Skywatch January 2006

Skywatch Line January 4, 2006
By Bernard Forman

Today, the Sun sets at 4:35 PM.  The waxing crescent Moon, in the constellation of Aquarius, sets at 10:19 PM.  First quarter moon occurs on Friday.

Venus, at brighter than minus four magnitude, sets at 5:55 PM in the west southwest.  Less than 15 degrees from the Sun, Venus is very low in the sky at sunset.

Mars, in the constellation Aries, continues to dim and grow smaller.  Now dimmer than minus one magnitude and less than twelve arc seconds in apparent size, it is no longer an interesting target in all but the largest amateur telescopes.

Saturn, in the constellation Cancer, continues to brighten.  Now brighter than zero magnitude, Saturn passes the meridian at 1:45 AM Thursday morning.  Saturn is approximately two and a half degrees from M 44, the Beehive Cluster.

At 10:00 PM tonight, we have, yet again, another example of how the sky continually changes, by presenting constellations associated with three seasons.  Setting in the west is Pegasus, with the Great Square still, barely, visible, followed by Andromeda.  Of course, the winter constellations dominate the sky, particularly that most prominent of constellations, Orion.

In the east, the sickle of Leo, the Lion, is clearing the horizon.  By midnight, this constellation, which we associate with spring, will be in full view.

Now is an excellent time to observe the winter Milky Way.  Though not as prominent as the Milky Way of summer, since we are facing away from the center of our galaxy, it is still a beautiful sight, particularly worthy of scanning with binoculars.

 Since open clusters are found near the plane of the Milky Way, the winter sky contains many prominent open clusters.  In addition to the Hyades and Pleiades, in Taurus, Cassiopeia and Auriga are filled with numerous open clusters suitable for viewing with binoculars or a small telescope.

Skywatch line for Thursday, January 5, 2006
by Ray Bogucki

   This week the Earth is at perihelion, its closest approach to the Sun in its annual orbit.  Many people are surprised to learn that we are 3 million miles closer to the Sun these short, dark, cold winter days than we will be next 4th of July with its long days and hot weather.  This circumstance helps to moderate the extremes of our seasonal temperature variations to a small degree.  Our less fortunate neighbors in the southern hemisphere are now experiencing their hot summer season while the Earth is closest to the Sun, and will spend their winter farther from the Sun.
  This annual change in distance from the Sun was explained by the young German mathematician and physicist, Johannes Kepler, who proposed in 1609 that orbiting bodies travel around their parent bodies in orbits that are not circular, as Copernicus believed, but elliptical.  The Sun lies not at the geometric center of the oval-shaped orbit, but at a focus closer to one of the pointed ends of the ellipse.
  Kepler also proposed that an orbiting body travels faster in its orbit when it is closer to the parent object.  In accordance with Kepler's laws, the Earth travels a slightly shorter distance at somewhat higher speed in the winter between the autumn equinox and the spring equinox than it does between the spring and fall equinoxes.  The result is immediately apparent if one counts the number of calendar days in the two periods.  The longer distance and slower orbital speeds during the summer season require six more days than the winter season has.
  By far, the largest factor in our seasonal temperature variation is the 23-degree tilt of the Earth's rotational axis from a line perpendicular to our orbital plane.  At the winter solstice, the north polar axis is tilted 23 degrees away from the Sun.  At noon in Albany, the Sun rises only about 24 degrees above the southern horizon and the Sun's low, slanting rays deliver a greatly diminished amount of energy to each square meter of the Earth's surface, so the temperature is low.  At the summer solstice, the north polar axis is tilted toward the Sun, which climbs to 71 degrees at noon, providing its energy at a much steeper angle.  Each square meter absorbs more energy, so the temperature of the surface becomes warmer.

{Submitted by Ray Bogucki  (bo-good'-ski)}

Skywatch Line for Friday, January 6, through Sunday, January 8, 2006
by Alan French

Venus, which dominated the evening sky for most of the last half of 2005, is now rapidly moving lower in the sky, and will sink out of view early next week.  Like the Moon, Venus shows phases, and right now, it is a very slender crescent.  This crescent is just large enough that people with above average vision may be able to see it – especially if they use a trick to improve their vision.  (More about this in a minute.)  If you fail to see the crescent with your eye alone, it is quite easily seen in binoculars.  Be sure to look just after sunset, when Venus will be highest and the bright sky will suppress the brilliance of the planet.

