Sky & Telescope - September 2019 - 56

SEPTEMBER 2019 OBSERVING
Deep-Sky Wonders

NGC 6802 is a beautiful diamond-dust
cluster rich in faint and very faint stars.
It lies at an estimated distance of about
7,000 light-years, and it's dimmed by
intervening dark clouds that seem to
split the softly shining band of Milky
Way in this area of the sky.
Now let's move 1.7° east-northeast
of Alpha to Stock 1. Through my
4.1-inch scope at 17×, this is a large,
loose cluster of 20 moderately bright
and many very faint stars. An 8thmagnitude star sits at the heart of a
core group measuring 30′ × 20′. This,
in turn, is surrounded by a 1.4° halo
of stars, mostly encircling the eastern half of the core. A reddish orange
star adorns the western reaches of the
cluster. Stock 1 contains many double
stars. The brightest is Σ2548, located 14′
southeast of the cluster's central star.
Its 8.5- and 9.9-magnitude components
can be split at about 50×. A recent study
indicates that most of this cluster's
true members are roughly concentrated
within the core group's ½° diameter.
Our ﬁnal stop will be the dark
nebula LDN 810, which I like to call the
Coalman. The simplest way to ﬁnd it is
to scan 3.3° due east from Albireo, the

p The author sees the dark nebula LDN 810 as the negative image of a snowman and thus calls it
the Coalman.

beautiful gold-and-blue double star that
marks the head of Cygnus, the Swan.
With my 10-inch scope at 68×, I see a
north-south oval of inky darkness containing only a few extremely faint stars.
A slightly less conspicuous dark oval
perched atop it turns the nebula into
a ﬁlled-in 8 or the negative image of a
snowman. The southern patch is about
9′ × 6′ and the northern one 6′ × 5′.

These are just a few of the foxy residents of Vulpecula. In the October 2006
issue, this tour continues with more
vulpine delights, including the constellation's brightest planetary nebula and
its ﬁnest cluster.
¢ Contributing Editor SUE FRENCH
penned this column for the September
2006 issue of Sky & Telescope.

Fox Hunt
Type

Mag(v)

Size/Sep

MSA

PSA

Alpha (α) Vul

Double star

4.4, 5.8

7.1′

+24° 40′

1196

NGC 6800

Open cluster

15′

19h 27.1m

+25° 08′

(1196)

NGC 6793

Open cluster

7′ core, 18′ halo

19h 23.2m

+22° 08′

(1196)

(65)

h886
Collinder 399

Double star

10.5, 11.5

8.2″

19h

+22° 09.9′

(1196)

(65)

Asterism

3.6

90′

19h 26.2m

+20° 06′

1220

19h

30.6m

+20° 16′

1220

19h 35.8m

+25° 10′

1196

36.5m

+25° 00′

1196

(64)

45.6m

+27° 57′

(1172)

(64)

NGC 6802

Open cluster

8.8

5.0′

Stock 1

Open cluster

5.2

34′ core, 80′ halo

Σ2548
LDN 810

28.7m

Dec.

19h

Double star
Dark nebula

23.22m

8.5, 9.9

9.4″

19h

18′ × 9′

19h

Angular sizes and separations are from recent catalogs. Visually, an object's size is often smaller than the cataloged value and varies according to the aperture and
magnification of the viewing instrument. Right ascension and declination are for equinox 2000.0. The columns headed MSA and PSA give the appropriate chart
numbers in the Millennium Star Atlas and Sky & Telescope's Pocket Sky Atlas, respectively. Chart numbers in parentheses indicate that the object is not plotted.

S E P TE M B E R 2 019 * SK Y & TELESCOPE

T. A . RECTOR (UNIV ERSIT Y OF A L ASK A A NCHOR AG E ) /
H. SCHWEIK ER ( WIY N A ND NOAO / AUR A / NSF )

Object

Sky & Telescope - September 2019

Table of Contents for the Digital Edition of Sky & Telescope - September 2019