Triangulum Australe
Encyclopedia
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 derives from its three brightest star
s, of second and third magnitude
, which form an approximately equilateral triangle.
The invention of this constellation is obscure but can be attributed to 16th century seafarers. It was introduced in 1589 by Petrus Plancius
on a 32½-cm diameter celestial globe published in Amsterdam by Jacob Floris van Langren. Triangulum Australe acquired its present form and position on a 35-cm diameter celestial globe published in 1597 (or 1598) in Amsterdam by Plancius with Jodocus Hondius
. It was first depicted in a celestial atlas in the Uranometria
of Johann Bayer
in 1603.
Its notable features include NGC 6025
, an open cluster
with about 30 stars ranging from 7th to 9th magnitude.
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....
in the southern sky, created in the sixteenth century. 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 'the southern triangle', which distinguishes it from Triangulum
Triangulum
Triangulum is a small constellation in the northern sky. Its name is Latin for triangle, and it should not be confused with Triangulum Australe in the southern sky. Its name derives from its three brightest stars, of third and fourth magnitude, which form a nearly isosceles long and narrow triangle...
in the northern sky. Its name derives from its three brightest star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s, of second and third 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...
, which form an approximately equilateral triangle.
The invention of this constellation is obscure but can be attributed to 16th century seafarers. It was introduced in 1589 by Petrus Plancius
Petrus Plancius
Petrus Plancius was a Dutch astronomer, cartographer and clergyman. He was born as Pieter Platevoet in Dranouter, now in Heuvelland, West Flanders. He studied theology in Germany and England...
on a 32½-cm diameter celestial globe published in Amsterdam by Jacob Floris van Langren. Triangulum Australe acquired its present form and position on a 35-cm diameter celestial globe published in 1597 (or 1598) in Amsterdam by Plancius with Jodocus Hondius
Jodocus Hondius
Jodocus Hondius , sometimes called Jodocus Hondius the Elder to distinguish him from his son Henricus Hondius II, was a Flemish artist, engraver, and cartographer...
. It was first depicted in a celestial atlas in the Uranometria
Uranometria
Uranometria is the short title of a star atlas produced by Johann Bayer.It was published in Augsburg, Germany, in 1603 by Christophorus Mangus under the full title Uranometria : omnium asterismorum continens schemata, nova methodo delineata, aereis laminis expressa. This translates to...
of Johann Bayer
Johann Bayer
Johann Bayer was a German lawyer and uranographer . He was born in Rain, Bavaria, in 1572. He began his study of philosophy in Ingolstadt in 1592, and moved later to Augsburg to begin work as a lawyer. He grew interested in astronomy during his time in Augsburg...
in 1603.
Its notable features include NGC 6025
NGC 6025
NGC 6025 is an open cluster located 2,700 light years away in the Triangulum Australe constellation. It was discovered by Abbe Lacaille in 1751 or 1752 during his South Africa tour.-External links:**-References:...
, an 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...
with about 30 stars ranging from 7th to 9th magnitude.