These scripts are
written by members of the Albany
Area Amateur Astronomers
and read by the staff
of the Dudley Observatory. All scripts are copyright and may not
be reproduced without permission of the writer and the Dudley
Observatory. Scripts are
published to the web in the week following their recording. Daily
scripts may be heard by calling 518-382-7584 after 5pm.
December 1 -
8 |
December 9 -15 |
December 16 -
22 | December
23 - 29 | December
30 - 31
NOTE: Times given in the scripts are all local
Schenectady, New York time.
Monday, December 2nd. Written by
Joseph Slomka.
The Sun sets at 4:22 PM; night falls at 6:03. Day breaks at
5:27 AM, and ends with sunrise at 7:08.
At sunset, three planets are up, but difficult. Uranus and
Neptune lie South. Neptune is located in Capricornus, while Uranus
is between Capricornus and Aquarius. Both are visible to telescope
uses with detailed star charts.
Saturn is just rising in the East, and gets better as night
progresses. Saturn is easily identified by its brilliant creamy
white color. One can see Saturn in binoculars, but telescopes show
its glorious ring system. Saturn's rings are wide open now, and
continue to widen until April.
Jupiter follows hours later. By midnight it is quite high.
Binocular users see the ball and the four famous Galilean moons.
Jupiter surpassed Saturn as the holder of the most moons, 39. A
committee of astronomers has now assigned names to most of these
newly discovered satellites.
Dawn skies include Venus and Mars. Venus is brightest. Both
planets, separated by less than two degrees, share the same low
power view, and continue their tight formation for the rest of the
month.
High in the southeastern sky lies the constellation Perseus.
Most pictures depict the hero as having one long and one short
leg. One of the stars on the short leg, ALGOL, has been famous for
centuries as a variable star. Every 2.87 days, ALGOL visibly dims.
Since stars were supposed to be perfect heavenly bodies, a star
that periodically brightens and dims must be a "demon star," which
is the translation of its name. Astronomers have figured out that
ALGOL is an eclipsing variable, a star which dims because another
body gets between it and our view. New observations revealed that
the star system is more complicated. The primary star, which we
see, is orbited by a larger but dimmer subgiant, which pours its
matter onto the primary. In addition, a distant, smaller star
about 92 light years from the system's center orbits this pair.
While ordinary eyes or telescopes cannot see this intricate dance,
amateurs still note Algol's cycles and wonder at its beauty.
**********************************************
Tuesday, December 3rd. Written by Jonathan
Cassidy.
Nights this week the nights are dark as the moon is new on
Tuesday. The increasing slim crescent moon can be seen setting
shortly after sun set.
The best show this week is in the morning hours just before
sunrise. Watch in the morning, looking toward the east 1 1/5 to 2
hours before sunrise. You will find one of the brightest objects
in the night sky. Venus now appears in the morning for us. This
week it is in conjuction with the planet Mars.
Get up early and see them together, one bright, white, and the
other dimmer, but noticably redder. They are less than a finger
width apart. Further to the west is the bright star Spica.
Venus is actually closer to Earth than Mars in the solar
system. Mars has recently passed behind the Sun while Venus has
passed Earth between us and the Sun. Their apparent motion takes
Venus closest to Mars on Sunday December 8th. After December 12
the distances between them will increase.
Venus is at its highest in the morning sky now and will set as
a morning object over the next months. Mars will continue to climb
in the sky crossing to the evening sky coming close to Alpha Libra
(the brightest star in the constellation Libra) later in the
year.
**********************************************
Wednesday, December 4th. Written by Mike
Molitor.
The sun sets at 4:22 pm. Nearly 14 hours earlier, at 2:34 am
the Moon was new and a total solar eclipse was visible from the
southeastern Atlantic Ocean, across southern Africa and the Indian
Ocean, to Australia. Surf the Web for news about the eclipse. We
are approaching the longest nights of the year in the Northern
Hemisphere. The end of astronomical twilight this evening is 6:03
pm, and the beginning of astronomical dawn is at 5:29 am tomorrow
morning.
The moon does not brighten the sky tonight, so weather
permitting, faint deep-sky objects can be viewed from twilight
until dawn. Our review of the planets begins with Saturn, which
rises at 5:15 pm, and crosses the meridian after midnight at 12:46
am. The meridian is the imaginary north-south line that goes
through zenith. At magnitude &endash;0.4, Saturn is well placed
for telescopic examination for an hour or two either side of the
meridian crossing.
