Sky and Telescope - March 2016 - 30

Cosmic Coils
14h

13h κ

12h

11h

M82

10h

α
κ

M101

NGC 3628

Mizar

M108

M109

M51

C A N E S V E N A T I C I M106
M63

2
3
4
5
6

+50°

M40

M97

3631

4449

+40°

3184

LEO
MINOR

a pair of 10.9-magnitude sparks with a
9″ separation. Immediately to the south
shines the 2.1″ double Σ1386, which consists of matched 9.5-magnitude suns.
NGC 3184 is conveniently located near
Mu (μ) and Lambda (λ) Ursa Majoris, the
middle of three naked-eye pairs of stars
poetically known as "the Three Leaps of
the Gazelle." Bill Ferris, with his 18-inch
at high altitude near Flagstaﬀ, Arizona,
detected three of NGC 3184's spiral
arms. My 16-inch, at 229× in only fair to

UWE GLAHN

BLUE HEAT Left: Visually, you won't see any color in NGC 3184, but deep-sky images show the
blue of the young, hot stars populating its spiral arms. Right: Uwe Glahn picked up the galactic
nucleus with its neighboring 14th-magnitude star with his 16-inch reﬂector at 257×. Look for the
11th-magnitude star at the edge of the northern arm.

March 2016 sky & telescope

IN THE CORNER M66 holds down one
corner of the well-known galaxy group, the Leo
Triplet. While you're in the neighborhood, look
west for the intermediate spiral M65.

NGC 3184

MICHELE BRUSA

M66

North of the galactic center, beyond a
dark band, I detected a vague 1.5′ section
of arm. This short arc of arm was the
most diﬃcult segment to spot, while the
eastern arm appeared widest.
Double stars are always the best objects
to use to obtain a sharp focus when looking at fuzzy objects like galaxies, and a
couple of good candidates shine close to
M81. The second-brightest star in the ﬁeld,
located south-southwest of the galactic
center, is the binary Σ1387 (Struve 1387),

M65

2841

URSA MAJOR

M94

+60°

Star magnitudes

M81

good seeing, showed a relatively large,
bright center with a nucleus and a 14thmagnitude star 1′ northeast. The galaxy
appeared darker beyond the core, but I
detected an outer ring, shining brightest
in the south and southeast, that resembled a view of M51 in an 8-inch scope. An
11th-magnitude star lies on the northern
edge of the galaxy. Nice, but I would like a
look with bigger glass.
M66, the dominant member of the
M66
Trio in Leo, sports a prominent bar, and
at 140×, I detected the bright, elongated
core lying diagonally across the elongated
galaxy. I pulled out two spiral arms with
the 16-inch at 261×. The longer arm
extends well to the south, almost as far as
the main body of the galaxy is long. I also
spotted the bright root of the second arm,
known colloquially as the Crab's Claw.
Back in Ursa Major, NGC 3631 at 203×
in the 16-inch shows a large, amorphous
halo with some mottling. There's a very
faint star upon this face-on spiral. The
brightest star in the adjacent scalene
triangle is a double, Σ1520 (magnitudes
6.6 and 7.9 at 12.7″). The primary appears
yellowish. Sissy Haas describes the secondary as "a little white star," but NSOG
oﬀers "yellowish and pale blue."
On my third attempt to discern NGC
3631's arms with this scope, I enjoyed a
night of superb transparency and very
good seeing. After cooling my mirror for

JEFFREY WEISS

15h

Sky and Telescope - March 2016

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