Sky & Telescope - December 2021 - 62

Imaging Targets
A BIT OF EVERYTHING The combination of emission, reflection, and
dark nebulosity in M78 makes it challenging to image but rewarding
when you pull it off successfully.
because it contains structures of so many different colors
and brightnesses. But these attributes make it a challenging
target to process.
Moving east-northeast about 12° to Monoceros you'll
come to NGC 2237, NGC 2238, and NGC 2239, which
together make the Rosette Nebula, a large emission nebula
complex roughly 1½° in diameter (see image on page 27).
Standing out in stark contrast along its north and west sections
are a meandering series of dark knots of dust. The most
prominent of these appears as a jagged, three-vane structure
almost due north. Each of these dark clumps of dust is slowly
evaporating due to hot stellar winds emanating from the
young stars of open cluster NGC 2244 in the center of the
nebula. The Rosette looks great when photographed through
most any telescope - imagers with wide-field instruments
can frame the entire complex, while those using large scopes
can focus their attention on the complex strands of dust.
Fall-Winter Dark Nebulae
Object
LDN 1235
B150
NGC 7023
LDN 1174
LDN 1173
LDN 1172
LDN 1170
IC 1396
vdB 142
B33
NGC 2024
M78
NGC 2237-39
Type
Dark
Dark
Reflection
Dark
Dark
Dark
Dark
Emission
Dark /
Reflection
Dark
Dark /
Reflection
Emission /
Reflection
Emission
7′ × 6′
80′ × 60′
05h 46.7m +00° 03′
06h 32.3m +05° 03
Angular sizes are from recent catalogs. Right ascension and declination are
for equinox 2000.0.
Size
100′ × 40′
60′ × 3′
18′
37′
5′
6.8′
32′
1′
RA
22h 15m
Dec.
+73° 25′
20h 50.6m +60° 18′
21h 00.5m +68° 10′
21h 02.6m +68° 12′
21h 04.7m +67° 42′
21h 02.7m +67° 42′
21h 01.7m +67° 37′
2.8° × 2.3° 21h 39.1m +57° 30′
21h 37.1m +57° 29′
6′ × 4′
30′
05h 40.9m
05h 41.9m
-02° 28′
-01° 51′
Lazy Summer Nights
The summer Milky Way features some of the most majestic
dark nebulae found in the sky. Most obvious is the massive
complex of dust found in Ophiuchus, northwest of the
galactic center. Here lies a sprawling collection of opaque dust
and gas roughly 10° in circumference known collectively as
the Dark Horse Nebula. The Dark Horse is most recognizable
as a walking horse with its head bowed low if you present
the image with east at the top. The horse doesn't have an
official designation, but individual parts of it do. Its hind legs
are made up of B78, also known as the Pipe Nebula (a large,
7°-wide nebula itself), and B72, the S-shaped Snake Nebula
found within the horse's torso. You can record this entire
collection of nebulae with a full-frame camera and lens of
about 100-mm focal length, though smaller components like
B78 require a field of at least 8° to adequately frame both the
Pipe's stem and bowl. The Snake Nebula is framed best with
about a 1° field of view.
Moving about 9° east into Sagittarius, we find M20, the
Trifid Nebula. While we usually think of the Trifid as an
emission and reflection nebula complex, it owes its nickname
to dark nebula B85, appearing as a triad of dusty gashes
dividing up the emission component. Messier 20 is a colorful
target with many small-scale features that beckon imagers
with large telescopes, but it also looks great in wide-field
astrographs, particularly when framed to include its popular
neighbor M8, the Lagoon Nebula, just 11
/3° south-southeast.
Following the Milky Way north into Aquila we come to
another silhouetted molecular cloud with a familiar appearance.
With a little imagination, the two dark nebulae B142
and B143 appear like an interstellar letter E. Use a field of at
least 1.5° to frame it comfortably and be sure to orient your
camera so that its long axis is directed north to south. Only
2° west-northwest is LDN 673, a fascinating dark nebula
62 DECEMBER 2021 * SKY & TELESCOPE
Sky & Telescope - December 2021

Table of Contents for the Digital Edition of Sky & Telescope - December 2021
