few hundred thousand years - it will burst into a supernova.

This star's traditional name of Wezen comes from the Arabic for 'weight', though the intention behind the name is unclear. Indeed, it is not even sure whether the name was originally meant for Delta Canis Majoris at all, but over time it has become connected to this star. The same name, with the same origins but a slightly variant spelling, is shared by the star Beta Columbae. That star, lying less than 20° away from Wezen in the sky, is traditionally known as Wazn or Wezn, and may indeed have been the original owner of the name.


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