Star Constellation Facts: Capricornus, the Sea-Goat

Star Constellation Facts: Capricornus, the Sea-Goat
Alexander Jamieson’s Celestial Atlas (1822)

Capricornus, meaning “horned goat” in Latin, is the smallest of the zodiac constellations, as well as the second faintest after Cancer. Notice I called it the constellation Capricornus which is its proper astronomical name, and not Capricorn which is the name given to the astrological sign of the zodiac. This faint constellation’s brightest star, Deneb Algedi, is of magnitude 2.85, and is actually a multiple system whose primary component is a white giant star located 39 light-years distant.

Location: A Southern Constellation

Capricornus is the 40th biggest constellation in the sky, and is visible for observers located between latitudes +60° and -90°. It can be seen low on the southern horizon between Aquarius and Sagittarius and is located in an area of the sky known to the ancients as the Sea. This region is rich in constellations with water-related themes, such as Pisces, Aquarius and Eridanus. From northern latitudes Capricornus can be seen from July to November, and in the Southern hemisphere from winter to late spring, where its appears upside down relative to the Northern hemisphere.

Best Seen: Autumn

Being on the ecliptic, Capricornus is visible from almost anywhere on the globe, and in the Northern hemisphere is best viewed from July to November, while in the Southern hemisphere it is best viewed in winter and spring time.

Mythology: Represents a She-Goat

Although Capricornus is said to represent Amalthea, the she-goat that suckled Zeus as an infant, in some myths the constellation is also said to represent the half man half goat god called Pan. According to Greek legends, when Gaia, mother Earth, sent the monster Typhon to attack the Olympian gods, Pan suggested that they all transform themselves into animals in order to help them hide in plain sight of the Titans. Pan then took refuge in Capricornus, the Sea-Goatthe Nile River turning his lower half into a fish and when he noticed that Typhon was attempting to destroy Zeus, he blew a shrill note on his pipes which made Typhon flee. Zeus later turned Pan into one of the signs of the zodiac in appreciation of his heroic deed.

Shape: Triangular

Capricornus is one of the faintest constellations, which makes it even harder to discern the shape of a goat. From the southern hemisphere, it is possible to make out the shape of a rhinoceros horn, but from the far northern hemisphere, the constellation looks distinctly triangular, and appears more like a kite, or perhaps a Chinese fan.

Notable Stars: Deneb Algedi (2nd Magnitude)

The three brightest stars in Capricornus are Deneb Algedi (2.85), Dahbi (3.05), and Omega Capricorni (4.12). The brightest star is called Deneb Algedi (left), meaning “the tail of the goat” in Arabic, and is actually a multiple star system which consists of four stars, with the most luminous component, Delta Capricorni A, being a white giant star that is 8.5 times as bright as the Sun. Dahbi (top right) is 5+ star system that is 328 light years away, while Omega Capricorni (bottom right) is 630 light years distant, and in most depictions is show as the goat’s front foot, although is sometimes called the “Belly of the Goat”.

Notable Objects: Globular Cluster M30

– Messier 30 (NGC 7099) is the main noteworthy deep sky object in the constellation, a globular cluster about 28,000 light years away, but approaching us at about 182 km/sec. It is about 90 light years in diameter, and can be found just below and right of Deneb Algedi, although you’ll need a telescope or binoculars to study this globular cluster because of its 7.5 magnitude. M30, however, is one of the easier globular clusters to spot, and can be found SSE low in the sky.

Other deep space objects of interest in this constellation include the elliptical galaxy NGC 7103, and the spiral galaxy NGC 6907.

Planets: 9+ Known

All told, there are 5 stars in the constellation that host 9 planets between them, with one planet having a potentially habitable moon.

Meteor Showers: 5

Capricornus: The Sea Goat

The Sea Goat Capricornus is home to 5 meteor showers, including;

– The Alpha Capricornids usually runs from July 15th to about September 11th, with the peak usually occurring around August 1st when 6 to 14 meteors per hour can be seen. This shower is known for having really bright meteors and occasional fireballs. Lasting almost a month you get plenty of time to take a peek.

– The Chi Capricornids run from Jan 29th to Feb 28th, and peak on Feb 13th. This meteor shower is associated with the asteroid Adonis, but it occurs during the daytime and so is only detectable by radio observations.

– The Sigma Capricornids is active from about June 18th to July 30th, with the peak expected to occur on June 27th. However, it is a very light shower that produces around 2 meteors per hour, and therefore is often missed, especially with the volume of other showers taking place in this part of the sky at this time of year.

– The Tau Capricornids is regarded as a minor shower that runs from June 16th to July 29th, with a peak on July 12th. However, meteors from this shower are best observed telescopically, which might make tracking individual meteors difficult.

– The Capricorniden-Sagittarids shower takes place on Feb 1st, but is a daytime shower, so unless you own a radar set you won’t be watching this one.

Astrology: Dec 22 to Jan 19

In astrology, the Sun enters Capricornus on 21st/22nd December, marking the beginning of the winter solstice and the shortest day in the northern hemisphere. These dates, however, hark back to the early Bronze Age, and due to precession over time the winter solstice is now actually marked by the Sun entering Sagittarius on this date. These days the Sun actually passes in front of the constellation Capricornus from around January 20th to February 16th, a full month later. Other astrological associations include the following:

Date of Birth: Dec 22 to Jan 19
Sign Ruler: Saturn
Element: Earth
Birth Stone: Agate, Garnet, Vesuvianite
Metal: Lead
Color: Brown, black, dark green
Characteristics: Intelligent, practical, reliable, generous, optimistic, persistent
Compatibility: Virgo, Taurus and Pisces

History and Star Lore

Back in the year 149 CE there was an early Greek astronomer named Ptolemy who identified 48 of the most common constellations of the time. Capricornus was amongst them, but its story can be traced all the way back to the Sumerians who settled the area (now called Iraq) between 5500 and 4000 BCE, and referred to it as being a hybrid of a goat and a fish. Eventually the Greeks got a hold of the story, and tied it to the god of nature, Pan. Interestingly, in Greek mythology Cancer is known as the ‘Gate of Men’ where souls return to Earth to enter newborns, while Capricornus is known as the ‘Gate of the Gods’, where the souls of the dead return to heaven.