Sky & Telescope - September 2020 - 63

Outback
the chart plots a sparse open cluster (NGC 7686), a prominent planetary nebula (NGC 7662), a sizable edge-on galaxy
(NGC 7640), and several double stars. I attacked the ﬁeld
from a high-elevation "dark park," employing my 18-inch f/4.5
Dobsonian, then later from my suburban yard using smaller
scopes. Surprisingly, the city observations weren't futile.

Hiding in Plain Sight
First, the country views. A dedicated star-hopper, I planned
my route around the 4th-magnitude stars Lambda (λ), Kappa
(κ), and Iota (ι) Andromedae located about 15° north of the
Great Square. The trio bends northwestward toward a ragged
and less conspicuous curve highlighted by 3, 5, 7, 8, and 11
Andromedae. I familiarized myself with the area in binoculars, then grabbed my voice recorder and took to the telescope.
After locating 5th-magnitude 8 Andromedae in my 8×50
ﬁnderscope, I shifted the 18-incher eastward 2° to an important pair of stars just shy of 5′ apart. Orangey 6.2-magnitude
HD 221246 and creamy-white 7.7-magnitude HD 221203
overlie the open cluster NGC 7686. Unfortunately, the
brighter beacon - HD 221246 - almost obliterates this
+50°

α
22h
LACERTA

0h

23h

φ

7686

λ

μ

κ

ν

M110
M31

M32

ANDROMEDA

ι

+50°

CAS

7
8
11
Σ2985

7686
7662

+40°

+48°

7640

β

π
δ
α

η

β

PSC

+30°

LAC

+46°

Σ3034

κ

Σ3004

Σ2973

ι
λ

PEGASUS

3
5

λ

ψ

+44°

μ

γ

relatively obscure group. Indeed, there's no ﬁrm agreement
that NGC 7686's several dozen stars, scattered across 15′ of
sky (and of uncertain distance), add up to a true cluster. And
yet, as my tape-recorded initial impression attests, "I'm glad I
tracked this down. There's deﬁnitely something here."
Ofﬁcially, NGC 7686 shines at magnitude 5.6, but this
value includes my two beacon stars. Many of the members
are fainter than 9th magnitude. In the big Dob at 69× (my
lowest magniﬁcation), I traced a raggedy zigzag of perhaps
a dozen 9th- to 12th-magnitude stars running west-northwestward across the cluster's northern perimeter. I followed
a tighter chain of eight or nine 11th- to 13th-magnitude stars
trending in the same direction from HD 221203. In between
the approximately parallel chains, I detected some weaker
pinpricks plus a grainy background suggesting more stars.
Wanting to zoom in for a better look while still containing
the entire cluster in one pleasing view, I selected an ultrawide-ﬁeld eyepiece of 13-mm focal length. Delivering 158×,
the ultra-wide resolved the grainy mixture into at least two
dozen stars, though the ones closest to the orange beacon
were trying awfully hard not to be seen!

+20°

+42°

HD 220822

13
7662

ο

V385

ANDROMEDA

α
+10°

+40° 23h 40m

23h 30m

Star magnitudes

1h

Exploring northwestern Andromeda
reveals subtle but satisfying wonders,
such as the Blue Snowball Nebula.

4
5
6
7
8
9

7640

23h 20m

23h 10m

23h 00m

p PEGASUS POINTS THE WAY . . . TO THE ANDROMEDA OUTBACK The author's starting point for his exploration of what he fondly calls the
Andromeda Outback is a trio of stars located about 15° north of the Great Square of Pegasus. Lambda, Kappa, and Iota Andromedae, identified here,
are also plotted (though not labeled) on this month's centerfold star chart.
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Sky & Telescope - September 2020

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