Before going out to look, take a piece of aluminum foil, and use a fat needle or thin nail to make two small holes in the foil.  One should be about 2 millimeter in diameter, and one about 1 millimeter in diameter.  Try to make them as round and even as possible, and space them a few inches apart.

Venus will be low in the southwest just after sunset.  As the Sun sets at 4:37 on Friday night, our sister planet will be only 10 degrees above the horizon, above and somewhat left of where the Sun disappeared.  Look to see if you can spot Venus's crescent right after the Sun just vanishes below the horizon.  If you can't see the crescent, look at the planet through the
larger hole in the aluminum foil.  This allows you to use only the center of your pupil, which should make the view sharper.  Can you see the crescent now?  If not, try the smaller hole and see if that helps.  If you still have no luck, binoculars, or any telescope, will easily reveal the thin crescent. If you use a telescope, the lowest power will give the best view.

Youngsters often have more success than adults spotting the crescent of Venus, so please invite your children to try.  If they do see it, they should report that the fattest part or middle of the crescent is toward the sunset glow, and the tips of the crescent point away from the Sun.

On Saturday, the Sun will set at 4:38, when Venus will be only 9 degrees above the horizon.  By Sunday, Venus will be 8 degrees above the horizon at the 4:40 sunset.  I am ready to try for the crescent Venus, so I hope we finally get some clear skies!

This is the Skywatch Line for Monday, January 9.
by Joe Slomka

 The Sun sets tonight at 4:40, with night falling at 6:21 PM. Dawn breaks at 5:44 AM, with sunrise taking place at 7:25.

As the Sun sets, the eleven-day old Moon dominates the southeastern sky. As the sky darkens, train your binoculars or telescope on the Moon. To its immediate left, the Pleiades, a beautiful star group shines. Over the night, the Moon eclipses some of the group as it traverses eastward.

Mars is found to the Moon's lower right. The Red planet is still quite bright, but fading fast.

Yesterday, January 8, was the Christian feast of the Epiphany, otherwise known as "Three Kings Day." But, who were these "kings?" Most likely they were Magi from the eastern empire of Babylon. The Babylonians were famous for their astronomical skill. By 2000 BC, they identified all five visible planets, the major constellations, the zodiac and the Saros cycle of eclipses. These priest-astrologers were very powerful and respected throughout the known world.

These dedicated sky watchers would certainly have noticed any new object or event in the night sky. While some think that a comet or supernova may have been the "Christmas Star." The prevailing opinion is that it may have been an astrological event: the most likely being at triple conjunction between Saturn and Jupiter during the year 7 BC. During the course of the year, Jupiter appears to: chase Saturn, catch up with it, pass it, turn around and catch up with and pass Saturn again, and finally catch up with Saturn one more time before sailing eastward past it. This startling series of events took place in the Pisces, a significant constellation. While we now know the planets to be worlds like our own Earth, to the ancients stars and planets were messengers from the gods. When two planets, associated with the most powerful gods, keep meeting, the Magi knew something significant was about to happen. These scholars were also familiar with their neighbors. A search of Jewish documents provided the inspiration to set off for that distant land and a possible meeting with a new god-king.


Clear Skies

Joe Slomka

Dudley Observatory Skywatch Line for Tuesday, January 10th, 2006
written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

   Sunrise today was at 7:25 AM, and it set tonight at 4:40 PM. It will rise tomorrow at 7:25 AM, and will set tomorrow at 4:41 PM. 

   The Moon today is in a Waxing Gibbous phase, with the Full Moon on Saturday, the 14^th. It rose this afternoon at 1:13 and will set at 5:30 tomorrow morning.   

    Mars and Saturn dominate the evening sky this month. 

    The planet Mars, looking like an orange-yellowish star, is visible high up in the south, as soon as darkness falls. It is near the star cluster known as the Seven Sisters.

    At the same time, the planet Saturn is up in the east.  This is still one of the best objects to see in a small telescope, as just 30 power will reveal its ring system. The Full Moon will be near the ringed planet on the night of the 14^th.

    The Winter constellations are high up in the south by 9:30 PM.  Look for Orion the Hunter by spotting the three stars in a row that mark his belt.  A line drawn down from the belt points to the brightest star in the entire night time sky, the “dog star” Sirius.

    Public Programs at the Suits-Bueche Planetarium at the Schenectady

Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M.  The 1:00 program

is “The Friendly Stars”, a program for young people. At 2 P. M. is “Cowboy Astronomer”, and at 3 P. M. is a live narration of the Winter Sky.  “Cowboy Astronomer” also plays Tuesday through Fridays at 2 PM.