Jupiter rises at 9:19 pm. At magnitude &endash;2.3 it transits
our meridian at 4:23 am on the 5th. Complete your night of
observing by changing from faint deep sky objects to subtle
planetary details. Look for Jupiter’s Great Red Spot. You can
find it crossing Jupiter’s central meridian at 5:23 am, on
the southern edge of the south equatorial belt.
Mars rises at 3:42 am as a +1.7 magnitude orange "star". Look
for it within two degrees of brilliant Venus, magnitude
&endash;4.7, rising four minutes later. The contrast in brightness
between Mars and Venus is striking. The difference of 6.4
magnitudes means that Venus’s light intensity is 360 times
more than Mars’s. An object’s apparent magnitude is
based on human perception which is logarithmic, while light
intensity is an objective measurement. As you gaze at this pairing
of planets, how do you perceive the difference in brightness
between them? Is Venus 6 times brighter, or 360 times brighter, or
something else?
**********************************************
Thursday, December 5th. Written by Alan
French.
If you go outside tonight, or on the next clear night, around
10 PM you can find all the stars of the "winter circle" above the
eastern horizon. The winter circle is a rough circle formed by
seven of the brightest stars in the winter skies. It is an easy
landmark and a good starting point for locating six different
constellations.
Brightest and lowest of the stars in the winter circle is
Sirius, the brightest star in Canis Major, the Big Dog. You will
find Sirius in the south-southwest not far above the horizon; so
make sure you have an unobstructed view to the south and
southwest. To the left and slightly higher than Sirius is Procyon,
the brightest star in the constellation Canis Minor the Little
Dog. Keeping in mind that a fist held at arms length spans 10
degrees, Sirius and Procyon are just about 26 degrees apart.
Above and to the left of Procyon you will find a pair of bright
stars. They are just a little closer to Procyon than Sirius is.
This pair of stars is Castor and Pollux, the two brightest stars
in Gemini, the Twins, and also the names of the twins. The star
closest to Procyon is Pollux. You should be able to spot the stick
figure bodies of the twins stretching to the right and slightly
upward from the twin stars.
A bit less than 28 degrees above Caster is a very bright star.
This is Capella, the brightest star in Auriga, the Charioteer. If
the star you are looking at is indeed Capella, you will find a
triangle of three fainter stars to its right. The Charioteer often
was also responsible for the livestock, and Auriga is often
pictured holding three young goats. These three stars are often
called "The Kids."
About three fists to the right and somewhat below Capella you
should find a bright and obviously reddish star. This is
Aldebaran, which marks the eye of Taurus, the Bull. A cluster of
stars known as the Hyades make a "vee" that reveals the head of
the Bull.
If you imagine a line connecting Aldebaran and Sirius, you will
notice three stars in a row about at the line's midpoint. These
are the stars making the belt of Orion, the Hunter. The two stars
to the right and slightly lower than the belt stars mark Orion's
knees, and the brightest, Rigel, is the final star in the winter
circle. The two stars above and left of the belt mark Orion's
shoulders. The brightest, Betelgeuse is sometimes added to the
winter circle to make a winter "G".
You may be wondering what the bright yellowish star within our
winter circle is. It is actually a "wandering star," the planet
Saturn.
**********************************************
Friday, December 6th to Sunday, December 8th. Written by
George Mileski
The moon is a waxing crescent moon, it will be at first quarter
on Wednesday the 11th. On Friday, the planet Venus is at its
greatest brilliancy, thats a magnitude -4.7. The only thing
brighter in the sky is the sun and the moon. In the morning sky
you will find Venus and Mars very close together, less than 2
degrees from each other. Further west Jupiter and Saturn can be
seen.
If you look at night in the southwest, you will find the Great
Square of Pegasus, a 2nd magnitude pattern of stars, from which
Andromeda's main line of stars curves away. Lower in the west you
can hardly overlook the magnitude 0 and 1 stars of Vega, Deneb and
Altair of the Summer Triangle having their last seasonal hurrah
before they disappear over the western horizon. Also to be seen is
the M or W, (depending on the time you look at it) shaped pattern
of stars, of Cassiopeia and also Perseus in the North and
Northeast. Perseus's brightest star is Mirfak, the other is Algol
a variable star, its also called the "demon" star.
This a binary of the dark-eclipsing type where the bright
primary is more or less eclipsed by the dark companion. The period
is about 3 days, of which more than 2 days show the "demon" star a
stable magnitude 2.3 near full maximum. When it is eclipsed it is
a very noticable 3.7 magnitude.
