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Golden Pond Planetarium Journal
We will list the celestial events, significant
heavenly constellations that can be seen in the night skies in Western
Kentucky.
Our partners in offering Summer Nights star
viewing events join us in sharing these thoughts and happenings with you
each month.
Come back often to participate in the experiences that
the dark skies of LBL share with all of us.....
The most recent entry is
immediately below this line.
Read down to experience the
year.
July 2007 The Milky Way
The
quiet, peaceful nights of winter have now been replaced by summer nights
full of the sounds of life. Cicadas, crickets, whippoorwills and barred
owls provide a symphony for our ears while the stars of summer provide a
symphony for our eyes. Go outside on a warm July night and look up at
the stars. Everything you see is just a small part of a much larger
collection of stars called the Milky Way Galaxy. Our star, the Sun, is
only one of more than a hundred billion other stars in the Milky Way.
This galaxy of ours is shaped like a flat, circular disk with a bulge at
the center and arms that spiral around it like a pinwheel. On a clear,
dark summer night in the country, you can see a pale glow arching
overhead from South to North. This is just the glow of that disk of a
hundred billion stars seen edge-on. When we look at this band of light
we are looking out along the plane of the galaxy.
Looking
south, just above the horizon is a fairly easy constellation that looks
a little like an old-fashioned teakettle. This is the constellation
Sagittarius (the Archer). When we look this way we are looking toward
the very center of our galaxy.
To the
right of Sagittarius you will find another easy constellation called
Scorpius (the Scorpion). At its heart lies the bright star Antares
(15th brightest star in the night sky). To the upper right of
Antares lie three stars in a row, which represent Scorpius’ head and
pincers. Trailing off to the lower left (often behind the treetops) find
the curling stinger.
Just above Scorpius
are two linked constellations covering a large expanse of sky. There are
no bright stars here, so you may need a good star map to find them.
Serpens (the Serpent) is the only constellation that is divided into two
parts: Serpens Caput (the Serpent’s Head) and Serpens Cauda (the
Serpent’s Tail). Between these two halves of Serpens is the
constellation Ophiuchus (the Serpent Holder) shaped a little like a
house with a pointy roof.
Just
above Serpens Caput and to the left of the bright star Arcturus
(see May 2007 entry) is a small string of stars that look like a
backwards “C”. This is the constellation Corona Borealis (the Northern
Crown) and it contains one fairly bright star as its main jewel called,
appropriately enough, Gemma.
To the
left of Corona Borealis, and nearly overhead, is a slightly lopsided
square of four fairly bright stars forming the body of the constellation
Hercules. This asterism is called the Keystone and is only the
central part of a large spreading constellation of dimmer stars.
Lastly,
just to the left of the Keystone is the bright star Vega (number
five in our list of brightest stars) and its associated small
constellation Lyra (the Lyre). Lyra consists of a parallelogram of four
dimmer stars, just to the lower left of Vega.
There
are many jewels in the summer skies worthy of study with a telescope.
One outstanding example is called the Great Globular Cluster
(also known as M13) In Hercules. Along the western edge of the
Keystone of Hercules lies a small, round “fuzzy” spot easily seen in
binoculars. Through a telescope, on a clear, dark, moonless night, this
fuzzy spot resolves into a beautiful sphere of hundreds of thousands of
stars and looks like diamond dust sprinkled on black velvet. Many of
these clusters (called globular clusters by astronomers) surround our
galaxy. M13 lies about 23,400 light years away and is about 140 light
years across.
Come
see M13, as well as many other night sky treats, at one of our LBL
Summer Nights programs every Saturday evening from Memorial Day
until Labor Day. Take in a show at the Golden Pond Planetarium
and afterwards, let members of
The West Kentucky Amateur
Astronomers be your guides to the dark Kentucky skies.
“It was as if a
globe had been filled with moonlight and hung before them in a net woven
of the glint of frosty stars...”
--- J.R.R. Tolkien, The
Hobbit (prequel to The Lord of the Rings)
May there always
be starlight on your path,
Bob Vickers
West Kentucky Amateur Astronomers
Further Reading: Seeing in the Dark, by Timothy Ferris
Next Month:
Shooting Stars and Smoke Rings in Space
June 2007 Daytime Astronomy?
