Sky & Telescope - December 2021 - 61

ALL IMAGES COURTESY OF THE AUTHOR
the cloud makes up the shark's " snout " roughly 10″ northeast
of 6th magnitude HD 211300, the shark's " eye. " The
predator's body appears in long exposures as brownish dust
trailing off to the west. Adding to the shark's anatomy are
two reflection nebulae, vdB 149 and vdB 150, which some
interpret as representing the dorsal and pectoral fins, respectively.
This collection of objects fits cozily in a 3½° field with
a little room to spare for creative framing.
Another interesting bit of dust lies 1½° south-southeast of
vdB 142
IC 1396
Eta (η) Cephei: B150, often referred to as the Seahorse Nebula.
Brownish dust throughout the field surrounds the denser
material that produces the 1° seahorse shape aligned roughly
east-west and terminating at 8.5-magnitude HD 198300. A
wide-field telescope and camera combination producing at
least a 1½° field is necessary to frame this target.
Returning to Alfirk, aim 31
/3° southwest for NGC 7023,
the Iris Nebula. This complex structure contains reflection,
emission, and dark nebulae each having its own designation.
Just 6′ northeast of the reflection component is the prominent
dust of LDN 1174, while ½° to the south is a group consisting
of LDN 1173, LDN 1172, and LDN 1170. These are just
a few of the many dusty structures revealed in long exposures
of this region (more can be found in the August issue, p. 18).
Before moving on from Cepheus, I can't resist slewing
slightly more than 1° southwest from 4th-magnitude Mu
(μ) Cephei, the Garnet Star. That's where the large, faint
emission nebula IC 1396 resides. This sprawling object covers
a 2°-wide, roughly circular patch of sky and is riddled
with thick clumps of dark nebulosity. The best known is
vdB 142, the Elephant's Trunk Nebula, located just west of
the center of IC 1396. The Elephant's Trunk also contains a
small, bluish reflection component, which landed it on van
den Bergh's catalog of reflection nebulae. The entire IC 1396
complex is an excellent target for large and small telescopes
alike; small, wide-field instruments with a 2½° field of view
will frame the entire nebula, while large telescopes are better
suited for close-ups of vdB 142 and other nearby silhouetted
knots of dust.
Skipping southeast over to Orion, you'll find some of the
best-known dark nebulae of the winter Milky Way. Orion
houses such a treasure trove of glittering deep-sky objects that
perhaps the darker features have escaped your notice.
The most striking of these for imagers is B33, the famous
Horsehead Nebula, located ½° south-southeast of Alnitak, the
easternmost star of Orion's Belt. This distinct pillar of cosmic
dust billows in front of the glowing nebulosity of IC 404. Just
15′ east-northeast of Alnitak lies NGC 2024, the Flame Nebula,
with its back-illuminated dust lanes giving the appearance
of a match that's just been struck. Both NGC 2024 and B33
comfortably fit within the same 1° field. These two objects are
among the most frequently imaged dark nebulae in the winter
sky (see page 25).
Found 2½° northeast of Alnitak are the dark tendrils
winding through reflection nebula M78. Aside from its
network of opaque dust, I've always found M78 interesting
LDN 1174
NGC 7023
LDN 1172
LDN 1170
LDN 1173
KNOTS AND TRUNKS Top: The large emission nebula IC 1396 in
Cepheus hosts several dark components. Particularly interesting for
imagers with large scopes is vdB 142, seen at right, which also contains
a small, bluish reflection nebula.
EXOTIC FLOWER Above: Composition is important when attempting
to include as much of the dust surrounding the Iris Nebula (NGC 7023)
as possible in the frame. Orient the long axis of your camera north to
south and place the bright reflection nebulosity towards the top of the
frame in order to include dark nebulae LDN 1173, 1172, and 1170.
sk yand tele scope .o r g * DECEMBER 2021 61
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Sky & Telescope - December 2021

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