Skywatch Line for Jan 11, 2006

By Bernard Forman

Today, the Sun sets at 4:42 PM.  The waxing gibbous Moon, in the constellation Taurus, the Bull, has already risen at 1:57 PM, and sets tomorrow morning at 6:28 AM.  Full Moon occurs on Saturday.

Venus, although bright at minus four magnitude, sets at 5:15 PM making it extremely difficult, if not impossible, to see in the bright twilight.  Venus reaches inferior conjunction, that is, it lies between the Sun and the Earth, later this week

Proceeding along the ecliptic, Neptune, at eighth magnitude, is in Capricornus, followed by Uranus, in Aquarius, slightly brighter than sixth magnitude.  Mars, at slightly brighter than zero magnitude, is in the constellation Aries, the Ram, and has shrunk to less than eleven arc seconds in apparent size.

With Mars no longer a particularly interesting telescopic sight, we can turn our attention to Saturn, at slightly brighter than zero magnitude, in the constellation Cancer, the Crab.  Saturn passes the meridian, or transits, at 1:15 AM Thursday morning.  Approximately two degrees to the east, or left, of M 44, the Beehive Cluster, Saturn is probably one of the most beautiful telescopic objects in the entire sky.  Moderate size telescopes show the ball of the planet being somewhat wider than tall, an effect of its rapid spinning on its axis and the planet’s makeup as a gas giant.  Of course, Saturn is most known for its glorious rings, the southern side of which is currently on view.   Virtually any size telescope magnifying thirty times will show the rings.  Additionally, modest telescopes will show several moons swarming around Saturn like bees around a hive.  Appropriate, then, that Saturn is so close to the Beehive Cluster.

Jupiter, in the constellation Libra, doesn’t rise until 2:14 AM on Thursday morning.  Almost minus two magnitude, Jupiter, like Saturn, is wider than it is tall, though the effect is not as pronounced.  Jupiter is best observed in early morning twilight, when it has sufficiently risen above the horizon.

Skywatch line for Thursday, Jan. 12, 2006:
by Ray Bogucki

  As the Earth proceeds in its yearly revolution around the Sun, the apparent path of the Sun against the background stars is called the ecliptic. Because the Earth's orbital plane is tilted about 23 degrees to its equatorial plane, the two planes will cross at two points, known as nodes, that lie 180 degrees apart along the equatorial plane.
   The situation with the Moon is similar.  The Moon's orbital path around the Earth constitutes a plane which is tilted about 5 degrees to the plane of the ecliptic.  Thus, the Moon's path will cross the ecliptic at two nodes, once in each monthly revolution, and never lie more than 5 degrees from the ecliptic.  Also, all of the planets travel around the Sun in orbits whose planes are very close to the ecliptic.  The consequence is that the paths of all of the visible solar system bodies lie close to the ecliptic (except for comets and meteors).
  In its rapid monthly orbit of the Earth, the Moon will pass close to each of the planets, occasionally occulting one or another of them.  In addition, several bright stars, including Aldebaran in Taurus, Spica in Virgo, Regulus in Leo, and Antares in Scorpius lie close to the ecliptic and are occasionally occulted by the Moon.
  If the lunar nodes were fixed in space, the Moon would always follow the same path, occulting the same stars along its path in each monthly orbit.  However, various perturbations, especially the gravitational pull of the Sun, cause the nodes to slide westward along the ecliptic in a 19-year cycle.  Thus the Moon's path through the sky will be slightly different each time it orbits the Earth and it will encounter different stars.  For example, 9 years ago the Moon was passing through the constellation Taurus the Bull, a few degrees south of the ecliptic where it encountered and frequently occulted Aldebaran, the bright red eye of the Bull.  Now, a half cycle later, the Moon passes through Taurus a few degrees north of the ecliptic, where it encounters not Aldebaran, but the best-known bright star cluster in the sky, the Pleiades.  In binoculars, or a small telescope, the sight of the Moon ploughing through a cluster of stars is fascinating.  Each star reaches the edge of the Moon where it seems to burn for a moment then suddenly disappears only to reappear an hour or so later at the back edge of the Moon.  Fortunately the Moon is now entering a period of several years when it will frequently occult part of the Pleiades cluster and afford us many evenings of spectacular skywatching.
(Ray Bogucki)