East of Cassiopeia we find the celestial winter jewels of
Auriga, Gemini, Taurus and of course Orion the hunter. The sky
from SW to SE is filled with the dim constellations of
Capricornus, Aquarius, Pisces, Cetus and Eridanus. The planet
Jupiter is located in Leo the lion and Saturn is in Taurus the
bull. In a telescope Saturn's rings are tilted beautifully for
observing. They haven't been tilted this much in 15 years, come
next April. Sunday the 8th will be the earliest sunset around
here.
**********************************************
Monday, December 9th. Written by
Joseph Slomka.
The Sun sets tonight at 4:21, with night falling at 6:03 PM.
Dawn breaks at 5:53 AM tomorrow morning and ends with sunrise at
7:15.
As the Sun sets, the only easily visible object is the Moon. It
lies due South, 29 degrees above the horizon. The Moon appears as
a thick crescent. Tonight, the Moon acts as a guide to the
difficult planet Uranus. Uranus lies about five and a half degrees
above the Moon. Most low power binoculars should have both in the
same field. With the Moon out of the field, Uranus should be seen
as a small, green ball. Like Jupiter and Saturn, which appears
later, Uranus is a giant ball of gas. Under ideal dark sky
conditions, Uranus can be seen with the unaided eye.
Saturn rises about the time of nightfall, but is best observed
hours later. Saturn is found at the tip of Taurus' lower horn.
Jupiter rises several hours later and is also best observed about
midnight. By that time, Jupiter is thirty-two degrees high. Those
following Jupiter's path across the sky will now notice that it is
slowly moving westward. This retrograde motion is due to the
orbital game of catch-up that Earth plays with Jupiter.
**********************************************
Tuesday, December 10th. Written by Jonathan
Cassidy.
We have a waxing crescent moon this evening. Even with this
increasing light you can find a star cluster with out using a
telescope!
Find a dark place away from direct lights. If you can not get
out of the city go to the shadow side of a building away from
street lights. Look nearly directly overhead, the zenith.
This cluster of stars can now be found near the zenith of the
sky. Find the familiar "W" of the constellation Cassiopia. Count
from west to east the stars 1, 2, 3, 4. Take a line from 3 to 4
and continue that line beyound 4 toward the next bright star. Half
way there notice that there is a bright patch in the dark night
sky.
This bright patch is the double cluster of Perseus. It can be
seen from most places that are out of direct glare of lights. I
can find it from the Hirsch Observatory on the RPI campus. You
might find it easier if you do not look directly at it but rather
look sideways at it. That will put the image on the part of your
eye that has the most sensative receptor cells, the rods. This
technique, common among those who observe through telescopes is
called "averted vision".
**********************************************
Wednesday, December 11th. Written by Ray
Bogucki.
In the evening sky, the bright constellations of winter are now
rising in the East even as the "summer triangle", consisting of
the bright stars Vega, Deneb and Altair is moving lower in the
West. Astronomers refer to the "winter oval" of seven bright
stars, which begins with the brightest star Sirius, in Canis
Major, then moves eastward through Procyon (PRO-see-yon) in Canis
Minor, and up through Pollux and Castor in Gemini, the Twins. From
Gemini, the oval traces a path northwest to Capella, the
northernmost star in the oval, and thence down through Aldebaran,
the red eye of Taurus, and the blue-white giant Rigel (RYE-jell)
in the foot of Orion, then back to Sirius. Enclosed within the
oval is the red supergiant star Betelgeuse in the shoulder of
Orion, which is joined this winter by the bright planet Saturn,
halfway between Betelgeuse and Capella. When darkness falls,
Capella is already well up in the northeastern sky, and when
Sirius rises a little after 8 p.m., the oval is complete. When
Jupiter, shining at a brilliant magnitude of minus 2.5, rises
about an hour later, the entire southeastern sky is ablaze with
bright objects.
The constellation Gemini is the focus of a major event this
week. The Geminid meteor shower will reach peak activity on Friday
night into Saturday morning, with all the meteors appearing to
emanate from a point within the constellation, Gemini. The waxing
gibbous Moon will interfere with observations on Friday evening
but will set by 2:30 Saturday morning, so the expected peak at 4
a.m. will have dark skies. This is usually a fairly heavy shower,
similar to the Perseids of August, with, perhaps 50 meteors per
hour.
An interesting puzzle is associated with the Geminids. Whereas
most meteor showers are generated when the earth passes through
debris particles left in our orbit by a known comet, no comet is
associated with the Geminids. Instead, a small asteroid named
Phaeton, follows an orbit almost identical with the orbital stream
of the Geminid meteoroids, swinging in to within 13 million miles
of the Sun, and out between the orbits of Earth and Mars, with a
1.5-year orbital period. Since this stony asteroid, about 4 miles
in diameter, shows no comet-like behavior, the source of the
particles remains a mystery.
