Sky and Telescope - November 2015 - 41

OBSERVING

Northern Hemisphere's Sky

Fred Schaaf welcomes your
comments at fschaaf@aol.com.

Fred Schaaf

In Praise of Pisces
A dim zodiac constellation oﬀers some surprising attractions.
A vast section of the November evening sky is ﬁ lled
with dim water-related constellations. The faintest of
them all is Pisces the Fish.
Even so, I write in praise of Pisces. I'm going to
explain why even its dimness can be part of the pleasure
we ﬁnd in observing it. But there's much else of mental
interest to ponder, and visual interest to observe, in this
constellation of the (two) Fish.
Reclaiming the heritage of naked-eye Pisces. How
easy is it to see anything in Pisces with the naked eye if
you have a heavily light-polluted sky? Not very. The only
two stars brighter than magnitude 4.0 in the constellation are Eta (η) and Gamma (γ) Piscium (magnitude 3.6
and 3.7, respectively).
Fortunately, that's not all there is to the story of
observing Pisces. For instance, there are about 10 stars
(one is a variable) between magnitude 4.0 and 4.5 in the
constellation - and, of course, many more of 5th and
6th magnitude. This number begins to suggest how
beautiful it is to experience with the naked eye a constellation like Pisces in a truly dark sky - the environment
in which it was originally seen and created.
When you see Pisces in a dark sky you can start to
reconnect with earlier skygazers and all of the wealth of
observation, legend, and cultural tradition they found in
the faint ﬁsh. This is not only one of the constellations of
the zodiac, it's the one which today contains the vernal
equinox point in the heavens. Think of the history and
tradition we can regain in Pisces when we travel to a
dark sky or succeed in reducing light pollution somewhere. Binoculars can help show the stars of Pisces if
your sky is too bright, of course. But there's no replacement for the wide and natural naked-eye view.
Tracing the two ﬁsh and cord. First, trace out
the Circlet asterism of stars that forms the head of the
western ﬁsh of Pisces, right under the much brighter
Great Square of Pegasus. Then scan east until you ﬁnd
a southeast-curving line of seven stars that begins just
before the 1 h line of RA and ends just after the 2h line.
Less than 2°° south of the second star in the line, Epsilon
(ε) Piscium, is a special treasure this month: the magnitude-5.7 planet Uranus. The seventh star along the curve
is magnitude-4.3 Alpha (α) Piscium. It's most often
called Alrescha or Risha, which means "the rope," hearkening back to an old legend in which the Great Square

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of Pegasus was a bucket attached to a rope. The star has
also been called Okda, "the knot" in the cord connecting
the two ﬁsh of Pisces.
You'll need quite dark skies to follow the line of the
northern ﬁsh from Alrescha up to Andromeda. The
triangular head of the northern ﬁsh is not far from
the great but sometimes elusive M33, the Triangulum
Galaxy. In the body of the northern ﬁsh shines Eta
Piscium, which can be found by running a line from
magnitude-2.0 Alpha Arietis (Hamal) through magnitude-2.6 Beta (β) Arietis (Sheratan) and extending the
short line several times its length. Why would you want
to ﬁnd Eta Piscium? For one thing, it's a guide to Pisces'
only Messier object: M74, just 1½° north-northeast of
the star. M74, a lovely but low-surface-brightness spiral
galaxy, is the ﬁrst object everyone must ﬁnd in March
Messier marathons.
Mystery-hued doubles of the double ﬁsh. We can't
pretend that Pisces is rich with bright galaxies, clusters,
or nebulae. It very deﬁnitely isn't. But an overlooked type
of deep-sky wonder in the underappreciated ﬁsh is its
marvelous double stars. If you don't use too much aperture, you may be able to detect their tints. Do you see a
hint of green in the brighter component of tight Alrescha (magnitudes 4.2, 5.1)? Wide lovely duos in Pisces
include Psi1 (ψ1) Piscium and Zeta (ζ) Piscium. Fairly
close pairs are 55 and 65 Piscium. And if you're looking
for color, don't forget the very red 5th-magnitude variable
star TX Piscium, on the edge of the Circlet. ✦
Sk yandTelescope.com November 2015

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Sky and Telescope - November 2015

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