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skyandtelescope.com • NOVEMBER 2019 55
visible through the 130-mm scope.
It did make an appearance with my
10-inch refl ector at 299×, and it showed
better at 374× even though atmospheric
turbulence made the stars look furry at
that power.
Let’s return to the star 18′ south of
Lassell 1 and look for a slightly dimmer,
orange star 16′ to its southeast. The
planetary nebula Abell 78 sits midway
between these stars. While I was star-
hopping my way to Abell 78 with my
130-mm scope at 102×, it conveniently
popped into view by a fortunate chance
of averted vision. Only the central star
was evident when looking straight at
the nebula. With a slightly higher mag-
nifi cation, I detected a fairly large but
vague presence, like a fl eeting memory
of moonlight. This fragile apparition is
attended by a faint star off its east-
northeastern edge and a little bunch
of stars near its northwestern edge. A
narrowband nebula fi lter makes the
planetary a bit clearer, but an O III fi lter
gives a displeasingly dim view in a scope
this small. The 10-inch scope at 166×
reveals a slightly darker area around the
central star.
Images of Abell 78 show a knotty,
east-west ring approximately 1.5′ × 0.9′
within a 2′ faint and slightly oval glow
tilted northwest. The planetary’s outer
shell is composed mostly of hydrogen
that once made up the outer layers ofits progenitor star. The knotty ring is
hydrogen-defi cient and shines largely
by the light of doubly ionized oxygen
(O III). It contains large amounts of
helium forged in the fi res of its parent
star and dredged up to the surface along
with heavier elements by a late fl ash of
energy from fusion in the star’s helium
shell. The star, formerly on its way to
white dwarfhood, was temporarily
reborn as a red giant that entered a sec-
ond planetary nebula phase and ejected
its hydrogen-depleted envelope into the
previous nebular shroud.
Cygnus seldom comes to mind
when we think of galaxies, but let’s
take a peek at NGC 7013, located 2.1°
west-southwest of Zeta Cygni. It’s the
second-brightest galaxy in Cygnus,
topped only by NGC 6946, which
straddles the Cygnus-Cepheus border
far to the north.
NGC 7013 is merely a faint, elon-
gated glow through my 105-mm refrac-Egg NebulaBaby DumbbellAbell 7870137063Lassell 152¡hi61copm707274764977CYGNUS+40°+38°+36°+34°+32°+30°21 h 30 m 21 h 20 m 21 h 10 m 21 h 00 m 20 h 50 m 20 h 40 mVeil Nebulator at 47×, but the view is much nicer at
87 ×. The galaxy appears about 2½′ long,
tipped north-northwest, and grows
considerably brighter toward the center.
A 10th-magnitude star dances on its
northern tip, while a faint star guards
its western fl ank.
Through my 10-inch refl ector at
213 ×, NGC 7013 covers 3¾′ × 1¼′ with
a 1½′-long core and a bright nucleus.
The core runs nearly north-south and
shows subtle structure. I think it looks
like a fat, squashed, indistinct Z, but
images indicate that my eye is blending
parts of the galaxy’s interior ring and its
nucleus. Can anyone with a large tele-
scope discern this circumnuclear ring?
Now sweep 3.0° east from Lambda
(λ) Cygni to the protoplanetary Egg
Nebula (PK 80-6 1). Such nebulae are
rare because they live for an astronomi-
cally brief time. When an aging star
a little more massive than our Sun
exhausts its hydrogen fuel, it sheds itsqThe components of Lassell 1 are labeled
here by their Washington Double Star Catalog
designations. The fi eld is 15′ wide, and the
“false double” described by the author is in the
upper-left corner.FC
GEA
DB