Sky and Telescope - July 2018 - 71
p DUMBBELL, HOURGLASS, APPLE CORE And finally we get to
the inverted version of my original sketch, giving a better sense of the
eyepiece view through my 28-inch scope from a dark site. There are
too many field stars to plot, but imagine about five times more than
you see here and you'll get the idea of what a beautiful scene this is in
a large telescope, and how they contribute to the 3D effect. Next time
you observe this "most extraordinary object" decide for yourself what
shape you see.
u NESTED NEBULOSITIES In addition to the brighter, inner nebulosity,
M27 also displays a fainter, more extended nebula. Can you see it?
SK E TCH: HOWA RD BA NICH; NEBULOSIT Y: M ASIL IM AGING TE A M
I've only seen the Dumbbell as various shades of grey through
the eyepiece. But a few people have reported a greenish hue
at very low magniﬁcations, so give it a shot with your lowestpower eyepiece. Look directly at M27 to give yourself the best
chance of seeing color.
A 3D Illusion
Wonderfully, the Dumbbell Nebula can sometimes seem to
ﬂoat in 3-dimensional space. This is an illusion, of course,
but it can be a compelling sight in the eyepiece nonetheless. I
see this effect best without a nebula ﬁ lter, because the more
ﬁeld stars are visible, the more pronounced the false 3D.
Sometimes boosting the magniﬁcation helps enhance this
impression. And when the illusory 3D effect is strong, it's
fun to spin M27 in my imagination and visualize its headon ring shape.
Taking all this together, on a good night at a dark site the
Dumbbell is stunning in my 28-inch scope, and it barely
matters what magniﬁcation is used. I like it best when it ﬁlls
about half the ﬁeld of view, though - a bright, subtly lumpy,
and softly glowing dumbbell-rectangle-oval, with its parent
white dwarf star at its center, all ﬂoating within a beautiful
star ﬁeld. A most extraordinary object indeed.
¢ Contributing Editor HOWARD BANICH recently moved from
Portland, Oregon, to the much darker but still light-polluted
skies of Sandy, Oregon. Reach him at email@example.com.
s k y a n d t e l e s c o p e . c o m * J U LY 2 0 1 8