Triangulum Australe: Difference between revisions

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Alpha Trianguli Australis, known as Atria, is a second magnitude orange giant and the brightest star in the constellation, as well as the 42nd-brightest star in the night sky. Completing the triangle are the two white main sequence stars Beta and Gamma Trianguli Australis. Although the constellation lies in the Milky Way and contains many stars, deep-sky objects are not prominent. Notable features include the open cluster NGC 6025 and planetary nebula NGC 5979.
Alpha Trianguli Australis, known as Atria, is a second magnitude orange giant and the brightest star in the constellation, as well as the 42nd-brightest star in the night sky. Completing the triangle are the two white main sequence stars Beta and Gamma Trianguli Australis. Although the constellation lies in the Milky Way and contains many stars, deep-sky objects are not prominent. Notable features include the open cluster NGC 6025 and planetary nebula NGC 5979.


Triangulum Australe is a small constellation bordered by [[Norma]] to the north, [[Circinus]] to the west, [[Apus]] to the south and [[Ara[[ to the east. It lies near the Pointers (Alpha and Beta Centauri), with only [[Circinus]] in between.[9] The constellation is located within the Milky Way, and hence has many stars. A roughly equilateral triangle, it is easily identifiable. Triangulum Australe lies too far south in the celestial southern hemisphere to be visible from Europe, yet is circumpolar from most of the southern hemisphere.
Triangulum Australe is a small constellation bordered by [[Norma]] to the north, [[Circinus]] to the west, [[Apus]] to the south and [[Ara]]  to the east. It lies near the Pointers (Alpha and Beta Centauri), with only [[Circinus]] in between.[9] The constellation is located within the Milky Way, and hence has many stars. A roughly equilateral triangle, it is easily identifiable. Triangulum Australe lies too far south in the celestial southern hemisphere to be visible from Europe, yet is circumpolar from most of the southern hemisphere.
 
Triangulum Australe has few deep-sky objects—one open cluster and a few planetary nebulae and faint galaxies. NGC 6025is an open cluster with about 30 stars ranging from 7th to 9th magnitude. Located 3 degrees north and 1 east of Beta Trianguli Australis, it lies about 2,500 light-years (770 parsecs) away and is about 11 light-years (3.4 parsecs) in diameter.


==History==
==History==
Italian navigator Amerigo Vespucci explored the New World at the beginning of the 16th century. He learnt to recognize the stars in the southern hemisphere and made a catalogue for his patron king Manuel I of Portugal, which is now lost. As well as the catalogue, Vespucci wrote descriptions of the southern stars, including a triangle which may be either Triangulum Australe or Apus. This was sent to his patron in Florence, Lorenzo di Pierfrancesco de' Medici, and published as Mundus Novus in 1504.[2] The first depiction of the constellation was provided in 1589 by Flemish astronomer and clergyman Petrus Plancius on a 32½-cm diameter celestial globe published in Amsterdam by Dutch cartographer Jacob Floris van Langren,[3] where it was called Triangulus Antarcticus and incorrectly portrayed to the south of Argo Navis. His student Petrus Keyzer, along with Dutch explorer Frederick de Houtman, coined the name Den Zuyden Trianghel.[4]Triangulum Australe was more accurately depicted in Johann Bayer's celestial atlas Uranometria in 1603, where it was also given its current name.
Italian navigator Amerigo Vespucci explored the New World at the beginning of the 16th century. He learnt to recognize the stars in the southern hemisphere and made a catalogue for his patron king Manuel I of Portugal, which is now lost. As well as the catalogue, Vespucci wrote descriptions of the southern stars, including a triangle which may be either Triangulum Australe or Apus. This was sent to his patron in Florence, Lorenzo di Pierfrancesco de' Medici, and published as Mundus Novus in 1504.[2] The first depiction of the constellation was provided in 1589 by Flemish astronomer and clergyman Petrus Plancius on a 32½-cm diameter celestial globe published in Amsterdam by Dutch cartographer Jacob Floris van Langren,[3] where it was called Triangulus Antarcticus and incorrectly portrayed to the south of Argo Navis. His student Petrus Keyzer, along with Dutch explorer Frederick de Houtman, coined the name Den Zuyden Trianghel.Triangulum Australe was more accurately depicted in Johann Bayer's celestial atlas Uranometria in 1603, where it was also given its current name.
 
<ref>[http://en.wikipedia.org/wiki/Triangulum_Australe Triangulum Astrale]</ref>
==Etymology==
==Etymology==