The constellation Capricornus the Sea-goat is best seen at early evening in September and October. If you live in the Northern Hemisphere, and are familiar with the Summer Triangle asterism, draw an imaginary line from the star Vega and through Altair to find this arrowhead-shaped constellation low in the southern sky. At mid-northern latitudes, the huge Summer Triangle asterism hangs high in the south to overhead on autumn evenings.
No matter where you live worldwide, Capricornus climbs highest in the sky in early September around 10 p.m. local time (11 p.m. local daylight time). Because the stars return to the same place in the sky about one-half hour earlier every week, look for Capricornus highest up in mid-September around 9 p.m. (10 p.m. Daylight Saving Time). By the month’s end, look for it highest up at 8 p.m. (9 p.m. Daylight Saving Time).
By the way, as seen from the Southern Hemisphere, Capricornus appears upside-down in contrast to our northern perspective and is either overhead or high in the northern sky on September evenings.
Another way to star-hop to Capricornus from northerly latitudes is by way of the constellation Cygnus the Swan – or as others see it – the Northern Cross asterism. Draw an imaginary line from the bright Summer Triangle star Deneb through the star Epsilon Cygni to locate Capricornus the Sea-goat rather close to the horizon.
Capricornus or Capricorn?
Capricornus generally refers the constellation while Capricorn identifies the corresponding sign. Yes, there is a difference between a constellation of the Zodiac and a sign of the Zodiac!
Capricornus is a member constellation of the Zodiac, with the sun passing in front of Capricornus annually from about January 20 to February 17. However, the sun’s passage through the sign Capricorn happens from around December 21 to January 20 – about one month earlier than the sun’s passage through the constellation Capricornus. By definition, the sun enters the sign Capricorn at the December (or southern) solstice.
Think of it this way. Zodiacal signs stayed fixed relative to the solstices and equinoxes. On the other hand, the equinox and solstice points move 30o westward in front of the zodiacal constellations – backdrop stars – in a period of about 2,160 years.
In the year 131 B.C. the solstice point moved out of the constellation Capricornus and into the constellation Sagittarius. Looking into the future, the December solstice point will cross into the constellation Ophiuchus in the year 2269. These dates are based upon the constellation boundaries as defined by the International Astronomical Union in 1930.
Sky chart of the constellation Capricornus
Capricornus in starlore
The image of Capricornus as the Sea-goat is said to have come from Oannes (Adapa), the Sumerian god of wisdom. The ancient Greeks associated Capricornus with their god Pan.
Typhon, the dreadful fire-breathing monster, was about to devour Pan. But Pan turned himself into a fish – or tried to – before jumping into a river to make his great escape. However, Pan was so scared that he goofed up, changing himself into a half-goat, half-fish hodgepodge instead of a fish. In other words, Pan Pan-icked. The word panic is said to have originated from the god Pan’s misadventure with Typhon, the fire-breathing monster!
Bottom line: This post talks about the astronomical constellation Capricornus the Sea-goat (not the astrological sign). It explains how to find the constellation, and tells a few stories about it from the ancient myths.