Skywatch Line for Friday, January 13, through Sunday, January 15, 2006
by Alan French
The Moon is Full on Saturday morning at 4:48, so bright moonlight will
dominate the skies over the weekend.  The Full Moon of January is called to
Old Moon or the Moon after Yule.  The Sun now sets around 4:45.  On Friday,
the Moon will be rising in the east-northeast an hour before sunset.  By
Saturday night, the Moon will rise just after the Sun sets.  The Full Moon
is often a very pretty sight as it comes up over the horizon.  Notice that
it looks larger than usual when it is near the horizon.  This is an optical
illusion.
We have two good chances to spot the International Space Station, commonly
known as the ISS, over the weekend.  It will be visible in the evening sky
on both Saturday and Sunday nights.  We see the ISS because it is still up
in the sunlight, shining brightly, while we are down in the darkness of the
Earth's shadow.  The ISS moves around the Earth in a little over 90 minutes,
and takes only about 5 minutes to travel across the sky.  It appears as
bright as the brighter stars, and its brightness and rapid motion across the
sky makes the ISS easy to spot.
On Saturday night, the ISS will appear rising up from the northwestern
horizon just after 5:40.  It will be highest and 46 degrees above the north
northeastern horizon at 5:43:05, and will fade from sight as it moves into
the Earth's shadow at 5:45:13.  As it moves into the Earth's shadow, it will
be just 15 degrees above the eastern horizon, so you will need a good clear
view to the east to see the disappearance of the ISS.
On Sunday night, the ISS will travel a little higher in the sky and appear a
little brighter.  It will come up from the west-northwestern horizon at
6:04:55.  Its highest point will be 55 degrees above the southwestern
horizon at 6:07:45.  The ISS will move into the Earth's shadow at 6:09:58
when only 15 degrees above the southeastern horizon.
The Albany Area Amateur Astronomers will meet at 7:30 PM this coming Tuesday
night at the Schenectady Museum.  The program will survey celestial events
of 2006.  Guests are always welcome.

This is the Dudley Observatory Skywatch Line for Tuesday, January 17th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

   Sunrise today was at 7:22 AM, and it set tonight at 4:48 PM. It will rise tomorrow at 7:22 AM, and will set tomorrow at 4:49 PM. 

   The Moon today is in a Waning Gibbous phase, with the Last Quarter Moon on Sunday, the 22nd. It rises today at 8:06 PM and will set at 9:38 tomorrow morning.   

    Mars and Saturn dominate the evening sky this month. 

    The planet Mars, looking like an orange-yellowish star, is visible high up in the south, as soon as darkness falls. It is near the star cluster known as the Seven Sisters.

    At the same time, the planet Saturn is up in the east.  This is still one of the best objects to see in a small telescope, as just 30 power will reveal its ring system. The Full Moon will be near the ringed planet on the night of the 14^th. 

    For those who like to stay up very late, or get up very early, the Planet Jupiter is visible about an hour or so in the southeast before Sunrise.

    The Winter constellations are high up in the south by 9:30 PM.  Look for Orion the Hunter by spotting the three stars in a row that mark his belt.  A line drawn down from the belt points to the brightest star in the entire night time sky, the “dog star” Sirius.

    Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M.  The 1:00 program is “The Friendly Stars”, a program for young people. At 2 P. M. is “Cowboy Astronomer”, and at 3 P. M. is a live narration of the Winter Sky.  “Cowboy Astronomer” also plays Tuesday through Fridays at 2 PM.    

Skywatch line for January 18, 2006
by Bernard Forman
 

Today the Sun sets at 4:50 PM.  The waning gibbous Moon, in the constellation  Leo, the Lion, rises at 9:07 PM and sets tomorrow morning at 9:55 AM.

Venus has just passed inferior conjunction and Mercury will be at superior conjunction later this month so neither is visible.  Mars, although high in the sky, has shrunk to under ten arc seconds in apparent diameter and so is no longer an inviting object for amateur telescopes.  Accordingly, our attention, at least until the Moon does not light up the nighttime sky, is drawn to the planet Saturn.

Go outside tonight around 10:00 PM and face south.  The constellation Orion, the Hunter, dominates the southern sky.  To its lower left is Sirius, the Dog Star, which is the brightest star in the entire sky.  To Orion’s upper left is the constellation Gemini, the Twins, recognizable by its two bright stars Castor, the higher of the two, and Pollux.  Continuing about sixteen degrees to the lower left, we come to Saturn, which is unmistakable as the brightest object in that part of the sky.  In fact, only the Moon and Sirius outshine Saturn.  Even with the gibbous Moon lighting up the sky, binoculars should show M 44, the Beehive Cluster, about one and a half degrees away.

