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How To Find Scorpius, Sagittarius,
Jupiter, the Milky Way, Antares,
Star Clusters, the Perseid Meteor Showers
& Much, Much More
by David van Popering
August 2008
Each season has signs that foretell of
its arrival, much like a robin is a reminder of Spring.
As an amateur astronomer and staff member of the Custer
Institute, it should come as no surprise that the signs
I look for are in the stars.
On an April morning around 4:00am, I
went outside and looked up, as an astronomer often does,
and there it was low in the south: Scorpius. The way the
Earth turns and the stars seem to slide along the sky,
I knew Scorpius would arrive in its more familiar time
slot around 9:00pm later this summer.
Center
Stage: Scorpius
Scorpius is a constellation that dominates
the summer sky, and, unlike most constellations, this
one looks almost exactly like what it's supposed to be,
a scorpion. (Don't make a common mistake and say Scorpio.
That's the name of the astrology character!)
Since most people can find the Big Dipper,
we will use that to find Scorpius. Follow the arc of the
Dipper's handle to a bright star called Arcturus, a little
more south of west. As far as you turned from the Big
Dipper's handle to find Arcturus, turn that much again
and you should see Scorpius low in the Southern sky. Here
is a star map top help you...
Scorpius
low in Southern sky
Jupiter:
This Summer's Most Prominent Planet
A bit behind Scorpius (more to the east,
that is) we find Sagittarius, the archer. Just as the
Big Dipper is a smaller yet more familiar part of Ursa
Major, the "Teapot" is the smaller, familiar
part of Sagittarius. If you’re up late hunting scorpions,
then look just above the Teapot's handle for an even brighter
object. That’s Jupiter, the sky’s most prominent
planet this summer. (Saturn and Mars will be pretty much
setting with the sun this month. You can see Saturn again
next January rising around 9:00pm).
Scorpius
and Sagittarius
Galactic
Proportions & Speeds
These two constellations lie along what
appears to be a hazy area, which is our own galaxy, the
Milky Way. Just pointing your telescope or binoculars
in the direction of these two on a clear, dark night,
will reveal a background of countless stars that make
up our galaxy.
Think about this: we, along with the
rest of the solar system, are racing around the galactic
center at about a quarter million miles an hour. We can
only see a few thousand stars at most with our unaided
eyes but they are only a tiny fraction of the 100 billion
stars in our own galaxy.
Luke Skywalker said, "Well, if there's
a bright center of the universe, you're at the planet
it's farthest from." I don't know about the center
of the universe, but if you want to head for the bright
center of our galaxy, you would generally head south,
toward Sagittarius. The best guess is that we are 26,000
to 28,000 light years from the center.
Antares
the Super Giant Red Star
The brightest
star in Scorpio is a bit red. This is Antares, a red super-giant
star. It marks the Scorpion's heart. The name Antares
means "Rival of Mars" (people sometimes confuse
it with the red planet). Antares is about 700 times larger
than our sun and if it were placed where our Sun is, we
would be inside it! In fact, it would also engulf Mars
and a bit beyond. In the following diagram, you can see
the comparative size of our sun, Arcturus, and Antares.
Compare
Sizes: Our Sun, Arcturus, and Antares
Beautiful
Star Clusters and the Lagoon Nebula
Just to the right of Antares (west) we
find a globular star cluster otherwise known as M4. Globular
clusters are a hundred thousand to a million stars held
close together by gravity. They are among the oldest objects
in the galaxy and some can be quite beautiful. They sometimes
take on a 3D effect when seen through the magnificent
10 inch binoculars at Custer because you are using both
eyes. You can look through them and meet the man who built
them, Rico Verticchio, any Saturday night.
Another kind of star cluster, an open
cluster, can be found here too. That's M7, also known
as "The Scorpion's Tail." This one is made up
of only about 80 stars and sits on or near the scorpion's
stinger.
Moving into Sagittarius, we find another
globular cluster, M22. This is one of the brightest and
more remarkable clusters in the sky and well worth a look.
It's about 10,400 light years away, which means the light
we see is 10,400 years old. The light you see now left
there at the end of the last ice age here on earth.
The Lagoon Nebula is here too (known
to astronomers as M8) and is about 5,200 light years away.
Stars are forming in this cloud of dust and gas and a
considerable cluster of young stars has already formed.
There is still so much more to see in
and around these two magnificent constellations and I
sincerely hope you come to Custer and have a look some
dark clear night.
The
Return of Perseus and His Meteor Shower
August 12 marks the peak of one of the
more famous meteor showers, the Perseids. This is when
the Earth, on its trip around the Sun, passes through
the left over debris from comet Swift-Tuttle. Be sure
to come to Custer on Saturday the 9th to see the beginning
of this exciting meteor shower. Some people bring blankets,
beach chairs, and snacks and sort of camp out for a few
hours with family and friends. Some people see as many
as 90 meteors an hour. Fortunately the moon will be half
(or first quarter) and already well in the setting west
by 9:00pm, so it will be dark during that prime meteor-spotting
time of after midnight.
A lot of people recognize the "W"
shaped constellation. Perseus the hero is near to the
queen Cassiopeia, sitting on her W throne. Set up your
beach throne to face them and enjoy the meteoric fireworks
show. Here is a map to help you get your chair facing
the right direction:
Perseids
map
There is so much more to see in the sky
this summer and we hope you stop by any Saturday evening
from dusk till midnight and see your universe. Rain or
shine there is still so much more to see and do down at
Custer! Check the Custer website
for details.
Clear Skies,
David van Popering
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