Triangulum Australe

For the northern constellation, see Triangulum.

Triangulum Australe

Constellation
List of stars in Triangulum Australe
Abbreviation	TrA
Genitive	Trianguli Australis
Pronunciation	/traɪˈæŋɡjʊləm ɒsˈtreɪliː/, genitive /traɪˈæŋɡjʊlaɪ ɒˈstreɪls/
Symbolism	the Southern Triangle
Right ascension	16
Declination	−65
Quadrant	SQ3
Area	110 sq. deg. (83rd)
Main stars	3
Bayer/Flamsteed stars	10
Stars with planets	1
Stars brighter than 3.00m	3
Stars within 10.00 pc (32.62 ly)	0
Brightest star	α TrA (Atria) (1.91m)
Messier objects	None
Meteor showers	None
Bordering constellations	Norma Ara Circinus Apus
Visible at latitudes between +25° and −90°. Best visible at 21:00 (9 p.m.) during the month of July.

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 stars, 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.

See also

• Triangulum

References

• Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0-00-725120-9. Princeton University Press, Princeton. ISBN 978-0-691-13556-4.

External links

• The Deep Photographic Guide to the Constellations: Triangulum Australe
• Starry Night Photography: Triangulum Australe
• Star Tales – Triangulum Australe
• Triangulum Australe