 While best known for its glorious system of rings, moderate size amateur telescopes also display at least five moons, more than that of any other planet.  Titan, at eighth magnitude, is the largest and brightest of Saturn’s moons, and of the five is furthest from the planet.  Also visible in moderate size amateur telescopes are Dione, Tethys and Rhea, all approximately tenth magnitude, and Enceladus, at twelfth magnitude. 

Also visible in amateur telescopes is the moon Iapetus.  Iapetus has an orbit almost three times the size of Titan’s.  Most interestingly, however, Iapetus is considerably brighter on one side of its orbit than the other side.  At western elongation Iapetus’ magnitude is approximately 10.1.  At eastern elongation, its magnitude dims to 11.9.  Apparently, the opposite sides of Iapetus have vastly different reflectivity.

Saturn’s moons do not appear as disks so they can be confused with background stars.  An internet search will reveal a wealth of information about Saturn’s many moons, including the web site of the magazine Sky and Telescope, which provides an application displaying the configuration of the five brightest moons.

Skywatch line for Thursday, Jan. 19, 2006
by Ray Bogucki

  As the sky darkens on any clear night in the coming week, we find the three bright stars that form the "Summer Triangle" preparing to set, low in the west.  With the final departure of this lingering summer asterism, we can turn our full attention to the brilliant stars of our winter skies.
  About 9 p.m., looking southeast, you will be facing what is often called the "Winter Oval" a roughly oval shaped string of brilliant stars that enclose the constellations of Canis Major, Canis Minor, Gemini, Auriga, Taurus and Orion.
  The constellation Orion, the Hunter is the brightest and probably the best-known constellation in the sky, with its rough rectangle of bright stars forming the shoulders and feet of the hunter, with three bright stars in a neat line forming Orion's belt and three dimmer stars in a line forming the sheath of his sword, dangling from his belt.  Just below, and a bit east of Orion, shines the instantly recognizable Sirius, the brightest star anywhere in Earth's sky, sparkling like a diamond and breaking into shards of color.
  Beginning with Sirius, in Canis Major, and moving upward and eastward, we encounter the brilliant, zero magnitude star Procyon in Canis Minor.  Moving northward toward Polaris, we come to  two bright stars close together named Pollux and Castor, which define the positions of the heads of the two Gemini twins of the same names.
  Turning westward we quickly encounter the brilliant zero magnitude star Capella, shining almost directly overhead in the constellation Auriga, the Charioteer.  Dropping down, southward, we encounter Aldebaran, the first magnitude, orange eye of Taurus the Bull.  Continuing south we see the brilliant blue-white giant star Rigel, in Orion's foot, and from there back to Sirius to close the oval.  Enclosed within the oval is the bright, reddish super-giant star Betelgeuse in the shoulder of Orion.
  This winter, the bright oval is enhanced by the presence of the planet Saturn, shining at zero magnitude a bit to the left of Procyon, and the red planet, Mars, receding from us but still shining brightly to the right of Aldebaran.
  It is very satisfying, and humbling, to sit quietly for a while and let the majesty of this collection of celestial beacons, arrayed from the horizon to the zenith, overwhelm your consciousness.

This is the Skywatch Line for Friday, January 20, through Sunday, January
22, 2006
by Alan French

The Moon is at last quarter on Sunday, so the early evening hours will be
dark and moonless over the weekend.  The Sun now sets just before 5:00 PM.

Saturn takes 29 and a half years to complete one trip around the Sun.  In
our Earth's journey around the Sun, we overtake and pass slower moving
Saturn about every 378 days.  This year we will pass Saturn on Friday,
January 27.  This is called "opposition," because Saturn will be directly
opposite the Sun as seen from our Earth.  When Saturn – or any of the outer
planets – is at opposition it rises around sunset, is highest and due south
around midnight, and sets around sunrise.

Look for Saturn above the eastern horizon around 9:00 PM.  The planet will
be due east and 38 degrees above the horizon.  Below and to the left of
Saturn, a little over 20 degrees away, you'll find brilliant Regulus, the
brightest star in Leo, the Lion.  About 16 degrees above Saturn you'll find
the lowest of a pair of bright stars.  This is Pollux, and the other member
of the pair is Castor.  Castor and Pollux are the brightest two stars in the
constellation Gemini, the Twins, and the twins share the same names.

