Ara (constellation)
Encyclopedia
Ara is a southern constellation
situated between Scorpius
and Triangulum Australe
. Its name is Latin
for "altar
". Ara was one of the 48 Greek constellations described by the 2nd century astronomer Ptolemy
, and it remains one of the 88 modern constellations defined by the International Astronomical Union
.
, has an apparent magnitude
of 2.9. γ Arae
is a double star
just south of β. μ Arae
is believed to have at least four planets orbiting it, one of which may be rocky in nature.
The constellation's stars have no names in Western culture
, but the Chinese
call α Arae "Choo" ("club" or "staff"), and ε Arae
"Tso Kang", meaning 'left guard'.
and contains several open cluster
s (notably NGC 6200
) and diffuse nebulae (including the bright cluster/nebula pair NGC 6188
and NGC 6193
). The brightest of the globular cluster
s, sixth magnitude NGC 6397
, lies at a distance of just 6500 ly, making it one of the closest globular cluster to the solar system
.
Although Ara lies close to the heart of the Milky Way, two spiral galaxies (NGC 6215 and NGC 6221) are visible near star η Arae
.
The Stingray Nebula
(Hen 3-1357), the youngest known planetary nebula as of 2010, formed in Ara; the light from its formation was first observable around 1987.
with its smoke 'rising' southward.
, Ara was identified as the altar, made by the Cyclops
, where the gods first made offerings and formed an alliance when they were about to fight the Titans
.
, the stars of the constellation Ara lie within The Azure Dragon of the East (東方青龍, Dōng Fāng Qīng Lóng).
was a United States Navy
Crater class cargo ship
named after the constellation.
Constellation
In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....
situated between Scorpius
Scorpius
Scorpius, sometimes known as Scorpio, is one of the constellations of the zodiac. Its name is Latin for scorpion, and its symbol is . It lies between Libra to the west and Sagittarius to the east...
and Triangulum Australe
Triangulum Australe
Triangulum Australe is a small constellation in the southern sky, created in the sixteenth century. Its name is Latin for 'the southern triangle', which distinguishes it from Triangulum in the northern sky...
. Its name is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for "altar
Altar
An altar is any structure upon which offerings such as sacrifices are made for religious purposes. Altars are usually found at shrines, and they can be located in temples, churches and other places of worship...
". Ara was one of the 48 Greek constellations described by the 2nd century astronomer Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...
, and it remains one of the 88 modern constellations defined by the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
.
Stars
Ara's brightest star, β AraeBeta Arae
Beta Arae is the brightest star in the constellation Ara.Beta Arae is an orange K-type bright giant or supergiant with an apparent magnitude of +2.84...
, has an apparent magnitude
Apparent magnitude
The apparent magnitude of a celestial body is a measure of its brightness as seen by an observer on Earth, adjusted to the value it would have in the absence of the atmosphere...
of 2.9. γ Arae
Gamma Arae
Gamma Arae is a star in the constellation Ara. It is approximately 1140 light years from Earth. This is a blue-white B-type supergiant with an apparent magnitude of +3.5....
is a double star
Double star
In observational astronomy, a double star is a pair of stars that appear close to each other in the sky as seen from Earth when viewed through an optical telescope. This can happen either because the pair forms a binary star, i.e...
just south of β. μ Arae
Mu Arae
Mu Arae , often referred to by its designation in the Henry Draper catalogue HD 160691, is a main sequence G-type star around 50 light-years away from Earth in the constellation of Ara. The star has a planetary system with four known planets, three of them with masses comparable to that of Jupiter...
is believed to have at least four planets orbiting it, one of which may be rocky in nature.
The constellation's stars have no names in Western culture
Western culture
Western culture, sometimes equated with Western civilization or European civilization, refers to cultures of European origin and is used very broadly to refer to a heritage of social norms, ethical values, traditional customs, religious beliefs, political systems, and specific artifacts and...
, but the Chinese
Culture of China
Chinese culture is one of the world's oldest and most complex. The area in which the culture is dominant covers a large geographical region in eastern Asia with customs and traditions varying greatly between towns, cities and provinces...
call α Arae "Choo" ("club" or "staff"), and ε Arae
Epsilon Arae
The Bayer designation Epsilon Arae is shared by two star systems, in the constellation Ara:* ε1 Arae* ε2 AraeThey are separated by 0.54° on the sky....
"Tso Kang", meaning 'left guard'.
