Capricornus is one of the oldest constellations in the night sky. It was an important constellation in the Bronze Age as it marked the winter solstice, and it was named the goat-fish by the Sumerians four thousand years ago. To the ancient Greeks, it was Pan, the pipe-playing man-goat god. For such a historic constellation, it is visually disappointing; indeed almost impossible to make out at all. The brightest star Deneb Algedi is only magnitude 2.9 and the only other third magnitude star is Dabih, which is on the other side of the constellation. The other stars are all fourth magnitude and while Capricornus is higher in our skies than Sagittarius, its stars are still affected by extinction. It is best envisaged as a paper boat, as shown in the star chart above.

Capricornus is also lacking in deep-sky objects. There is one Messier object, the globular cluster Messier 30, catalogued by Charles Messier in 1764. While it is compact, at magnitude 6.9, reduced to 7.4 by extinction, it is relatively dim. It is nearly 13 billion years old, and 27,000 light years away. M30 is three degrees from Zeta Capricorni (mag. 3.8) in the direction of Fomalhaut in Piscis Austrinus. It is 23 arcminutes north-west of 41 Capricorni (mag. 5.2).

There are, however, three wide double stars which are more or less in a line. Algedi (Alpha Capricorni, but only the third brightest star in the constellation) has two bright stars (mag. 3.7 and 4.3) which are 381 arcseconds apart and can in theory be resolved by the naked eye. It is an optical double. They are both G type stars (like the Sun) and I see them as yellow-white. The name Algedi comes from the Arabic for goat. Below Algedi is Dabih (Beta Capricorni), with two unequal stars (mag. 3.2 and 6.1) which are closer (205 arcseconds), but still very wide. To my mind they are a more pleasing pair than Algedi. The main star is G type, but its companion is A/B and I see them as yellow and blue. It is a true binary system. Dabih comes from butcher in Arabic, possibly because a lamb (or more logically a kid) was sacrificed by the ancient Arabs when Capricornus first appeared in the dawn sky in late winter (Dabih being bright would be the first star to be spotted).

Going further down from Dabih in the same line, we reach Rho Capricorni, which is more difficult to spot as it is dimmer (mag. 4.9); it is the uppermost of a small triangle of stars. It comprises a very tight double (1.7 arcseconds) with a companion of magnitude 6.9 and a much wider double (259 arcseconds) with a 6.7 magnitude star. The tight pair is a binary star, but the wide pair is an optical double. Rho Capricorni is an F type star and the wide companion is a K type. I see them as yellow and blue (a colour inversion I have mentioned before, whereby in the presence of a yellow star, an even more yellow star is seen as various colours, including blue paradoxically).