Astronomy

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displays an aqua disk some five times larger
than Uranus.
NGC 7008, nicknamed by some the Coat
Button Nebula, is a 10th-magnitude planetary in
the nondescript northern shores of the Swan’s
coalsack, about an outstretched fist-width north-
east of Deneb, near the Cepheus border. At 60x,
NGC 7008 looks like a double blob with an elegant
skirt of nebulosity fanning off to the northwest.
Actually, this skirt is the planetary, which rounds
off at 100x. The nebula’s bright inner ring has a
dark central keyhole.
We now move some 3° south of Epsilon (ε)
Cygni, where we will expand our view from
arcseconds to degrees as we hunt down the fibrous
fragments of the Veil Nebula (NGC 6960,
NGC 6979, NGC 6992/5, and IC 1340, sometimes
collectively called the Cygnus Loop). This wreath-
like expanse consists of two likely interacting
supernova remnants that erupted some 5,000 to
8,000 years ago. Under a very dark sky, the Veil is
visible through small telescopes, appearing as two
ghostly arcs some 3° apart. Telescopically, the
eastern segment is fractured into three segments:
NGC 6992, NGC 6995, and IC 1340 (known as
the Network Nebula). The fainter, western segment
(NGC 6960, the Filamentary Nebula) caresses
52 Cygni, like a braid of hair with kinks.
Let’s now look just 15' south of magnitude 4.5
Phi (φ) Cygni to try to get a visual taste of another
Cygnus supernova remnant, Sharpless 2–91.

While the entire complex spans some 4° of sky

(and requires large telescopes to see), the remnant’s

brightest squiggle — a 20'-long anemic whisper of

light — has been spied under a dark sky through a

6-inch telescope with an Oxygen-III filter.

For an uncommon sight, seek out planetary

nebula NGC 7027, sometimes called the Pink

Pillow Nebula. This unassuming fuzzy “star” lies

only about 1½° south of Xi (ξ) Cygni. Visible in

handheld binoculars, it is one of the brightest

(magnitude 8.5), smallest (18"), and arguably most

fascinating planetary nebulae in the heavens. Seen

in the early stages of evolution, this unusual treat

appears little more than a slightly swollen ashen

star at powers up to 150x. But if the steadiness of

your sky allows you to pump up the power to 100x

per inch of aperture, you’ll see its dumbbell shape,

which may break up into knots of various

brightnesses.

Signing off

Emission nebulae, colorful gas clouds excited by

hot young stars within, glow like neon signs in

photographs, but they are visually much more

delicate creatures. One such waif lies 2¾° south-

west of Gamma Cygni: the Crescent Nebula

(NGC 6888). In this case, hot gases f leeing from

an extremely luminous and hot sun near the end

its life (a magnitude 7.5 Wolf-Rayet star) f low into

space at enormously high rates until they collide at

supersonic speeds with older shell material, caus-

ing them to glow.

The Crescent Nebula is the visible result of such

a collision. Through a telescope, the 20'-wide

nebula’s brightest segment forms a narrow crescent

along its northern and western rims; patchy

segments of dim material continue on to the

south and east, forming an annulus. But the more

southerly sections are difficult to detect through

The Crescent Nebula

(NGC 6888) is a bubble being

blown out from intensely

hot winds of a Wolf-Rayet

star. KEN CRAWFORD

The big, sprawling

open cluster M39 is

visible to the naked eye

and a wonderful sight in

binoculars. ANTHONY AYIOMAMITIS

The Cocoon Nebula

(IC 5146) is a glowing cloud

of gas surrounded by an

extensive network of dark

nebulosity. KEN CRAWFORD