Capricornus

Capricornus ( /ˌkæprɨˈkɔrnəs/) is one of the constellations of the zodiac; it is often called Capricorn, especially when referring to the corresponding astrological sign. Its name is Latin for "horned male goat" or "goat horn", and it is commonly represented in the form of a sea-goat: a mythical creature that is half goat, half fish. Its symbol is (Unicode ♑).

Capricornus is one of the 88 modern constellations, and was also one of the 48 constellations listed by the 2nd century astronomer Ptolemy. Under its modern boundaries it is bordered by Aquila, Sagittarius, Microscopium, Piscis Austrinus and Aquarius. The constellation is located in an area of sky called the Sea or the Water, consisting of many water-related constellations such as Aquarius, Pisces and Eridanus. It is the second faintest constellation in the zodiac after Cancer.

Notable features

Deep-sky objects

Several galaxies and star clusters are contained within Capricorn. Messier 30 is a globular cluster located 1 degree south of the galaxy group NGC 7103. The constellation also harbors the wide spiral galaxy NGC 6907.

Named stars

History and mythology

Despite its faintness, Capricornus has one of the oldest mythological associations, having been consistently represented as a hybrid of a goat and a fish since the Middle Bronze Age. First attested in depictions on a cylinder-seal from around the 21st century BCE,^[1] it was explicitly recorded in the Babylonian star catalogues as ^MULSUḪUR.MAŠ "The Goat-Fish" before 1000 BC. The constellation was a symbol of the god Ea and in the Early Bronze Age marked the winter solstice.^[2]

Due to the precession of the equinoxes the December solstice no longer takes place while the sun is in the constellation Capricornus, but the astrological sign called Capricorn begins with the solstice. The sun's most southerly position, which is attained at the northern hemisphere's winter solstice, is now called the Tropic of Capricorn, a term which also applies to the line on the Earth at which the sun is directly overhead at noon on that solstice.

In Greek mythology, the constellation is sometimes identified as Amalthea, the goat that suckled the infant Zeus after his mother Rhea saved him from being devoured by his father Cronos (in Greek mythology). The goat's broken horn was transformed into the cornucopia or horn of plenty.

The planet Neptune was discovered in Capricornus by German astronomer Johann Galle, near Deneb Algedi (δ Capricorni) on September 23, 1846, which is appropriate as Capricornus can be seen best from Europe at 4:00am in September.

Visualizations

Capricornus's brighter stars are found on a triangle whose vertices are α² Capricorni (Giedi), δ Capricorni (Deneb Algiedi), and ω Capricorni. Ptolemy's method of connecting the stars of Capricornus has been influential.^[3]

H. A. Rey has suggested an alternative visualization, which graphically shows a goat.^[4] The goat's head is formed by the triangle of stars ι Cap, θ Cap, and ζ Cap. The goat's horn sticks out with stars γ Cap and δ Cap. Star δ Cap, at the tip of the horn, is of the third magnitude. The goat's tail consists of stars β Cap and α² Cap: star β Cap being of the third magnitude. The goat's hind foot consists of stars ψ Cap and ω Cap. Both of these stars are of the fourth magnitude.

Equivalents

In Chinese astronomy, constellation Capricornus lies in The Black Tortoise of the North (北方玄武, Běi Fāng Xuán Wǔ).

Astrology

As of 2002^[update], the Sun appears in the constellation Capricornus from January 19 to February 15. In tropical astrology, the Sun is considered to be in the sign Capricorn from December 22 to January 20, and in sidereal astrology, from January 15 to February 15.

Namesakes

The USS Capricornus (AK-47/UMP45), an Andromeda-class attack cargo ship, was named after the constellation.^[5]

Citations

See also

• Capricornus (Chinese astronomy)
• IC 1337, galaxy

External links

• The Deep Photographic Guide to the Constellations: Capricornus
• Star Tales – Capricornus

Coordinates: 21^h 00^m 00^s, −20° 00′ 00″