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OBSERVING
Deep-Sky Wonders
Star magnitudes
Star magnitudes
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Heavens Within Themselves
Five adjacent galaxies exhibit amazingly varied structures.
The vast sun clusters’ gather’d blaze,
World-isles in lonely skies,
Whole heavens within themselves, amaze
Our brief humanities.
— Alfred, Lord Tennyson,
The Charge Of The Heavy Brigade At Balaclava
Although I’ve been writing monthly columns for Sky
& Telescope for a dozen years, there are two objects from
Charles Messier’s famous catalog that I’ve never touched
upon. This is the perfect time of year to correct that oversight
by featuring these neglected galaxies, M88 and M99
in Coma Berenices.
M88 is one of the brightest spiral galaxies in the
Virgo Cluster, which is centered about 54 million lightyears
away from us and contains at least 1,300 members.
M88 is a Seyfert galaxy, defi ned by a brilliant nucleus of
variable light intensity coupled with a spectrum indicating
that it’s powered by a supermassive object (probably a
black hole) at the heart of the galaxy. Seyfert galaxies are
named for the American astronomer Carl Keenan Seyfert
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24
25 M85
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COMA BERENICES M100
M88 M98
M91 6
M90 M86
M99
95
M59
M84
M60
M89 M87
M58 VIRGO LEO
12 M49
h 30m 13h 00m +15°
+10°
12h 00m +15°
+14°
M91
4571
56 May 2012 sky & telescope
12 h 35 m
COMA BERENICES
4516
M88
IC 3476
12 h 30 m
4474
4468
4459
who, in the 1940s, found a number of galaxies presenting
these features.
M88 is located 2.9° south-southwest of 25 Comae, and
it’s yours for the taking through almost any telescope in
a moderately dark sky. Admiral William H. Smyth found
M88 quite charming through his 6-inch refractor. In his
1844 Bedford Catalogue, Smyth writes: “A long elliptical
nebula, on the outer side of Virgo’s left wing. It is palewhite
in colour, and trends in a line bearing np [north
preceding, or northwest] and sf [south following, or southeast];
and with its attendant stars, forms a pretty pageant.”
M88 and 25 Comae share the fi eld of view through
15×45 image-stabilized binoculars. From my semirural
home, the galaxy is a faint oval with a dim star dangling
from its southeastern end. M88 is easily visible
and elongated through my 105-mm refractor at 28×. It
runs southeast-northwest, and the star that was visible
through binoculars now looks fuzzy. At 87× this unsharp
star becomes a wide, unequal pair that makes a skinny
triangle with a very dim star to the east. Closer to M88,
another faint sun perches north of the galaxy’s northwest-
Messier 88 is one the sky’s
brightest Seyfert galaxies.
Like all Seyferts, it has a tiny,
brilliant nucleus with exotic
emission lines.
JIM QUINN / ADAM BLOCK / NOAO / AURA / NSF