AlbireoAthebyne1
2
3
AlderaminWSadNCP PolarisURSA MINORAlmachPERSEUSLACERTACASSIOPEIACEPHEUSANDROMEDAVegaLY R A`_CYGNUSPEGASUSDenebDRACOWWW.ASTRONOMY.COM 45
W REGION 1
Athebyne is a challenging binary system.
The 3rd-magnitude yellow primary has a
9th-magnitude pip of light 5" to the south-
east. Try magnifications ranging from
200x to 300x in late twilight. A 2 ̊ sweep
eastward brings us to the 12th-magnitude
galaxy NGC 6223. While this highly con-
centrated (3.5' by 2.5') system may appear
desolate, in high-resolution images it’s a
mystifying concoction of warped spiral
arms, a double nucleus, and an extended
and misshapen outer elliptical halo.
Let’s return to Athebyne and look 6 ̊
east-southeast to find the binary star
Struve 2155. The 7th-magnitude yellow
primary has a 10th-magnitude blue com-
panion 10" to the east-southeast. This dim
cousin to Albireo shares the same field of
view with the mystifying orange giant star
VW Draconis. In 1911, this star was listed
as variable, ranging in photographic mag-
nitude from 6.0 to 7.0 every 170 days, but
it has since been “demoted” to a star of
constant brightness. Take a look at it once
a month for three or four months and see
what you think. Now move about 10 ̊ east-
southeast to 4.5-magnitude Omicron (ο)
Draconis, a pumpkin orange star with an
8th-magnitude lavender companion some
34" to the southwest.
A phenomenal pairing of deep-sky
objects lies about 2 ̊ southwest of 3.5-
magnitude Eta Cephei: 9.5-magnitude
NGC 6946, known as the Fireworks
Galaxy in Cygnus; and 8th-magnitude
NGC 6939, an open cluster just less than
a degree to the north-northwest, in
Cepheus. NGC 6946’s ghostly pale
10'-wide disk is a fitting match for its clus-
ter companion, which appears as an orb of
similarly bright scintillating points against
a smoldering background of dimmer suns.
Reversing direction, we drop our gaze
to 4th-magnitude Iota (ι) Cygni, and look
nearly 3 ̊ west-southwest for Struve 2486
— near twin yellow stars (magnitudes 6.6
and 6.8) separated by 8". Its “big brother,”
16 Cygni, performs only 4½ ̊ to the east
and slightly north, displaying two yellow
6th-magnitude stars separated by 40".
What’s more, the 9th-magnitude Blinking
Planetary (NGC 6826) lies in the same
field of view ½ ̊ to the east-southeast. The
30"-wide nebula displays a pale blue-green
disk and appears to blink (swell and
contract) as you alternate between
averted and direct vision, respectively.
Let’s now center 4th-magnitude R
Lyrae (also known as 13 Lyrae) in our
telescopes and move 2 ̊ northeast to the
11th-magnitude face-on lenticular galaxy
NGC 6703. This tiny glow with a bright
core has a magnitude 13 elliptical com-
panion, NGC 6702, about 15' to its north-
northwest; through an 8-inch telescope at
moderate power, I first mistook the latter
for a star because it’s so tiny (1.8').
Zigging east-southeast to 3rd-
magnitude Delta (δ) Cygni, we now look
about 1¾ ̊ northeast for the 7th-magnitude
open cluster NGC 6811. Popularly known
as the “Hole in the Cluster,” this aptly
named visual enigma looks, at a glance,
like an amorphous smoke ring. But with
more power, the smoke dissolves into a
sparkling annulus of twinkling starlight.
The cluster’s unusual distribution of stars
— including a dense corona of brighter
stars around the cluster’s center —
explains the visual hole.
Returning to Delta Cygni, we slip about
5 ̊ south-southwest for a lovely CarolineHerschel discovery: the 7th-magnitude
Fox Head Cluster (NGC 6819). This rich
and highly concentrated (5') spangle was
once mistakenly listed as a globular cluster.
We end our tour of Region 1 by center-
ing 4th-magnitude Theta (θ) Lyrae in our
telescopes and looking about 1 ̊ east-
southeast for the magnitude 9.5 open clus-
ter NGC 6791. This galactic phantom’s
pale and paltry stars span 16' of sky. But
don’t let that dissuade you from looking;
German astronomer Friedrich Winnecke
discovered this cluster using only a 3-inch
telescope in 1853.ABOVE: Three golden double stars — Athebyne,
Albireo, and Almach — mark the vertices of the
Golden Triangle. For our purposes, we’ll divide the
area into three roughly equal regions, all of which
are ripe for further exploration. ASTRONOMY: ROEN KELLYMIDDLE: Open cluster NGC 6811 is packed with
about 1,000 stars, but a relative void near the center
explains why it’s commonly referred to as the Hole
in the Cluster. ANTHONY AYIOMAMITISBELOW: At about 8 billion years old, open cluster
NGC 6791 in the constellation Lyra is one of the
oldest (and largest) open clusters in the night sky.
CHUCK KIMBALL