Deep sky objects
The northwest corner of Ara is crossed by the Milky WayMilky Way
The Milky Way is the galaxy that contains the Solar System. This name derives from its appearance as a dim un-resolved "milky" glowing band arching across the night sky...
and contains several open cluster
Open cluster
An open cluster is a group of up to a few thousand stars that were formed from the same giant molecular cloud and have roughly the same age. More than 1,100 open clusters have been discovered within the Milky Way Galaxy, and many more are thought to exist...
s (notably NGC 6200
NGC 6200
NGC 6200 is Open cluster in the constellation Ara, lying close to the galactic equator.-References:* * *...
) and diffuse nebulae (including the bright cluster/nebula pair NGC 6188
NGC 6188
NGC 6188 is an emission nebula located about 4,000 light years away in the constellation Ara. The bright open cluster NGC 6193, visible to the naked eye, is responsible for a region of reflection nebulosity within NGC 6188....
and NGC 6193
NGC 6193
NGC 6193 is open cluster containing 27 stars in the constellation Ara, visible to the unaided eye. The cluster is associated with a nearby nebulosity, NGC 6188.-List of stars in cluster:-References:* * * * * * *...
). The brightest of the globular cluster
Globular cluster
A globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
s, sixth magnitude NGC 6397
NGC 6397
NGC 6397 is a globular cluster in the constellation Ara. It is located about 7,200 light-years from Earth, making it one of the two nearest globular clusters to Earth...
, lies at a distance of just 6500 ly, making it one of the closest globular cluster to the solar system
Solar System
The Solar System consists of the Sun and the astronomical objects gravitationally bound in orbit around it, all of which formed from the collapse of a giant molecular cloud approximately 4.6 billion years ago. The vast majority of the system's mass is in the Sun...
.
Although Ara lies close to the heart of the Milky Way, two spiral galaxies (NGC 6215 and NGC 6221) are visible near star η Arae
Eta Arae
Eta Arae or IDS 16411-5852 A is a double star in the constellation Ara. It is approximately 313 light years from Earth....
.
Globular clusters
- NGC 6352
- NGC 6362
- NGC 6397NGC 6397NGC 6397 is a globular cluster in the constellation Ara. It is located about 7,200 light-years from Earth, making it one of the two nearest globular clusters to Earth...
The Stingray Nebula
Stingray Nebula
The Stingray Nebula is the youngest known planetary nebula . The Stingray is located in the direction of the southern constellation...
(Hen 3-1357), the youngest known planetary nebula as of 2010, formed in Ara; the light from its formation was first observable around 1987.
Illustrations
In illustrations, Ara is usually depicted as an altarAltar
An altar is any structure upon which offerings such as sacrifices are made for religious purposes. Altars are usually found at shrines, and they can be located in temples, churches and other places of worship...
with its smoke 'rising' southward.
Mythology
In ancient Greek mythologyGreek mythology
Greek mythology is the body of myths and legends belonging to the ancient Greeks, concerning their gods and heroes, the nature of the world, and the origins and significance of their own cult and ritual practices. They were a part of religion in ancient Greece...
, Ara was identified as the altar, made by the Cyclops
Cyclops
A cyclops , in Greek mythology and later Roman mythology, was a member of a primordial race of giants, each with a single eye in the middle of his forehead...
, where the gods first made offerings and formed an alliance when they were about to fight the Titans
Titan (mythology)
In Greek mythology, the Titans were a race of powerful deities, descendants of Gaia and Uranus, that ruled during the legendary Golden Age....
.
Equivalents
In Chinese astronomyChinese astronomy
Astronomy in China has a very long history, with historians considering that "they [the Chinese] were the most persistent and accurate observers of celestial phenomena anywhere in the world before the Arabs."...
, the stars of the constellation Ara lie within The Azure Dragon of the East (東方青龍, Dōng Fāng Qīng Lóng).
Namesakes
USS Ara (AK-136)USS Ara (AK-136)
The SS Daniel Boone sailed from New York in January 1943 with a cargo of nearly 10 tons of high explosives. Welded and chained to the deck were two locomotives. It was Capt. Larz Neilson's first voyage as a master. He had been a ship's officer for American Hawaiian Steamship Co. since graduating...
was a United States Navy
United States Navy
The United States Navy is the naval warfare service branch of the United States Armed Forces and one of the seven uniformed services of the United States. The U.S. Navy is the largest in the world; its battle fleet tonnage is greater than that of the next 13 largest navies combined. The U.S...
Crater class cargo ship
Crater class cargo ship
Crater-class cargo ship is a category of freighter that was constructed for use by the United States Navy during World War II under Maritime Commission EC2-S-C1 type....
named after the constellation.