Astronomy

56 ASTRONOMY • MAY 2018

discover and share. Skilled deep-sky
observers are renowned for seeing what
used to be deemed impossible, and I have
faith in them.
Observers can easily overlook Leo’s dis-
crete southern extension, which contains
some interesting galaxies. Chief among
them is NGC 3521, one of the most
neglected bright galaxies in the night sky.
This 9th-magnitude marvel rivals many of
the Messier galaxies. Through a 4-inch
scope, this oblique spiral spans 12' by 6.5',
is oriented northwest-southeast, and
appears cometlike — similar to an ellipse
within an ellipse. It is classified as a floc-
culent spiral (like NGC 2841 in Ursa
Major) with extensive debris shells that
surround the galaxy’s disk like a toy in a
bubble bath. This is yet another stunning
example of a galactic cannibal, where the
sloppy remains of several long-deceased
satellite galaxies still surround a voracious
spiral. While much of this drama is invis-
ible to the eye, I do wonder if the brightest
patch of the slaughter — just northeast of
the nucleus — can be spied in large ama-
teur telescopes.

Rings and things
Leo’s most famous gaggle of galaxies is
undoubtedly the Leo Triplet, consisting of

two 9th-magnitude spirals, M65 and M66,

joined by the slightly fainter edge-on spiral

NGC 3628 (the Hamburger Galaxy).

Located about halfway between Theta (θ)

and Iota (ι) Leonis in the big cat’s thigh,

this winning trio travels as a pack at a dis-

tance of about 30 million light-years. All

measure about 10' in length, can be spied

even in 10x50 binoculars under a dark sky,

and telescopically display the deforming

effects of tidal warping.

Telescopes as small as 4 inches can

reveal the “broken arms” of M65 and M66,

but the most amazing and concealed fea-

ture of the group is a striking tidal “plume”

trailing off NGC 3628. This extragalactic

umbilical cord of star-forming regions

extends some 2 ̊ east of NGC 3628’s north-

eastern rim before arcing slightly to the

north, making the galaxy appear like an

old westbound ocean liner trailing smoke.

Lenses as small as 200 millimeters have

been able to capture this tail. The question

is: Can it be seen visually? And if so, at

what aperture and magnification?

Return your telescope to Regulus. Now

Above: An obliquely oriented spiral, NGC 3521
is one of the most overlooked bright galaxies
in the sky. A small scope shows it as a beautiful
cloud of light. KEN CRAWFORD