Aquila

Characteristics of Aquila

Aquila, the Eagle, is a constellation that graces the celestial sphere with its presence. This constellation is the 22nd largest, covering an area of 652 square degrees in the sky. It is situated in the fourth quadrant of the northern hemisphere (NQ4) and can be seen at latitudes between +90° and -75°. Aquila is bordered by several constellations including Aquarius, Capricornus, Delphinus, Hercules, Ophiuchus, Sagitta, Sagittarius, Scutum, and Serpens Cauda.

Discovery and Age

The constellation of Aquila was one of the 48 constellations listed by the 2nd-century astronomer Ptolemy. It has been known since antiquity, with earlier mentions by Eudoxus in the fourth century BC and Aratus in the third century BC. The International Astronomical Union now recognizes it as one of the 88 modern constellations. Aquila is often associated with the eagle that carried Zeus/Jupiter’s thunderbolts in Greco-Roman mythology.

Visibility

Aquila is prominently visible in the northern hemisphere’s summer skies, situated along the Milky Way. This positioning makes it a constellation rich in clusters and nebulae, although many are dim and galaxies are sparse within its borders. Its brightest star, Altair, is one vertex of the Summer Triangle asterism, making it easier to locate in the night sky.

Aquila is visible from both the northern and southern hemispheres. However, its best visibility is during the months of July through October in the northern hemisphere, making it essentially a summer constellation. In the southern hemisphere, its visibility corresponds with the northern hemisphere’s summer months.

Deep Sky Objects

Despite not housing any Messier objects, Aquila is home to several notable deep sky objects. These include the Phantom Streak Nebula (NGC 6741), an example of a planetary nebula located approximately 7,000 light years away, and NGC 6709, an open star cluster that can be observed with a small telescope. NGC 6755 is another open cluster within Aquila, consisting of about a dozen stars.

Meteor Showers

Aquila hosts two meteor showers: the June Aquilids and the Epsilon Aquilids. These meteor showers provide a celestial spectacle for observers, marking Aquila as not just a constellation of historical and mythological significance but also as a site for dynamic astronomical events.

How to Identify Aquila

To find Aquila in the sky, look for its brightest star, Altair, which is part of the Summer Triangle asterism. The constellation is located along the Milky Way, which makes it a region rich in nebulae and star clusters, albeit galaxies are rare due to the galactic core obscuring the view beyond our Milky Way.

The Brightest and Largest Stars

Altair stands out as both the brightest and one of the closest stars visible to the naked eye within the Aquila constellation. It is an A-type main-sequence star, notable for its rapid rotation which flattens its poles. Another significant star is Tarazed (Gamma Aquilae), an orange giant approximately 461 light years away, shining with a visual magnitude of 2.72.

Mythology

Aquila represents the eagle in Greco-Roman mythology, known for carrying Zeus/Jupiter’s thunderbolts. It is also associated with the eagle that kidnapped Ganymede to Mount Olympus to serve as the cup-bearer to the gods.

This detailed exploration of Aquila reveals its significance on multiple fronts, from its rich mythological roots to its role in modern astronomy as a guide for identifying celestial objects and enjoying meteor showers.