CAPRICORNUS

The Sea Goat

Capricornus - Alexander Jamieson - 1822

The constellation Capricornus, the sea goat, is depicted as a goat with the tail of a fish, and has been for over three thousand years. The origins of this unlikely and improbable creature are lost in antiquity. Some say the figure of a goat was given the tail of a fish because it is in an area of the sky historically known as the sea. Other tales refer to the ancient Greek god Pan, half goat, half man, who leaped into the sea and disguised himself as half goat, half fish, to escape the monster Typhon. Whatever the source of the figure, it is recognized as a sea goat to this day.

Alpha Capricorni is only the third brightest star in the constellation, given the alpha designation because it represents the head of the figure. It is called Al Giedi, Arabic for the goat. It is an optical binary system, two stars that appear close together (almost as one to the naked eye) from our perspective on Earth, but are completely independent and separated by vast distances. Prima Giedi has a magnitude of 4.3, and is very far away at a distance of 690 light years. Secunda Giedi is actually the brighter of the two with a magnitude of 3.58, and is very much closer, at a distance of 109 light years.

Beta Capricorni is indeed the second brightest star in Capricornus, named Dabih, meaning butcher, presumably because goats were routinely butchered for their meat. Unlike Al Giedi, it is a true binary system, consisting of two stars in orbit about each other, 328 light years away. They are known as Dabih Major, which has a magnitude of 3.05, and Dabih Minor, with a magnitude of 6.09.

Gamma Capricorni is named Nashira, Arabic for bearer of good news. What that good news might be is a mystery lost to the ages. It is 139 light years away, with a magnitude of 3.68.

Delta Capricorni, although given the fourth letter of the Greek alphabet, has a magnitude of 2.87, and is the brightest star in the constellation. It is named Deneb Algiedi, the Arabic term for tail of the goat.

M30

M30 (NGC 7099) - Globular Cluster - Hubble Space Telescope - December, 2009

HCG 87

Hickson Compact Group 87 - Hubble Space Telescope - September, 1999

Exoplanets

Four planets have been discovered so far in Capricornus. There are all massive gas giants many times larger than Jupiter, orbiting very dim stars very far away - except one. Planet GI 785b is much smaller than Jupiter, only about 20 times larger than Earth. And the star it orbits is one of our closest neighbors, only 29 light years away. The star, GI 785 (HR 7722), has a magnitude of 6.13, putting it just beyond the reach of most naked eye observers, but it is easily found in binoculars, or a small telescope.

Alphabetical Links to the Constellations

ANDROMEDA AQUARIUS AQUILA ARIES AURIGA BOOTES CAMELOPARDALIS CANCER CANES VENATICI CANIS MAJOR CANIS MINOR CAPRICORNUS CARINA CASSIOPEIA CENTAURUS CEPHEUS CETUS COLUMBA COMA BERENICES CORONA AUSTRALIS CORONA BOREALIS CORVUS CRATER CRUX CYGNUS DELPHINUS DORADO DRACO EQUULEUS ERIDANUS FORNAX GEMINI HERCULES HYDRA LACERTA LEO LEO MINOR LEPUS LIBRA LUPUS LYNX LYRA MONOCEROS OPHIUCHUS ORION PEGASUS PERSEUS PISCES PISCIS AUSTRALIS PUPPIS SAGITTA SAGITTARIUS SCORPIUS SCULPTOR SCUTUM SERPENS SEXTANS TAURUS TUCANA URSA MAJOR URSA MINOR VIRGO VULPECULA