Saturn is now passing right near the Beehive, a large cluster of stars, and
a very pretty sight in binoculars.  If you look at Saturn with binoculars,
you should easily spot the Beehive just above and left of the planet.

With its beautiful rings, Saturn is a marvelous and unique sight through a
telescope.  Almost any telescope providing a magnification of at least 30
should nicely reveal the rings.  A good telescope using about 100 power
should show a dark gap or division in the rings.  This gap, which divides
the outer A-ring from the inner B-ring, is named after it's discover,
Cassini.

Saturn, like the Earth, is tipped on its axis.  Its tilt is almost 27
degrees.  As Saturn travels around the Sun, our view of the ring changes.
Right now, the rings are tipped about 20 degrees from our perspective here
on Earth, and we have a fine view of the rings.

This is the Skywatch Line for Monday, January 23
by Joe Slomka

  The Sun sets tonight at 4:57, and night falls at 6:35 PM. Dawn breaks at 5:40 AM and ends with sunrise at 7:18.

As the sky darkens, Mars is the only visible planet, high in southeastern sky. Its orange color gives it away. As January continues, Mars visibly dims and grows smaller.

Saturn rises shortly before nightfall, but one needs to wait about two hours before it can be clearly observed. To the telescopist, Saturn's rings are a joy, making Saturn a favorite in star parties. A binocular user cannot see the rings, but can wonder at Saturn's close proximity to the Beehive star cluster. Another cluster, M 67, lies just below Saturn and Cancer.

Jupiter rises about 1:36 AM, and, by first light, is well placed for observation of its cloud systems and four Galilean moons.

Shortly before Sunrise, we find Jupiter, a one-third illuminated Moon and the constellation Scorpius all low in the South.

Saturn's proximity to the Beehive Cluster (M 44) provides a theme for the night. Throughout the night, star clusters abound. In early evening, we find the Pleiades above the shoulders of Taurus. The Bull's face is made of another star cluster, the Hyades. The nearby constellation Auriga harbors three clusters. Finally, as previously stated, Cancer contains the Beehive and M 67.

All these are called "Open Clusters." They appear to contain, at most, a few hundred stars, which are widely spaced and irregularly shaped. Open clusters are relatively young, less than a billion years old. They reside in the disk of a galaxy and are relatively small, about 50 light-years across.

There is another class of star clusters. These are called "Globular Clusters." Globular clusters are usually found around galaxy halos and central bulges.
Globulars may contain up to a million stars and are quite large, in a sphere about 100 light-years across. These stars are quite old.

If tonight's weather is clear, binoculars can show many Open Clusters. Just dress warmly and observe the Hyades, Pleiades and the nearby pentagon shaped constellation Auriga.

 

Dudley Observatory Skywatch Line for Tuesday, January 24th, 2006,
written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

   Sunrise today was at 7:21 AM, and it set tonight at 4:59 PM. It will rise tomorrow at 7:21 AM, and will set tomorrow at 5:00 PM.  Since the first day of Winter back in December, we have picked up around 45 minutes of daylight.

   The Moon today is in a Waning Crescent phase, with the New Moon on Sunday, the 29th. This phase of the moon can be seen in the morning and early daytime sky.  It rose today at 2:34 AM and set just before noon.     

    Mars and Saturn dominate the evening sky this month. 

    The planet Mars, looking like an orange-yellowish star, is visible high up in the south, as soon as darkness falls. It is near the star cluster known as the Pleiades, otherwise known as the Seven Sisters.

    At the same time, the planet Saturn is up in the east.  This is still one of the best objects to see in a small telescope, as just 30 power will reveal its ring system.  

    For those who like to stay up very late, or get up very early, the Planet Jupiter is visible about an hour or so in the southeast before Sunrise, and the bright planet Venus is beginning to make an appearance low in the east southeast.

    The Winter constellations are high up in the south by 9:30 PM.  Look for Orion the Hunter by spotting the three stars in a row that mark his belt.  A line drawn down from the belt points to the brightest star in the entire nighttime sky, the “dog star” Sirius.

    Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M.  The 1:00 program is “The Friendly Stars”, a program for young people. At 2 P. M. is “Cowboy Astronomer”, and at 3 P. M. is a live narration of the Winter Sky.  “Cowboy Astronomer” also plays Tuesday through Fridays at 2 PM.

Skywatch Line for Jan 25, 2006
by Bernard Forman

Today, the Sun sets at 4:59 PM.  The waning crescent moon has already set, at 12:26 PM and will not rise until 4:58 AM, tomorrow morning.  New Moon occurs next Monday.

