Astronomy - USA (2020-08)

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Altair

Barnard’s E

AQUILA

DELPHINUS

CAPRICORNUS

SAGITTARIUS

–10°

0°

10°

21h 20h

MAP SYMBOLS

Open cluster

Globular cluster

Planetary nebula

50 ASTRONOMY • AUGUST 2020

Star clusters and planetary nebulae will

keep you looking at the Eagle all night long.

BY MICHAEL E. BAKICH

IN SUMMER, ONE OF THE

easiest star patterns to find is the

Summer Triangle. The constellation

Aquila (pronounced ACK-will-uh)

the Eagle is one of the three groups

whose Alpha stars — in this case,

Altair — make up that popular

group. This easy-to-recognize

constellation is visible from late

spring through late autumn in the

Northern Hemisphere. Its center

lies at right ascension 19h37m and

declination 3°30'.

Although the Eagle’s wingspan

might not take up as much space

as larger constellations like Hydra

(1,303 square degrees), the 22nd-

largest constellation still covers a

respectable 652.47 square degrees,

or about 1.58 percent of the night

sky. Its size undercuts its visibility,

however; it lies in the middle of the

constellation ladder (41st) in terms

of overall brightness.

The best date each year to see

Aquila is July 14, when it stands

opposite the Sun in the sky and

reaches its highest point at local

midnight. With respect to visibility,

anyone living between latitudes 78°

north and 71° south can see the

entire figure at some time during

the year. In fact, portions of it are

visible worldwide.

Aquila contains no Messier

objects or emission nebulae. Still,

as you can see, there are plenty of

targets within its borders for you

to explore with your telescope.

Good luck!

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NGC 6709

This rich open cluster sits 5°

southwest of Zeta (ζ) Aquilae.

Glowing at magnitude 6.7 (just out

of naked-eye range), it measures

13' across. Binoculars show a

concentrated glow against a

crowded stellar background.

Through a 6-inch telescope,

you’ll count some 50 stars. A

12-inch scope will more than

double that number. MARTIN C. GERMANO

Michael E. Bakich is a contributing

editor of Astronomy who enjoys slowly

moving his telescope through a single

constellation.