Aquila (constellation)

Aquila

Abbreviation	Aql
Genitive	Aquilae
Meaning in English	the Eagle
Right ascension	20 h
Declination	+5°
Visible to latitude	Between +85° and - 75°
On meridian	July
Area - Total	Ranked 22nd 652 sq. deg.
Number of stars with apparent magnitude < 3	3
Brightest star - Apparent magnitude	Altair (α Aquilae) 0.77
Meteor showers	June Aquilids Epsilon Aquilids
Bordering constellations	Sagitta Hercules Ophiuchus Serpens Scutum Sagittarius Capricornus Aquarius Delphinus

Aquila is one of the 48 constellations listed by Ptolemy and is now also part of the list of 88 constellations acknowledged by the IAU. It lies roughly at the celestial equator. The alpha star, Altair, is a vertex of the so-called "Summer Triangle".

Table of contents

1 Notable features
2 Notable deep-sky objects
3 History
4 Mythology

Notable features

Aquila, which lies in the Milky Way, contains many rich starfields.

α Aql: also known as Altair (Arabic for eagle) this multiple star system (3 components) has 0.77m and is of spectral type A7 V.
β Aql (Alshain): its spectral type is G8 IV and it shines with an apparent brightness of 3.71m. Like Altair, it too is a multiple star system with three components.
γ Aql (Tarazed): spectral type K3 II; 2.72m
η Aql: This variable star is one of the brightest classical Cepheids; its brightness varies between 3.48 mag and 4.39 mag every 7.177 days.
15 Aql: This double star is a yellow K star of 5.4 mag accompanied by a 7th mag star; it can easily be observed with small telescopes.

Notable deep-sky objects

Two interesting planetary nebulae lie in Aquila:

NGC 6803 shows a small but bright ring
NGC 6781 which bears some resemblance with the Owl Nebula in Ursa Major.

More deep-sky objects:

NGC 6709: an open cluster of 6.7m
NGC 6755: an open cluster of 7.5m
NGC 6760: a globular cluster of 9.1m

History

Two major novae have been observed in Aquila; the first one was in 389 BC and was recorded to be as bright as Venus, the other shone brighter than Altair.

Mythology

Aquila is Latin and means eagle. The constellation is said to represent the eagle which, in classical Greek mythology, carried the thunderbolts of Zeus and was sent by him to carry the shepherd boy Ganymede, represented by the neighbouring Aquarius, to Mount Olympus where he became the wine-pourer for all the gods. This explains why the largest moon of Jupiter was called Ganymede, Jupiter being the Roman name of Zeus.

This constellation was also known as Vultur volans to the Romans, not to be confused with Vultur cadens which was the Romans' name for what is now known as Lyra.

Aquila also represents one of the Stymphalian Birds killed by the Greek hero Heracles during his Sixth Labour.

In the Chinese love story of Qi Qiao Jie, Niu Lang (Altair) and his two children (Aquila -β and -γ) are separated forever from their mother Zhi Nu (Vega) who is on the far side of the river, the Milky Way.