**********************************************
Thursday, December 12th. Written by Alan
French.
The first half of December gives us the Geminids, the best
meteor shower of the year. The Geminids will peak this year at 4
AM on Saturday morning, December 14th, at a rate of about 90
meteors per hour. After that, the activity drops off sharply so
that few Geminids are visible after December 17. The Geminids is
one of the most reliable and consistant meteor showers, so it is
worth spending some time under the stars over the next two
nights.
Although Friday night and Saturday morning will provide the
highest number of meteors, some Geminid meteors should grace the
skies tonight. For most showers, the hours after midnight provide
the highest number of meteors, but the Geminids is one of the few
showers that often puts on a good show before midnight.
Unfortunately, moonlight will hamper the evening hours this year,
washing out the fainter meteors. Brighter meteors will still be
visible, and you should be able to catch a few after 9:00 PM
tonight. However, the best viewing tonight is under the moonless
skies after 1 AM tomorrow morning far away from outdoor
lighting.
If you want to watch the show near its peak, go our early
Sunday morning after 2 AM, when the Moon will have set. You
should, however, catch some meteors anytime Friday night after
9:00 PM. Evening meteors favor the eastern half of the sky, while
those visible in the middle of the night may be seen almost
anywhere.
Geminids are often bright, but very seldom leave persistent
trains. They display a wider variety of colors than any other
major meteor shower except the Perseids of August. Meteor watching
at this time of the year is a chilling experience. A lawn chair, a
sleeping bag, a heavy hat, and plenty of warm clothes can help
ensure a pleasant stargazing session.
Weather permitting, the Albany Area Amateur Astronomers will be
hosting public stargazing this coming Friday night, December 13 at
the Five Rivers Environmental Education Center in Delmar. The
program will begin at 8:00 PM. At Star Parties a variety of
telescopes are set up to show guests some celestial showpieces,
including the Moon, the Pleiades, the Great Nebula in Orion, and
ringed Saturn. There will also be a constellation tour, featuring
some of the bright constellations of the winter skies and the
mythology associated with them. These events are free and open to
all ages. For directions call Five Rivers at 475-0291. Stargazing
is canceled if the skies are mostly cloudy. Call 475-0291 if you
are unsure or need more information.
**********************************************
Friday, December 13th to Sunday, December 15th. Written
by George Mileski
The moon is in the gibbous phase, which means it is past the
first quarter and will be a full moon on the 19th of December. On
Friday the 13th, the moon is at apogee, which translated means it
will be furtherest away from the earth in its orbit or 251,602
miles from earth. Tonight Friday the 13th, also through early
Saturday morning, we are going to have a meteor shower, called
Geminid. The peak times are after 10pm tonight to dawn on
Saturday. Look in the east near the stars Castor and Pollux, thats
where the meteors will appear to come from or just look up. This
is allegedly a good meteor shower, if you can stand the
cold.
After the big dipper, Orion the hunter is the sky's best known
constellation. Seven striking stars outline the figure of a hunter
taken from the Greek mythology. His sword holds the orion nebula,
M42 which never fails to astonish even the veteran deep-sky
observer. Use binoculars to find it 5 degrees below Orion's three
bright belt stars, from top to bottom Mintaka, Alnilam, and
Alnitak. Through a telescope the nebula gas clouds shimmer in a
greenish light. Orion houses other deep-sky secrets, one is M78, a
small reflection nebula. An object I have never seen through a
telescope is the famous Horsehead nebula. Its very difficult to
see and you need a large aperture telescope to see it, and of
course a very dark location. Orion's mammoth red star Betelgeuse,
gets its brilliance from sheer size. Its predicted that someday
Betelgeuse may go supernova. When it does we'll have a relatively
safe ringside seat from 500 light-years away.
Rigel, a bluish star of Orion shines from 1400 light-years
away. It is more than 50,000 times more luminous than the sun. NE
of Orion, Gemini the twins climb to overhead by midnight or so.
Castor and Pollux are the constellations two principal stars.
Castor is actually a sextuplet system, although through a
telescope we see only two stars.
**********************************************
Monday, December 16th. Written by
Joseph Slomka.
The Sun sets at 4:22, with twilight ending at 6:05 PM. Dawn
breaks at 5:38 AM, and ends with sunrise at 7:20.