When I
was very young, I used to love the Hidden Pictures section of
Highlights for Children magazine. In a drawing of a tree, for
example, there might be hidden images of birds, squirrels, snakes, etc.
– hidden, but in plain view. Observations of nature are filled with
examples of “hidden” things. You see the exquisite colors of a redbud in
bloom, but do you see the motionless rabbit at its base munching on
clover? You see the glorious sunset with golden rays of light streaking
through the clouds, but do you see the hawk perched on top of the
telephone pole right in front of you? Or, maybe, you see the huge gray
and white rain cloud shaped like a turtle, but do you see the sliver of
a crescent moon halfway up the sky? In fact, the 19th century
philosopher and historian, Thomas Carlyle once said, “The tragedy in
life is not what men suffer, but what they miss!”
In many
of the public “sidewalk astronomy” events I have helped with, over the
years, we have set up telescopes with special filters, during the day to
look at the sun. (Warning: Whether you are using a telescope,
binoculars or your naked eye, direct solar observing should only
be done with special good-quality filters designed for that purpose.
Otherwise, you can seriously and permanently injure your eyes.)
Sometimes, the moon would also be visible so we would train our
telescopes on it as well. At more than one of these events a person
expressed astonishment to me that the moon is actually visible during
the daytime. They seemed to think that it only came out at night. I
can’t help but wonder if these people have gone through life with their
eyes closed!
Of
course, the stars and planets are still there during the day. They are
just overpowered by the glare of the sun. Believe it or not, in addition
to the sun and moon, some planets and even the brighter stars are
visible during the daylight hours! You just have to know exactly where
to look. Galileo proved this in 1635, not long after the invention of
the telescope, by observing the bright star Arcturus (see last
month’s journal entry) during the daytime.
At the
West Kentucky Amateur Astronomers meetings (www.wkaa.net),
held at the Golden Pond Planetarium in the Land Between the Lakes, we
usually set up our telescopes before sunset and it has become a bit of a
game amongst us to see who can be the first to spot one of the brighter
planets (such as Venus, Jupiter or Saturn) or stars. Usually, someone
will succeed, perhaps with the aid of binoculars, before the sun has
fully set.
In
April, WKAA and the Golden Pond Planetarium held our annual Astronomy
Day event for the public. Again, we had telescopes set up for solar (and
lunar) viewing, and one of the amateur astronomers in our group (knowing
where to look) managed to find Venus through the observatory telescope.
By sighting along the outside edge of the telescope tube several of us
could actually see Venus with our naked eyes in the middle of the day!
In
2003, the planet Mars made an historic close approach to Earth and was
thus very bright in the sky. One morning, I got up before dawn to
observe it through my telescope at home. As dawn approached, I kept
watching. Mars stayed visible through sunrise and was an eerily
beautiful sight with its orange surface against a background of blue
sky.
Other
objects, such as comets and supernovae have also been visible, at
various times in the past, during the daytime. So, keep your eyes open
and pay attention to the sky – night and day!
I hope
you got to see last month’s spectacular pairing of Venus and the
crescent moon. It was really something to see. This month, the crescent
moon joins the planets Saturn and Venus, but not
quite so close. On the evening of the 17th, the moon appears
to the lower right of Venus while Saturn appears to its upper left. On
the evening of the 18th, the moon has moved in between Saturn
and Venus making a nice triplet. Finally, at dusk on June 30th,
Saturn and Venus have a close encounter, with Saturn just a little more
than a moon’s width above Venus. Look to the West after sunset to enjoy
that show, then look behind you to enjoy another show as the full moon
rises in the East.
Jupiter rises in
the East-southeast around sunset this month and remains visible all
night long.
Summer
officially begins on June 21st, the longest day of the year.
Why not make use of this extra daylight and look for Venus before the
sun goes down in the Western sky? Or, at least try to spot that clover
munching rabbit!
“…beauty and grace are performed
whether or not we will or sense them. The least we can do is try to be
there.”
