'Aquila' (
IPA: , ; sometimes named the ''Vulture''), is one of the 48
constellations listed by
Ptolemy, also mentioned by
Eudoxus (4th century BC) and
Aratus (3rd century BC) and 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
Summer Triangle asterism.
Ptolemy catalogued nineteen stars jointly in this constellation and in the constellation
Antinous, which was named in the reign of the emperor
Hadrian (AD 117–138), but sometimes, and wrongly, attributed to
Tycho Brahe, who catalogued twelve stars in Aquila and seven in Antinous;
Hevelius determined twenty-three stars in the first, and nineteen in the second.
Notable features
Aquila, which lies in the
Milky Way, contains many rich starfield.
★ α Aql (
Altair): this multiple star system (3 components) has 0.77m and is of spectral type A7 V. It has a parallax of 0.23", and consequently is about eight times as bright as the sun.
★
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 short-period
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
Three interesting
planetary nebulae lie in Aquila:
★
NGC 6804 shows a small but bright ring
★
NGC 6781 which bears some resemblance with the
Owl Nebula in
Ursa Major.
★
NGC 6751: also known as the
Glowing Eye, a planetary nebula
More deep-sky objects:
★
NGC 6709: an
open cluster of 6.7m located five degrees southwest of Zeta Aquilae
★
NGC 6755: an
open cluster of 7.5m; it is made up of about a dozen stars with magnitudes 12 thru 13
★
NGC 6760: a
globular cluster of 9.1m
★
NGC 6749: an
open cluster
★
NGC 6778:
planetary nebula
★
NGC 6741:
planetary nebula
★
NGC 6772:
planetary nebula
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 (
Nova Aquilae 1918) briefly shone brighter than Altair, the brightest star in Aquila.
Depicted as an eagle, Aquila is named for the bird that belonged to Zeus. Aquila's most famous task was carrying the mortal Ganymede to the heavens to serve as Zeus' cup bearer.
Mythology
The constellation resembles a wide winged, soaring, short necked, bird, which the ancients identified as an eagle
[1]. In classical
Greek mythology, it was identified as the eagle which carried the thunderbolts of
Zeus and was sent by him to carry the shepherd boy
Ganymede who he desired, 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, together with other constellations in the
Zodiac sign of
Sagittarius (specifically,
Lyra,
Cygnus), may be a significant part of the origin of the myth of the
Stymphalian birds, one of
The Twelve Labours of
Herakles. The constellation could also have originated from the eagle
Ethon, the tormentor of
Prometheus, and offspring of the monsters
Typhon and
Echidna.
In the Chinese love story of
Qi Xi, Niu Lang (
Altair) and his two children (β and γ Aquilae) are separated forever from their wife and mother Zhi Nu (
Vega) who is on the far side of the river, the
Milky Way.
In
Hinduism, the Aquila consellation is identified with the half eagle, half human deity,
Garuda.
References
★
★ Ian Ridpath and Wil Tirion (2007). ''Collins Stars and Planets Guide'', HarperCollins, London. ISBN 978-0007251209.
External links
★
The Deep Photographic Guide to the Constellations: Aquila
★
NightSkyInfo.com: Constellation Aquila
★
'WIKISKY.ORG': Aquila constellation
★
Star Tales – Aquila