As the sky darkens, only the nearly Full Moon is easily
visible. For Capital District viewers, the Moon seems almost
straight up. While the Moon can never be directly overhead, this
is the highest the Moon can ever be - at an altitude of nearly
sixty degrees. Next Saturday is the Winter Solstice, when the Sun
is at the lowest point in our sky. Since Full Moons are opposite
the Sun, this time of year marks the Moon's apex.
Mercury lies low in the West, about seven degrees above the
horizon. Binoculars help in finding this small, but bright,
planet; a telescope shows it about eighty-three percent
illuminated. Mercury is an elusive planet; many famous astronomers
have not seen it. Mercury is nearest to the Sun. As a result, it
never strays too far from the Sun. We know very little about
Mercury. It is slightly larger than our Moon. Mariner probes in
the 1970's revealed a Moon-like surface scorched by the nearby
Sun.
Saturn is up by twilight's end and is easily the brightest
object in the East, besides the Moon. Saturn is slowly moving
westward. It currently lies about a degree and a half from the
famous Crab Nebula. Shortly after New Year, the giant planet will
actually transit this famous supernova remnant.
Jupiter follows several hours later. By midnight, it is quite
high in the East, and replaces Saturn as the brightest planet.
Jupiter is found in the constellation Cancer. Like Saturn, it lies
close to famous deep sky objects, the famous Beehive Cluster and M
67, another star cluster.
Dawn skies find Venus and Mars in a close pairing. Both share
the same two degrees of sky, and are about equally high. Venus is
much brighter than Mars.
**********************************************
Tuesday, December 17th. Written by Jonathan
Cassidy.
Full moon this week leaves us with a bright night. Not as many
stars are visible at night this week than there were two weeks
ago. Thus we need to look for the bright stars that serve as sign
posts for this season.
Once the sky is dark each night notice to the east that there
are more bright stars than to the west. The stars of summer are
setting and the stars of winter are rising. The winter
constellaitons are known for brighter stars, plus we have two
bright planets moving among them.
First of the bright stars to rise is Capella in the
constellation Auriga. Find this star as the brightest star in the
northeast and the first one to be seen each night in that area.
Next is Aldebaran in Taurus the Bull. Then we have the bright
stars of Orion rising; Betalgeuse and Rigel. Notice between these
two the the belt stars of Orion stand nearly straight up on the
horizon. From our lattitude they mark nearly due east. The Next
stars are the twins Castor and Pollux. Castor is first and Pollux
is brighter. Last come Procyone and Sirus.
This completes the winter circle of stars. They will be with us
through the winter and have near them many fine sites for
binocular and telescope observation for the winter season.
**********************************************
Wednesday, December 18th. Written by Ray
Bogucki.
Several notable celestial events occur in the coming week. On
Friday, the Sun reaches the winter solstice, the southernmost
point on its path along the ecliptic, and thus stands lowest for
the year in the south at noon. This configuration produces the
shortest day of the year, with just about 9 hours of sunlight at
the latitude of Albany.
On Christmas Eve, Mercury will be at its brightest and farthest
from the Sun, providing optimum viewing low in the southwest where
it sets about an hour and a half after sunset. On the other side
of the sky, Saturn now stands at opposition, meaning that the
Earth's orbital path has placed us between the Sun and Saturn, so
that Saturn is opposite the Sun in the sky. Saturn rises in the
east as the Sun sets, and sets as the Sun rises, remaining visible
all night. Several factors make this an especially favorable time
to observe Saturn. Even as the Sun is reaching its southernmost
point on the ecliptic, Saturn is reaching the northernmost point
of its travel at 22 degrees north of the celestial equator, so
that it is well-placed very high in the southern sky at midnight.
During the current opposition, Saturn is also approaching
perihelion, its closest approach to the Sun, and therefore also to
the earth, in its 29-year orbit. It now appears as large and
bright as it ever gets. Finally, Saturn's rotational axis is
tilted toward us at near the maximum angle possible, so that its
rings appear very wide, making details in the rings, such as the
Cassini division, especially obvious.
Shining brightly at a magnitude of minus 2.5, Jupiter rises in
the northeast four hours after Saturn at about 8:30. Jupiter's
second moon, Europa, has an orbital period that is just slightly
more than twice that of the innermost moon, Io (EYE-oh). As a
result, for about six weeks out of every 14 months the two moons
fall into nearly synchronous motion as seen from Earth, so that
each time the shadow of Europa transits across the face of
Jupiter, it is joined by the shadow of Io, creating a double
shadow transit, easily visible in a telescope. On Monday night,
you can watch Europa's shadow enter Jupiter's disk at about 9 p.m.