--- Annie Dillard,
Pilgrim at Tinker Creek
May there always be
starlight on your path,
Bob Vickers
West Kentucky Amateur Astronomers
Further Reading:
Seeing the Sky: 100 Projects, Activities & Explorations in Astronomy,
by Fred Schaaf
Next Month: The
Milky Way
April 2007 Entering the Lion’s Den
The warmer days of
April bring a profusion of blooms, birds and butterflies, while the cool,
clear evenings bring a profusion of stars. Just how many stars you see
depends on how dark your skies are. If you live in the country like I do,
you will see more stars than if you live in or near a city. Unfortunately,
our heritage of beautiful dark skies is endangered, even here in the
country. A combination of air pollution and light pollution has reduced
the number of stars visible across much of the United States. In pristine
dark sky locations a person can see an average of about 2500 stars in the
sky above them. In the city, they may only see one or two dozen. Nowadays,
especially in the eastern half of the United States, few really dark sky
sites are left, and most people never get to experience a sky truly full
of stars.
How dark are your
skies? Go outside on a clear night and face north. The Big Dipper,
an asterism easily recognized by most people, will be high in the sky and
“upside down.” The two stars that make up the front of the bowl are called
the Pointers because they point (nearly straight down
on April evenings) toward the moderately bright star Polaris,
the pole star. Polaris is also the tip of the handle of the Little
Dipper asterism. Made up of considerably dimmer stars than the Big
Dipper, the Little Dipper curves away to the upper right and ends with two
slightly brighter stars at the front of its bowl called the
Guardians of the Pole. If you can readily see all seven stars of
the Little Dipper, you have good dark skies. If you can see just Polaris
and the Guardians, your skies are only fair to poor.
You can help fight
light pollution by using only “full cutoff” outdoor light fixtures which
block light from going up into the sky and keeps it shining downward where
it belongs. Because half the light isn’t wasted lighting up the underside
of passing airplanes, it allows the use of lower wattage bulbs that
require less electricity! Since there is less direct glare, it also
provides better security. (Visit the International Dark Sky Association’s
web site at
www.darksky.org for more information.)
If you have a
telescope, or even a pair of binoculars, take a closer look at Polaris.
You should notice that it is part of a small, uneven ring of very dim
stars to its lower left, about the size of the full moon. This is a
charming little asterism call the Engagement Ring, with Polaris as
the diamond setting. The sky is full of interesting patterns of stars like
this and I will share several of them in the months ahead.
Last month, I
mentioned the bright star Regulus in the constellation of Leo (the
Lion). Situated at the base of “the backwards question mark” or “sickle”
asterism, Regulus is also called Cor Leonis which means the
Heart of the Lion. If you have fairly dark skies and an open horizon
to the south, you may be able to find two more constellations. Crater
(the Cup,) just south of Leo, and Corvus (the Crow,) just east of
Crater. Neither of these constellations contains any bright stars so use
the chart to find them.
Brilliant Venus
climbs ever higher in the western sky this month. Gradually increasing in
brightness, it is visible right after sunset. Saturn is a little
dimmer this month but is still easily visible high in the south on April
evenings. On April mornings, Jupiter appears high and bright in the
south before dawn.
April’s full moon is
often called the Egg Moon, and occurs this year on April 2nd,
rising as the Sun is setting. On the evening of April 19th its
thin crescent makes a beautiful pairing with the planet Venus and appears
just to its lower right. A gibbous Moon lies to the upper right of Saturn
on the evening of April 24th.
The Land Between the
Lakes National Recreation Area is fortunate to have some of the darkest
skies in western Kentucky/Tennessee. Come visit the Golden Pond
Planetarium and attend a meeting of the West Kentucky Amateur Astronomers
at the Observatory (www.wkaa.net
). Meetings are held monthly at 7 p.m. on the Saturday nearest the new
moon. If skies are clear the members usually set up their telescopes and
observe. Visitors are welcome. Plan also to attend our Astronomy Day event
from 10 a.m. til 4 p.m. at the planetarium on April 21st and
learn more about how to get started in astronomy!
“The moon and the stars no longer come to
the farm. The farmer has exchanged his birthright in them for the wattage
of his all-night sun. His children will never know the blessed dark of
night.”