The planet Saturn, in the constellation Cancer, the Crab, reaches opposition on Friday, and so is visible all night.  Saturn is just over one and a half degrees to the lower left of the Beehive Cluster and just over half a degree to the upper right of Delta Cancri, a yellow giant star of approximately fourth magnitude known as Asellus Australis, the “southern donkey”.

The Beehive Cluster, M 44 on Messier’s famous list, is also known as Praesepe, meaning manger.  It contains approximately fifty stars, sixth magnitude and fainter, and is visible to the naked eye as a misty patch.  As the Beehive Cluster covers one and a half degrees of sky, it is best viewed in binoculars or a telescope affording a wide field of view.

At sundown tonight, the bright stars of the Summer Triangle are barely visible in the west and will soon set, only brilliant Deneb being barely visible as late as 8:00 PM.  As the sky gets really dark, the winter Milky Way, passing through Cassiopeia, Perseus and Auriga will become obvious from a dark site.  Unlike the summer Milky Way, which is brighter, the winter Milky Way is difficult to see from a suburban location.  At this time, the Great Square of Pegasus is sinking in the West, and the winter constellations are becoming prominent.

By 9:00 PM Orion, the Hunter, is almost due south.  Now is the time to look for Lepus, the Hare, below Orion’s feet and to the west of Sirius, unmistakable as the brightest star in the entire sky.  Lepus contains a fairly unusual object, a winter globular cluster bright enough, at eighth magnitude, to make Messier’s list as M 79.

And so long as you are in the area, if conditions are good, look about four degree below Sirius.  There you will find M 41, a large and bright open cluster of about eighty stars covering an area of about half a degree.

Skywatch line for Thursday, Jan. 26, 2006
by Ray Bogucki

  In last Thursday's Skywatch line, we described the roughly oval-shaped circle of bright stars known as the "Winter Oval" or "Winter Hexagon".  Most stars that appear bright to our eyes are relatively near neighbors with high intrinsic luminosity and often considerably larger than our Sun.  Detailed examination of most stars reveals that their structures are more complex than is apparent to the unaided eye.
  Beginning with Sirius, the Dog Star, we find that in 1844, astronomer Friedrich Bessel detected subtle variations in the slow proper motion of Sirius which suggested that it had a close companion star.  An intensive search for the companion finally resulted in the sighting, in 1862, of a tiny star buried in the Dog Star's glare, which was nicknamed the "Pup".  This star is the same distance from us as Sirius (about 9 light-years) and has a similar luminosity.  Its faintness thus indicates that it must be very small in size.  In fact, it is about the size of the Earth, though it has the mass of our Sun, and is categorized as a dense white dwarf.  A teaspoonful of the matter on this star would weigh a couple of tons on Earth.
  The next bright star in the Oval, Procyon, is very similar to Sirius, a little smaller and a bit farther away, but amazingly, also accompanied by a white dwarf companion.
   Pollux in Gemini is a normal, single star about 34 light years distant, but with a backyard telescope, its nearby twin, Castor, can be split into two stars of similar brightness, designated as Castor A and Castor B.  A larger telescope can detect a faint red star which is gravitationally connected to the other two.  Spectroscopic studies reveal that each of the three stars is actually a tight, rapidly revolving pair of stars only a few million miles apart, with orbital periods of a few days.  Thus, what appears to our eye as a simple star is actually a collection of six stars whirling madly around each other in a wild celestial dance.
  At the top of the Oval stands zero-magnitude Capella, the northernmost bright star anywhere in the sky.  Spectroscopic studies show that Capella is actually a very close binary with the two components about 70 million miles apart, revolving around each other in a period of 104 days.  A faint red-dwarf pair also revolves around the major pair at a great distance, making Capella a four-component system.  Next Thursday's Skywatch line will cover the remainder of the stars in the Winter Oval.
 