Two hours later, Io's faster-moving shadow will enter and begin to
overtake Europa's shadow. Europa's shadow will then exit Jupiter's
disk just before midnight, followed by Io's shadow an hour
later.
**********************************************
Thursday, December 19th. Written by Alan
French.
Tonight the Moon, just past Full, is quite near the planet
Saturn, and provides a nice landmark to enable you to find the
beautiful ringed planet. If you look toward the East this evening,
the bright star to the upper right of the Moon is actually the
planet Saturn. It will be less than 10 degrees from the Moon all
evening. (If you hold a fist at arms length the distance across
your knuckles is 10 degrees.) While all four gas giant planets -
Jupiter, Saturn, Uranus, and Neptune - have rings, only the rings
around Saturn are bright enough to be seen in virtually any
telescope. Through a small telescope providing a magnification of
30 times or more, Saturn displays a single, bright ring that spans
over twice the diameter of the planet itself. A careful look and
perhaps a bit more magnification may reveal a dark line within the
rings, separating the outer "A" ring from the inner "B" ring. This
is known as Cassini's division, after its discoverer.
Our view of Saturn's rings changes as the planet makes its 30
year journey around the Sun. In 1995 and 1996 the planet's rings
were edge on as seen from Earth, and seemed little more than a
spike of light going through the planet. The rings are now tipped
about 26 degrees toward us, and the next few months will provide
the best view of the rings we have had since 1987 and the best
view we will have for another 15 years. Galileo was the first to
study Saturn through a telescope back in 1610. The changing aspect
of the rings provided a very puzzling view. In some years the
planet was simply a small disk, while in other years it looked
like it had "ears." It wasn't until 1655 that Huygens solved the
Saturn problem by suggesting it was surrounded by a ring.
Larger telescopes may reveal some divisions in the rings and
some subtle detail on the planet. The rings of Saturn are enormous
in extent. From one edge to the other, they measure more than
two-thirds the distance from the Earth to the Moon. The rings are
composed of billions of particles of ice and icy rock, mostly very
small. They orbit Saturn like tiny moons in a ring system which is
less than a mile thick.
Few people fail to be excited by a view of beautiful Saturn,
and this is a wonderful time to see Saturn's rings at their best.
If you don't own a small telescope yourself, perhaps you know a
friend or neighbor who does.
**********************************************
Friday, December 20th to Sunday, December 22nd. Written
by George Mileski
Thursday the 19th was a full moon, so the moon now on Friday
the 20th is a waning gibbous one. On Friday Saturn is located
below and to the right of the moon. On Saturday and Sunday the
moon moves from Gemini into Cancer. One hour before sunrise on
Saturday, Mars and Venus are three degrees apart. On Saturday, 45
minutes after sunset, look for Mercury in the west.
A new comet was discovered on the 14th of December, it is
called comet Kudo-Fujikawa. The comet can be seen before dawn,
about 5AM in the eastern sky in the constellation Hercules, you
need binoculars and a good sky map to find it. On the computer see
the Sky and Telescope website, the site is
"skyandtelescope.com".
Some of the easiest objects in the sky to observe are the
members of our own solar system. The solar system is made up of
the sun at the center, the nine major planets and their moons or
satellites, thousands of minor planets or asteroids, hundreds of
comets, and a great quantity of dust particles. Of the nine
planets, five can be easily observed with the unaided eye because
they are very bright objects. Two of them, that is Uranus and
Neptune, are bright enough to be seen with binoculars. Only one of
them, faint far-away Pluto, is too faint to be seen in binoculars
and can only be seen with a large telescope. The planets are
different from the stars and other objects in the night
sky.
Because they travel around the sun, we cannot mark them on an
ordinary star map and say they will be seen in a certain place at
a certain time of year. We need to describe their positions in a
different way because their motion around the sun means that they
will be in a different place every year.
**********************************************
Monday, December 23rd. Written by
Joseph Slomka.
This is the Skywatch Line for Monday, December 23. The Sun sets
tonight at 4:25 PM, with night falling at 6:08. Dawn breaks at
5:42 AM, and ends with sunrise at 7:24.
As the sky darkens, brilliant Mercury peeks over the
southwestern horizon. Due to its proximity to the Sun, Mercury is
never very high above the horizon. If you can spot the elusive
planet, it appears as a disk about two-thirds illuminated.
Saturn is already high by twilight's end. The ringed planet
lies within Taurus' lower horn, only a degree from the famous
supernova remnant, M1.
