Antlia
Channel: 宇宙のすべての知識 プリンシピア
Date: 16/01/2019

Antlia, by Wikipedia https://en.wikipedia.org/wiki?curid=1926 / CC BY SA 3.0

#Antlia
#Southern constellations
#Constellations listed by Lacaille
Antlia

Antlia (; from Ancient Greek "ἀντλία") is a constellation in the Southern Celestial Hemisphere. Its name means "pump" in Latin; it represents an air pump. Originally Antlia Pneumatica, the constellation was established by Nicolas-Louis de Lacaille in the 18th century, though its name was later abbreviated by John Herschel. Located close to the stars forming the old constellation of the ship Argo Navis, Antlia is completely visible from latitudes south of 49 degrees north.

Antlia is a faint constellation; its brightest star is Alpha Antliae, an orange giant that is a suspected variable star, ranging between apparent magnitudes 4.22 and 4.29. S Antliae is an eclipsing binary star system, changing in brightness as one star passes in front of the other. Sharing a common envelope, the stars are so close they will one day merge to form a single star. Two star systems with known exoplanets, HD 93083 and WASP-66, lie within Antlia, as do NGC 2997, a spiral galaxy, and the Antlia Dwarf Galaxy.

The French astronomer Nicolas-Louis de Lacaille first described the constellation in French as "la Machine Pneumatique" (the Pneumatic Machine) in 1751–52, commemorating the air pump invented by the French physicist Denis Papin. De Lacaille had observed and catalogued almost 10,000 southern stars during a two-year stay at the Cape of Good Hope, devising fourteen new constellations in uncharted regions of the Southern Celestial Hemisphere not visible from Europe. He named all but one in honour of instruments that symbolised the Age of Enlightenment. Lacaille depicted Antlia as a single-cylinder vacuum pump used in Papin's initial experiments, while German astronomer Johann Bode chose the more advanced double-cylinder version. Lacaille Latinised the name to "Antlia pneumatica" on his 1763 chart. English astronomer John Herschel propos...