How to Find the Aquila Constellation

Northern hemisphere summer constellations.
Northern hemisphere summer skies, looking south.

Carolyn Collins Petersen

The constellation Aquila is visible in the northern hemisphere's summer sky and the southern hemisphere's winter. This small but significant constellation features several fascinating deep sky objects that amateur astronomers can view with a backyard telescope.

Finding Aquila

Aquila constellation
Aquila is outlined in faint blue, and its brightest star is Altair. Look for it just below Cygnus the Swan and near Sagittarius. From a dark viewing site, observers can see that Aquila lies in the plane of the Milky Way. Carolyn Collins Petersen 

The easiest way to find Aquila is to locate the nearby constellation Cygnus, the Swan. It's a roughly cross-shaped pattern of stars that is high overhead on summer evenings beginning in mid-July. Cygnus appears to be flying down the Milky Way galaxy (which we see from the inside as a band of stars stretching across the sky) toward Aquila, which looks like a crooked shape of a plus sign. The brightest stars of Aquila, Lyra, and Cygnus all form a familiar asterism called the Summer Triangle, which is visible in the northern hemisphere from early summer to late in the year. 

Historical Interpretations

Aquila has been a known constellation since antiquity. It was cataloged by the astronomer Claudius Ptolemy and was eventually adopted as one of the 88 modern constellations charted by the International Astronomical Union (IAU).

Since it was first interpreted by the Babylonians, this star pattern has virtually always been identified as an eagle. In fact, the name "aquila" comes from the Latin word for "eagle." Aquila was also well known in ancient Egypt, where it was seen as a bird accompanying the god Horus. It was similarly interpreted by the Greeks and, later, the Romans, who dubbed it Vultur volans (the flying vulture).

In China, myths about family and separation were told in relation to the star pattern. Polynesian cultures saw Aquila in several different ways, including as a warrior, a tool, and a navigational star.

The Stars of the Aquila Constellation

The six brightest stars in this region make up the body of the eagle, set against a backdrop of dimmer stars. Aquila is relatively small, compared to nearby constellations.

Its brightest star is called α Aquilae, also known as Altair. It lies only about 17 light-years from Earth, making it a pretty close neighbor. The second-brightest star is β Aquilae, better known as Alshain. Its name comes from an Arabic term which means "the balance." Astronomers commonly refer to stars in this way, using lowercase Greek letters to indicate the brightest as alpha, beta, and so on, to the dimmest ones lower in the alphabet.

Aquila features several double stars, including 57 Aquilae. It contains an orange-colored star paired with a whitish-colored one. Most viewers can spot this pair using a good set of binoculars or a backyard-type telescope. Search out Aquila for other double stars, too.

A star chart showing Aquila.
The entire constellation of Aquila shown with IAU boundaries and the brightest stars that make up the pattern.  IAU/Sky & Telescope

Deep Sky Objects in Constellation Aquila

Aquila lies in the plane of the Milky Way, which means that there are a number of star clusters within its boundaries. Most are fairly dim and require good binoculars to make them out. A good star chart will help you locate these. There's also a planetary nebula or two in Aquila, including NGC 6781. It requires a good telescope to spot, and it's a favorite challenge for astrophotographers. With a powerful telescope, NGC 6781 is colorful and striking, as seen below. A view through a backyard-type telescope is not nearly so colorful, but instead shows a slightly greenish-gray "blob" of light.

A planetary nebula in Aquila.
The planetary nebula NGC 6781 as photographed through one of the telescopes of the European Southern Observatory in Chile. This nebula lies in Aquila and can be spotted with a good backyard-type telescope. ESO 

Aquila as a Springboard for Exploration

Observers can use Aquila as a jumping-off spot to explore the Milky Way and the many clusters and objects that lie in nearby constellations, such as Sagittarius. The center of our galaxy lies in the direction of Sagittarius and its neighbor Scorpius.

Just above Altair lie two tiny little constellations called Delphinus the Dolphin and Sagitta the Arrow. Delphinus is one of those star patterns that looks like its name, a cheery little Dolphin in the starry seas of the Milky Way.