Astronomy - USA (2020-08)

5

11

NGC 6804

NGC 6738

NGC 6781

NGC 6755

NGC 6756

NGC 6749

NGC 6760

NGC 6741

NGC 6772

NGC 6751

NGC

6709

¡

c

i

h

b

t

V^12

SCUTUM

SERPENS CAUDA

OPHIUCHUS

HERCULES

19h

WWW.ASTRONOMY.COM 51

NGC 6741

This planetary nebula, which

observers call the Phantom

Streak, lies 4.5° north-northwest

of Lambda Aquilae. With a

magnitude of 11.4 and a diameter

of 6", it’s a tough catch through

small scopes. Through an 11-inch

telescope at high powers, the

disk will look larger than the

other similarly bright stars in

the field of view. ESA/HUBBLE AND NASA

NGC 6749

This globular cluster — one of

the least concentrated known

— is a challenge to spot even

through large scopes. It glows

at magnitude 12.4, measures 6.3'

across, and lies 5° west-southwest

of Delta (δ) Aquilae. Through a

12-inch instrument, NGC 6749 is

only a soft haze whose central

region is slightly brighter than

the halo. MARTIN C. GERMANO

NGC 6781

This planetary nebula glows at

magnitude 11.4 and measures

109" across. It lies 3.8° north-

northwest of Delta Aquilae. Peer

through an 8-inch scope, and

NGC 6781 will stand out against a

starry background. An Oxygen-III

filter will help a lot. The disk

appears soft, irregular, and oval-

shaped with a slightly darker

center. ADAM BLOCK/NOAO/AURA/NSF

NGC 6804

This 12th-magnitude planetary

nebula lies almost 2° north-

northwest of Mu (μ) Aquilae.

You’ll see its 31"-wide disk

through scopes as small as

6 inches. At high powers, NGC

6804 looks diffuse. If you use an

Oxygen-III filter, you’ll see a

broken ring of gas that surrounds

the 14th-magnitude central star.

LIBBY HARRELL/ADAM BLOCK/NOAO/AURA/NSF

Barnard’s E

To find this great combo object,

point your binoculars at yellow

Tarazed (Gamma [γ] Aquilae).

With the star centered, Barnard’s

E will appear 1.4° to the west-

northwest. Barnard 143 (B143) is

the easier of the pair to spot. It’s a

narrow U with two bars about 15'

long, oriented east-west. B142,

just to the south, is a single line

and not as dark. ROBERTO FERRERO

NGC 6772

This large planetary nebula (62"

across) lies 3° northeast of Lambda

Aquilae. Because it glows softly at

magnitude 12.7, it’ll be difficult to spot

through an 8-inch telescope. A 12-inch

instrument will reveal its circular

structure, and perhaps you’ll even see

a hazy edge and a slight north-south

elongation. Use a nebula filter to

guarantee success. GUNNAR HURTIG/ADAM

BLOCK/NOAO/AURA/NSF

NGC 6751

This magnitude 11.9 planetary

nebula sits 1° south of Lambda

(λ) Aquilae. Through a scope

with an aperture of 14 inches or

more, you’ll see two stars, each

a magnitude fainter than the 20"-

wide planetary, flanking it to the

east and west. The central star

is a tough catch, but high

magnification helps. NASA/ESA/

THE HUBBLE HERITAGE TEAM (STScI/AURA)

NGC 6755 and NGC 6756

These two open clusters lie 3°

east of Theta (θ) Serpentis. NGC

6755 is brighter (magnitude 7.5)

and larger (14') than NGC 6756

(magnitude 10.6, 4' across).

Through a 6-inch scope at

medium magnification, both

clusters stand out from the Milky

Way background, although NGC

6755 does so more easily.

BERNHARD HUBL