A little ramble through Canis Minor the Lesser Dog

 In modern mythology Canis Minor is the Lesser Dog constellation that together with Canis Major follows Orion the Hunter across the sky.

It appears not to have been known to the classical Greek astronomers it was simply referred to as rising before his companion star. It is about the time of Ptolemy c100-170 CE that it appears as a separate constellation and is therefore included in the 48 classical constellations.

There does appear to be suggestions that the stars that we refer to as Procyon and Gomeisa in Canis Minor were known to the ancient Mesopotamians as the ‘Twins’ this term dates to around 1100BCE. The Arab astronomers of a thousand years ago called the constellation Al Kalb al Makbudah or the Lesser Dog.

As the constellation is close to Orion it is seen in the winter skies, however as it follows Orion and is higher in the sky than Canis Major it can be seen later in the year into early spring. It’s a small constellation and although it contains Procyon a bright star the rest of the constellation has few bright stars and no clusters or galaxies worth mentioning.

The brightest star is alpha or Procyon or the Small Dog Star. The last of the great Arab astronomers Ulug Beg called the star Al Shamiyyah which together with other sources suggest the name of the Northern Sirius. The Euphratean astronomers called it Palura of the Cylinders, or the Star of the crossing of the Water. This name is given with reference to the River of Heaven or the Milky Way which is very close to Canis Minor. The Chinese call it Nan Ho or the Southern River.

Procyon with a magnitude of 0.3 forms part of what is called the winter triangle with the stars Sirius in Canis Major and Betelgeuse in Orion. Inside this triangle the milky way flows. Procyon is a binary system with the main star being an F class star hotter than the Sun with a small white dwarf companion which was discovered in 1896. This white dwarf is like the white dwarf companion of Sirius, its small and the material that makes it is very dense in nature. Another feature it has with Sirius is that it is relatively close to us, it is only 11.5 light years.

The only other bright star is beta or Gomeisa , there does not appear to be any ancient names attached to the star. The Arab astronomers called it either Al Gamus or Al Murzim which is the same name as Beta Canis Major in both cases the name refers to the whole constellation. Its magnitude in 2.9 and is 160 light years away, and is a B class star hotter than our Sun.

Although the milky way flows through Canis Minor there are no bright star clusters or galaxies, the ones that are here are all very faint and require reasonable size telescopes to see them and are therefore beyond the scope of our little ramble through Canis Minor.

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