Jupiter is well risen by 10:55 PM. It is found about eight
degrees above the Moon. But even the Moon's brilliance cannot wash
out Jupiter's four famous moons. At 10:55 PM, a double shadow
transit takes place. If you have a telescope, you will see not the
moons themselves, but two shadows as they fall on the top surface
of giant planet's clouds.
Venus and Mars dominate the southeast dawn sky. They are
identically nineteen degrees above the horizon and should fit into
the same binocular field. Venus is the brightest and largest.
However, Mars is growing brighter and larger also. A real treat
lies high in the East. The Christmas comet is named Kudo-Fujikawa,
after the two discoverers. As the weeks go on, the comet travels
straight down, and disappears behind the Sun. Catch the comet now,
if you can.
The Dudley Observatory, besides sponsoring this Skywatch Line,
also supports the Star Gazer, on Public Television. The host, Jack
Horkheimer, makes an interesting observation. He notices that the
constellation Cygnus sets in the northwest at about 8PM around
Christmas; Cygnus is also known as the Northern Cross, since, in
its setting position, it indeed resembles the Christian cross. The
Star Gazer also remarks that Cancer rises in the northeast; while
the constellation itself is dim and difficult, a small star
cluster called Praesepe or Manger is easy to spot. Since nearby
stars are nicknamed "the asses," the Star Gazer saw a handy
reference to the Christmas story.
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Tuesday, December 24th. Written by Jonathan
Cassidy.
Near third quarter moon tonight. Good dark skies, in the early
part of the night, for observing. If you can stay up late tonight
you might want to keep an eye to the east as the rising moon is
accompanied by a wonderer.
The word "Planet" is derived from the ancient Greek term
meaning "wonderer". The planets we know do not seem to keep the
same place from year to year or month to month. Thus they seemed
to the Greeks to wonder. Of course they had no idea that these
were astonomical bodies traveling in similar orbits around the
sun.
The planet Jupiter is one of the wonderers that were obvious to
the ancients. Tonight it can be seen to rise with our moon. By
tommorrow the moon will rise sigificantly after Jupiter as they
orbit the sun in different ways. Jupiter progresses a little more
each night from east to west while the moon moves each night more
from west to east. This counter motion must have bothered the
ancients some.
Another wonderer can be seen just 45 minutes after sunset.
Tommorrow Mercury is at it's greatest eastern elongation from the
sun. From a place with an unobstructed western horizon look for
Mercury as the brightest object near the horizon after sunset.
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Wednesday, December 25th. Written by Ray
Bogucki.
This Christmas season finds a bright star shining in the East.
The planet Venus, blazing with a brilliant magnitude of minus 4.5,
outshines every object but the Moon in the early morning sky. It
rises about 4 a.m. and dominates the eastern sky until daylight
overtakes it. In fact, if you calculate precisely where to look,
Venus is visible to the naked eye throughout the daylight
hours.
For the past month, Mars has been the faithful, close companion
of Venus. It currently shines a few degrees to the right of Venus,
about as bright as one of the belt stars in Orion. Still, it is
overwhelmed by its brilliant neighbor, which shines 250 times
brighter. Over the next eight months, the Earth will slowly
overtake Mars which will gradually grow in size and brightness.
When we pass Mars at opposition in late August, it will loom 20%
larger than the current disk of Saturn and shine as bright as the
current appearance of Jupiter.
Last week's Skywatch line observed that Jupiter was going
through a several-week period when the moons Io and Europa, in
near synchronous motion, transit together across the face of
Jupiter and cast their two tiny shadows on the surface of the
giant planet. One of these double shadow transits will begin on
New Year's eve at 48 minutes past midnight.
In addition, Jupiter is now in a a several-month period when
the orbital planes of the four Galilean moons are virtually
edge-on to our line of sight. The effect of this alignment is that
the moons will appear to be traveling back and forth in straight
lines. They will frequently pass in front of one another in a
series of occultations and eclipses. The Belgian astronomer, Jean
Meeus, has calculated the precise timing for hundreds of these
events, which are tabulated in an article on page 100 of the
December 2002 issue of SKY & TELESCOPE. For example, tonight
at 7:05, the moon Ganymede will occult Io and a little later, at
8:45, Ganymede will occult Callisto. In binoculars or a small
telescope, the moons will appear to merge for a few minutes and
then separate again. Watching the rapid change in orientation and
spacing between these occulting moons is quite fascinating.
Galileo would approve!
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Thursday, December 26th. Written by Peter
Jennes.