--- Leslie C. Peltier,
Starlight Nights
May there always be
starlight on your path,
Bob Vickers
West Kentucky Amateur Astronomers
Further Reading:
Starlight Nights: The Adventures of a Stargazer, by Leslie C. Peltier
Next Month: The Bear
Necessities
March 2007 A Beehive of Activity
The days are a little
longer now, the nights not quite so cold. Crocuses emerge from their
underground winter slumber to be warmed by the daytime sun, while the
stars of spring glide silently into our evenings. Unlike the icy bright
stars of winter, the springtime stars are not so bright. Only a couple can
even begin to compare to last month’s sparklers. One of these, Regulus,
in the constellation Leo (the Lion) can be seen this month in the early
evening hours, but it only ranks twenty-first in the list of brightest
stars. To the south and a little west of Regulus is a moderately bright
star called Alphard in the long and meandering constellation of
Hydra (the Water Snake).
But what the
springtime lacks in bright stars, it makes up for with other, subtler,
treasures. Facing south, use the diagram to locate Pollux and Castor, two
of the stars from last month’s entry, which are nearly overhead now. Scan
to the east and slightly south to find the planet Saturn and beyond
it, Regulus. Now, go back and look at the space between Saturn and Pollux/Castor.
You will find a very lackluster constellation shaped like an upside down
“Y” and made up of rather dim stars. This is the constellation Cancer (the
Crab). If your skies are dark and clear, you may notice a small fuzzy
patch of light near the center of Cancer. Known since antiquity, this
small blur is called Praesepe (the Manger), and the two nearby
stars are called the Donkeys. If you train a pair of binoculars on
Praesepe, you will see (as Galileo did 400 years ago) that it is really a
small “swarm” of stars of a type that astronomers call an open cluster. In
fact, its more popular name is the Beehive Cluster. Through a small
telescope, this cluster is most striking, with 15-20 brighter members and
a host of dimmer ones. About 200 stars belong to the Beehive. Galileo
counted 40, how many can you count?
Since the distances
between the stars are so vast, astronomers must use a very long unit of
measurement. Mere miles are way too short. Instead, they use something
called the light-year which is the distance that light can travel
in one year (about 6,000,000,000,000 miles). Light is extremely fast, but
it is not instantaneous. It takes time to get from one point to another.
Light from the Moon takes about 1-¼ seconds to reach our eyes - light from
the sun, a little over eight minutes. The light from Sirius (one of the
closest stars) takes about 8.8 years to reach us and so is said to be at a
distance of 8.8 light-years. The Beehive Cluster lies about 577
light-years away.
As mentioned earlier,
Saturn is now high in the east-southeast during the early evening and
remains visible most of the night, setting in the west before dawn.
Venus continues to increase in both brightness and height above the
horizon this month, prompting a corresponding increase in UFO reports! It
blazes mysteriously in the west-southwest just after sunset. Jupiter
comes up around midnight now, and though it is not as bright as Venus, it
is still a grand sight high in the south before dawn.
In the early evening
of March 1st, the nearly full Moon makes a beautiful
pair with Saturn, passing only ½ degree (about one Moon width) north of
the ringed planet. Like ships in the night, these two pass even closer in
the late evening of March 28th. The Moon also passes through
the shadow of the Earth, resulting in a total lunar eclipse on March 3rd.
Unfortunately, from our location in Western Kentucky/Tennessee, most of
the eclipse will be over before the Moon rises. Totality will be ending
just as the Moon is coming up in the east around 6p.m. and the Earth’s
shadow will slowly slide away over the next hour and a quarter. Still, if
you have an open horizon to the east, it is a show of nature well worth
watching (even if we can only catch the final act!)
Spring begins on
March 20th with the promise of many warmer starry nights to
come. You don’t need a computer-guided telescope, or even binoculars to
enjoy them. Dark skies and soft warm eyes will do.
“Just wander off by yourself
And look up from time to time,
In perfect silence,
At the stars…”
-- Walt Whitman
May there always be
starlight on your path,
Bob Vickers
West Kentucky Amateur Astronomers
Further Reading:
365 Starry Nights: An Introduction to Astronomy for Every Night of the
Year, by Chet Raymo
Next Month: Entering
the Lion’s Den
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