54 ASTRONOMY • FEBRUARY 2018
faintest wisp
through my 8-inch
at 54x. Bordering
M78 to the south-
west are two more
clouds, NGC 2064
and NGC 2067. I
can’t make them
out in my 8- or
10-inch scopes
under suburban
skies, but my
18-inch does t he
trick. Can you spot
all four?
Near the three
faint stars that
mark Orion’s tiny
triangular head is
NGC 2022, one of two plan-
etary nebulae in Orion within
the reach of amateur tele-
scopes. My 8-inch displays an
11th-magnitude sphere with a
bluish hue.
The sphere turns slightly
oval when magnified at about
200x, with the major axis ori-
ented northeast-southwest. Its
central star shines at only 15th
magnitude, keeping it beyond
most backyard scopes.
Orion’s second planetary lies
in the constellation’s sparse
northwest corner. Jonckheere
320 is a magnitude fainter than
NGC 2022. That’s bright
enough to be seen through an
8-inch telescope trapped under
the veil of suburban light pollu-
tion. But there are so many
stars in the same field that pick-
ing out the planetary is a tough
job. J320 measures only 26" by
14" across, and indeed is easy to
confuse for a close-set double
star if viewed at low power, as
French astronomer Robert
Jonckheere likely did during his
initial discovery in 1916.
To find it, you may need to
“f lash” the planetary, if you’ll
pardon the phrase, by moving a
narrowband or Oxygen-III fil-
ter back and forth between your
eye and eyepiece. (Be sure to
hold it securely.) Doing so will
suppress the field stars, but not
the planetary. The culprit will
have no choice but to surrender.
Several more open clustersgroup of about fifty
10th-magnitude and
fainter stars spread
over an 11' area. My
4-inch refractor
shows about a
dozen stars, with
a few appearing
noticeably brighter
than the rest.
Two degrees far-
ther west along the
celestial equator is
another clump of
nebulosity, M78.
Pierre Méchain dis-
covered this 6'-by-8'
patch of light in- Half a cen-
tury later, Smyth described it
as “two stars in a very wispy
nebula” in his 1844 book A
Cycle of Celestial Objects. This
is close to the visual impres-
sion through modern-day
amateur telescopes.
Its appearance through my
8-inch ref lector reminds me of
a small comet with two 10th-
magnitude nuclei and a small,
broad “tail.” Those two stars,
HD 38563A and HD 38563B,
illuminate the dust in M78 to
create a ref lection nebula — the
brightest one in the sky.
Look carefully, and you
might also see NGC 2071 just
northeast of M78. It’s only the
The Horsehead is one of the
most challenging objects in the
entire sky to see visually. Many
people try, but few succeed.
Hard as it is to believe, I have
seen the Horsehead through
11x80 bi nocu la rs f rom t he
Winter Star Party in the Florida
Keys. But I routinely miss it with
my 18-inch ref lector from my
suburban Long Island backyard.
Here are some tips for find-
ing it: First, you need an ideal
observing site. And be sure to
wait until Orion is due south,
when it is highest above the
horizon.
Next, use technology.
Hydrogen-beta eyepiece filters
are sometimes jokingly called
“Horsehead filters” because
they can increase image con-
trast just enough to pull it out.
Finally, be sure to move
Alnitak just beyond the north-
ern edge of the field, while
keeping Sigma off the western
side. As a hint to show that
you’re nearing your target, look
for a close-set pair of 8th- and
9th-magnitude stars near the
leading edge of IC 434. They
are just west of the Horsehead.
Good luck!
About a degree west of 60
Orionis is a fine open cluster
that many observers overlook.
NGC 2112 is a moderately richRight: Orion’s
brightest star,
Rigel, appears
as a bright sun
with a tiny, faint
companion in this
sketch made with
an 8-inch reflector
at 240x. JEREMY PEREZ
Below: Open
cluster NGC 2112
is one of Orion’s
overlooked deep-
sky treasures.
MARTIN C. GERMANO