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Friday, December 27th to Sunday, December 29th. Written
by George Mileski
The moon on Friday December 27th is a waning crescent one. On
Sunday 4 hours after sunset the moon is about 8 degrees above
Jupiter. In the west 45 minutes after sunset, look for the planet
Mercury, it will be seen very low on the horizon, use
binoculars.
It is said that the stars shine more brightly on crisp, clear
winter nights than at any other time. Although the stars may look
brighter, actual measure prove that there is no difference in
clarity between the best skies in winter and those at other times
of the year. The real difference in the winter sky which accounts
for the perception, that the stars are shining more brightly, is
that there are more bright stars. Lots of bright stars should mean
lavishly appointed star groups. Sure enough, the sky's most
impressive constellation Orion, the hunter, lies right in the
middle of the winter sky. Orion is the brightest of all the star
groups, after the big dipper, it ranks as the most distinctive
stellar configuration in the heavens. The unmistakable three-star
belt is unique. Nowhere else in the sky are three stars of this
brightness so close together. Four stars surrounding the belt mark
Orion's shoulders and legs.
Rigel, the brightest star in Orion is one of the most luminous
stars known. Shining about 50,000 times more powerfully than the
sun, this hot blue-white star is 770 light-years distant, more
than a million stars are closer to us than Rigel, but not one of
them can match its mighty energy output. The 2nd brightest of
Orion's suns, Betelgeuse is equally impressive, since it is one of
the largest stars known, with an estimated diameter about 800
times greater than the suns, Betelgeuse would easily enclose the
orbits of Mercury, Venus, Earth and Mars, if it were to replace
our sun. It is a member of class of stars known as red
supergiants. To the unaided eye Betelgeuse is distinctly
ruddy.
So take the time and go out and look at the constellation some
clear winter night.
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Monday, December 30th. Written by
Joseph Slomka.
After nightfall, Saturn lies within a half degree from the
famous Crab Nebula in Taurus.
By midnight, Jupiter is moderately high in the East. As with
last week, Jupiter experiences a double shadow transit. Most
people know that Jupiter's moons circle about the giant planet.
However, if the positions are right, one can see the shadow of one
or more moons march across Jupiter's face. At 12:48 AM, the
shadows of two moons can be seen to cross Jupiter. While
binoculars can spot Jupiter's moons, a telescope is needed to see
the shadows transit Jupiter.
Jupiter is an interesting object for two reasons. First of all,
Jupiter's atmosphere appears as a seething cauldron of various
colors. This is evidence of titanic storms, many of which have
lasted for decades; the Great Red Spot has been observed
continually for about three hundred years. In fact it is possible
to hear the storms. If you have access to a short-wave radio and
directional antenna, you can hear the static these storms
generate. A complex satellite system is Jupiter's other
attraction. Jupiter's moons could not be more different. For
example, Io is a forbidding place where volcanoes spew sulfur and
the surface is stained various colors. While Europa is a frozen
wasteland; ice, many feet thick, covers most of the planet.
As dawn breaks, Venus and Mars are paired in the southeast.
Both planets are equally high. But Venus is much brighter. Mars is
fully illuminated, while Venus is only 44 percent lit. The very
thin crescent of our Moon can be found to Venus' lower left.
Finally, the Christmas comet is still visible high in the East.
Comet Kudo-Fujikawa can be found in dawn skies midway between the
bright constellation Hercules and the horizon.
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Tuesday, December 31st. Written by Jonathan
Cassidy.
The slim waning crescent moon can be seen in the morning just
prior to sun rise. Thus the sky tonight is dark a good time to
look for the planet Saturn.
To find Saturn first find the west and notice the many bright
stars rising in the night. Look for a large "Right Triangle" of
"stars half way up fro the western horizon. One of these is not a
true star but is the planet Saturn.
At this time of the year Saturn, Capella and Aldebaran make a
triangle very near the proportions of the "3,4,5" right triangle
we learned about in high school geometry. This type of right
triangle has angles of 30, 60 & 90 degrees. These angle sets
are particular in that they are pleasing to the eye and thus more
noticable as are equilateral and isosceles triangles.
This grouping of bright objects stands out now but Saturn being
a planet will break this triangle apart by next month and pass the
bright stars as the word planet means "wanderer" in greek. It will
travel through the back ground stars moving each night a little
more east to west. At the time we pass the orbit of Saturn that
planet will appear to move backward or retrograde against true
stars in the night sky. This movement confused early astronomers
and caused them to name to give the name of "planet" to these
wanderers.
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