Be a considerate
neighbor: Shield all your outside lights downward (or turn them
off completely) and enjoy the beautiful, starry night sky.
December 2005 night sky
THE SIGN OF THE FISH
In the sky this month is Pisces the fish. The constellation is quite
dim; the brightest star, nu Piscium, is only magnitude 3.6. Alpha
Piscium is called Alrisha, “the knot.” Alrisha is the
star that ties the two fish together. Pisces is the twelfth sign
of the zodiac.
The Greeks always have an interesting story to tell about the
stars: Typhon was born from Gaia (Mother Earth) and Tartarus. This
was Gaia's youngest offspring, but by far the deadliest and the
largest monster ever conceived. Its thighs were gigantic coiled
serpents; its arms could spread across the heavens. Its head was
in the shape of an ass’s head and could touch the stars. When
it took flight, its wings blotted out the sun. When it opened its
mouth, burning boulders poured forth.
Typhon was so frightful even the gods of Olympus refused to fight
it, fleeing instead to Egypt when Typhon attacked their mountain
home. Each god disguised itself into an animal: Zeus transformed
himself into a ram, Dionysus a goat, and so on. Aphrodite and Eros
both disguised themselves as fish and swam up the Nile to escape
Eventually, Typhon was defeated, thanks in large part to the brave
and level-headed Athene, who convinced Zeus to take up his thunderbolts
and make battle. Typhon actually captured Zeus and placed him in
a cave, but Hermes and Pan were able to free him. Zeus then took
the battle to Typhon, chasing him to Sicily. There Zeus threw Mount
Aetna at the monster, finally subduing it. But under the earth,
the buried monster still spews up fire and boulders every so often.
Aphrodite and Eros, who escaped the monster's wrath, were given
their fish-like images in the heavens, thus commemorating the time
Typhon nearly overran Olympus.
There are a few fine binaries, an interesting variable, and one
Messier object that is a beautiful face-on spiral; unfortunately,
it is very faint and a challenge for smaller telescopes.
• Alpha Piscium is a binary where the stars orbit each
other every 933 years. The two stars are magnitude 4.3 and 5.2.
Under dark skies, binoculars may show this pair.
• Zeta Piscium is a fine binary with magnitudes of 5.6 and
• The Psi1 Piscium pair is magnitude 5.3 and 5.5. Again,
with binoculars you should be able to spot these.
• 65 Piscium is a wonderful binary of equally bright stars.
Both are magnitude 6.3.
M74 is a spiral galaxy seen face on. It's about twenty-two million
light-years away, and one of the faintest Messier objects. To see
this spiral, you will need a large telescope, the larger the the
better. Long-exposure photographs show two or three loosely wound
spirals spinning out from a small bright nucleus. If you have access
to a good telescope, look 1.5 degrees east-northeast of eta Piscium.
THE PLANETS, THE MOON, THE GEMINIDS,
AND THE SUN
• Look for Mercury low in the dawn sky this month. It
will be highest in the morning sky on December 12 and can be seen
to the lower left of Jupiter that morning.
• Venus is low in the west after sunset. The planet will
become even brighter throughout the month, about a -2.8 magnitude
in early December, but finishing the month at a brilliant -0.2
magnitude. It will also set earlier each evening and will disappear
below the horizon by 8:00 p.m. at the end of the month. Venus
is near the waxing crescent Moon on December 4.
• Mars, too, is putting on a great show in the eastern evening
sky. Like Venus, it is hard to miss. It is actually brighter then
Venus early in December (magnitude -1.7), but will not brighten
as fast as Venus. Mars ends the month at a -0.7 magnitude. The
waxing gibbous moon passes Mars on December 11.
• Jupiter is an early riser—around 5:20 a.m. early
in the month and 4:00 a.m. late in the month. It will shine at
a bright -1.8 magnitude. Look for the planet in the constellation
Libra. The waning crescent Moon passes Jupiter on December 26.
• Now is a great time to take a look at Saturn in your new
telescope. Rising a bit before 11:00 p.m. later in the month,
the rings of this planet are positioned for great viewing.
• The Moon is new on December 1 and full on December 15.
The waning gibbous Moon passes Saturn on December 18.
• The Moon is new on December 1, and full on December 15.
• Look for a few Geminid meteors on December 13, the peak
of the shower. Unfortunately, the Moon is nearing fullness and
will make meteors difficult to see.
• The Sun moves west across the zodiac from Ophiuchus and
into Sagittarius. The earliest sunset of the year is on December
• Winter officially begins on December 21, at 11:36 a.m.
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