Sky News - CA (2019-11 & 2019-12)

NOVEMBER/DECEMBER 2019 •SKYNEWS 27

O

peN ClUsters are a binocular
observer’s best friend. sure, there
are impressive nebulas, galaxies
and globulars too, but rich collections of
pinpoint stars are ideally suited to the wide-
field views binos excel at providing. And if
you need proof, look no further than the
region between perseus and Cassiopeia.
there, you’ll find the famed double
Cluster, plus a nearby bonus object
(more about that later).
the double Cluster’s side-
by-side components are ori-
ented east-west and named
NgC884 and NgC869,
respectively. despite the
separate designations, it’s
impossible not to think of
them as a single sight. how-
ever, doing so slightly under-
sells their individual splendour
—each cluster would be regarded
as a showpiece were the duo split up and
redistributed to different constellations. Un -
der a dark sky, my 15×45 image-stabilized
binoculars show the double Cluster as two
similarly wonderful, jewel-like concentra-
tions of starlight. simply beautiful. but the
perseus pair remains impressive even when
enjoyed with smaller binoculars amid less
favour able conditions.
since the double Cluster is so visually
appealing, you’re probably wondering why
it didn’t make the cut for inclusion in the
famous Messier catalogue. good question!
Charles Messier wasn’t particularly inter-
ested in deep-sky sights; rather, his quarry
was comets. his 18th-century catalogue is
a list of 110 mostly fuzzy objects that po-
tentially could be mistaken for comets. he
was certainly aware of the double Cluster’s
existence, so why didn’t this double fuzzy
fit the bill? I’ve read a number of theories
on the subject (most notably by stephen
James o’Meara, who devotes five pages to

the question in his book The Caldwell

Objects) but remain unconvinced that any

of them are correct. this long-standing

Messier mystery is something to ponder

the next time you train your binoculars on

the splendid twosome.

Now, about that bonus object I men-

tioned earlier. we have a third cluster to

consider: stock 2. (Messier skipped

this one too, but given its ap -

pearance, the omission is

understandable.) Also

known as the Muscleman Cluster, stock 2

is a sparse smattering of stars spanning

more than one degree and seemingly teth-

ered to the double Cluster by a gently curv-

ing row of sixth- and seventh-magnitude

suns. because all three clusters lie within

two degrees of one another, they can be ap-

preciated in a single binocular field of view.

And despite stock 2’s brawny nickname,

you’ll need reasonably dark conditions to

see it—most of its stars glow feebly around

magnitude 9. ✦

THE BINOCULAR SKY by gary Seronik

double cluSter, triple fun

e zone between perseus and Cassiopeia is home to several splendid

binocular-friendly deep-sky delights

5° binocular

ield of view

double cluster

Stock 2

THREE FOR THE PRICE OF ONEthe famed perseus double cluster is one

of the binocular sky’s true showpieces. it’s made all the more appealing by

the presence of a third cluster, Stock 2.PHOTO BY GARY SERONIK

CASSIOPEIA

AN

DRO MEDA

M31

TRIANG

ULUM

PERSEUS