Sky & Telescope - December 2022 - 58

DECEMBER 2022 OBSERVING
Going Deep
N
COSMIC PADDLES With my 6-inch reflector
the paddles extend the Andromeda Galaxy
from its regular visual length of 3° to 5°. Photometrically,
the galaxy measures some 3.2°
degrees across. Of Herschel's 52 nebulous regions
that he tabulated in his 1811 article, I've
identified numbers 7, 8, 9, and 10 as clouds of
Andromeda, which extend from M110 to Beta
(β) Andromedae (labeled). Region number 8 is
probably the bright cirrus left of the star.
view - the clouds break up into puffs.
Why? It's likely that the darker areas
between the puffs are large enough
in apparent size that the 30-inch can
detect them. I estimate them to be
roughly 5° to 10° in apparent length
in the eyepiece.
I also note a fainter and thinner
β
the 30-inch it reminds me of what the
Andromeda Galaxy looked like with
the 4-inch telescope that my parents
bought me for a grade-school science
project on the Moon.
The nearly face-on M33, the smallest
spiral in our Local Group of galaxies, is
a notorious test of sky conditions and
of our eyes. But unlike the Andromeda
Galaxy, in dark skies M33 becomes
breathtaking as aperture increases.
Andromeda's Nebulosities
All those years ago with my
4-inch I felt transported to
the stars from my Portland,
Oregon, backyard (which I
darkened by simply switching
off the porch light!). I
first saw the Andromeda
Galaxy as an oval with a
starlike nucleus that, when I
looked directly at it, turned
fuzzy. This " is it fuzzy? " versus
" is it starlike? " dichotomy
persists even with my
large scopes 55 years later.
To observe the Andromγ
M110
ν
M31
2
3
4
5
6
7
TRIANGULUM
ANDROMEDA
M32
μ
β
+35°
π
eda
Galaxy's clouds, you'll
need transparent skies (a
reading of at least 21 on a
Sky Quality Meter, or Bortle
M33
α
1h 30m
58 DECEMBER 2022 * SKY & TELESCOPE
τ
PISCES
1h 00m
δ
+30°
ε
0h 30m
3); use lower-power, wide-angle eyepieces
yielding a maximum exit pupil; and
then look for faintly indistinct, glowing
regions. Shake the nebulosity loose by
moving your eye about the field every
few seconds and by gently jiggling the
scope occasionally.
In my 6-inch, I see the clouds as
broad regions, while in my 25-inch
f/2.6 (1.1° field) they appear as continuous
streaks and daggers of similar
sizes. But with my 30-inch, a wonderful
new realm of detail comes into
third spiral arm just outside the more
dramatic second arm, as I've drawn in
my sketch on page 57. In particular, the
spiral arms display beautiful daggers and
frills along their edges that I'd not seen
before in my smaller scopes. These are
difficult to pin down - it's like accounting
for individual crests in the surf.
Unexpectedly, I also find that I can trace
the spiral arms in close to the nucleus.
Maybe what stands out most are
the hues and colors. Patches near the
nucleus look yellowish, while the surrounding
Milky Way stars fill in the field
of view in myriad colors. This all makes
me wonder what views a larger, widefield,
very fast telescope of 40 inches or
greater might provide.
If at first you don't succeed, keep trying.
The initial view is always
the most difficult to feel confident
in. Subsequent views
build on visual memory, often
making objects easier to see
and adding more detail -
sometimes even making them
accessible in smaller scopes.
+40°
Observing and
Sketching Tips
I use three exit pupils in
my wide-angle viewing: a
slightly oversized pupil (8
mm) that's surprisingly
effective; a pupil matched
to my eye (6.7 mm) that
reveals more detail, but at
the cost of reduced field size;
Star magnitudes
Sky & Telescope - December 2022

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