Skywatch Line for Friday, January 27, through Sunday, January 29, 2006
by Alan French
The Moon is new Sunday morning, so the skies will be dark and moonless over
the weekend.
Saturn takes 29 and a half years to complete one trip around the Sun.  In
our Earth's journey around the Sun, we overtake and pass slower moving
Saturn about every 378 days.  Our planet will pass Saturn on Friday, January
27.  This is called "opposition," because Saturn will be directly opposite
the Sun as seen from our Earth.  When Saturn – or any of the outer planets –
is at opposition it rises around sunset, is highest and due south around
midnight, and sets around sunrise.
Look for Saturn above the eastern horizon around 9:00 PM.  The planet will
be a little south of east and 44 degrees above the horizon.  Below and to
the left of Saturn, 22 degrees away, you'll find brilliant Regulus, the
brightest star in Leo, the Lion.  About 17 degrees above Saturn you'll find
the lowest of a pair of bright stars.  This is Pollux, and the other member
of the pair is Castor.  Castor and Pollux are the brightest two stars in the
constellation Gemini, the Twins, and the twins share the same names.
Saturn is now passing right near the Beehive, a large cluster of stars, and
a very pretty sight in binoculars.  If you look at Saturn with binoculars,
you should easily spot the Beehive just above and left of the planet.
With its beautiful rings, Saturn is a marvelous and unique sight through a
telescope.  Almost any telescope providing a magnification of at least 30
should nicely reveal the rings.  A good telescope using about 100 power
should show a dark gap or division in the rings.  This gap, which divides
the outer A-ring from the inner B-ring, is named after it's discover,
Cassini.
Saturn, like the Earth, is tipped on its axis.  Its tilt is almost 27
degrees.  As Saturn travels around the Sun, our view of the ring changes.
Right now, the rings are tipped about 20 degrees from our perspective here
on Earth, and we have a fine view of the rings.

Skywatch Line for Monday, January 30
by Joe Slomka

  The Sun sets tonight at 5:05 PM, with night falling 6:43.  Dawn breaks at 5:41 AM, ending with sunrise at 7:11.

As the Sun sets Mars rides high in the South, while a very thin Moon hovers low above the southwestern horizon. The two-day-old Moon may be difficult for naked eye observers; binoculars may help.

By nightfall, Saturn joins Mars. Mars is still high in the southwest, while Saturn is low in the East. Mars is now left behind a faster Earth, and grows smaller daily. However, it is ideally located for evening observation until Saturn is better placed for watching. In addition, Mars points to a splendid binocular object, the Pleiades, to Mars' left.

Saturn, in about two hours time, is a treat for the observer. In addition to its rings, it is possible to see at least Titan, and possibly smaller moons, depending on the size of your telescope. Binoculars are great for watching Saturn approach and then pass through the Beehive star cluster. Saturn is now moving westward, so it slowly progresses through the cluster. If weather permits, try to chart Saturn's path. Also, do not ignore the other binocular star cluster, M 67 about one and a half binocular fields below Saturn.

Jupiter joins the party about 1 AM, and by dawn is well placed to view it and its moon system. Venus rises later and is low in the East by sunrise. Almost any telescope will show that it is a thin crescent.

As we look at tonight's sky, we may see familiar constellations, The Big Dipper, Orion, Canis Major, etc. Many people know these by Latin or Greek names, but these constellations were visualized differently by other cultures. For example, the ancient Egyptians saw Orion as its chief god, Osiris, while Canis was
Isis, his wife. The Big Dipper is the leg of the evil brother who tried to kill Osiris. The Albany Institute of History currently presents an exhibit of Egyptian artifacts; the Albany Planetarium also presents a complementary show on Egyptian sky mythology


 

Dudley Observatory Skywatch Line for Tuesday, January 31st, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum.

   Sunrise today was at 7:15 AM, and it set tonight at 5:08 PM.

   The Moon today is in a Waxing Crescent phase, with the First Quarter on Sunday, the 5th. It rose today at 8:41 AM and set at around 8:00 PM.    

    Mars and Saturn dominate the evening sky this month. 

    The planet Mars, looking like an orange-yellowish star, is visible high up in the south, as soon as darkness falls. It is near the star cluster known as the Pleiades, otherwise known as the Seven Sisters. On the 5^th, the Moon will be near the Planet Mars.

    At the same time, the planet Saturn is up in the east.  This is still one of the best objects to see in a small telescope, as just 30 power will reveal its ring system. On the 10^th, the Moon will be near the ringed Planet.

    For those who like to stay up very late, or get up very early, the Planet Jupiter is visible about an hour or so in the southeast before Sunrise, and the bright planet Venus is beginning to make an appearance low in the east southeast.

    The Winter constellations are high up in the south by 9:30 PM.  Look for Orion the Hunter by spotting the three stars in a row that mark his belt.  A line drawn down from the belt points to the brightest star in the entire nighttime sky, the “dog star” Sirius.

    Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M.  The 1:00 program is “The Friendly Stars”, a program for young people. At 2 P. M. is “Cowboy Astronomer”, and at 3 P. M. is a live narration of the Winter Sky.  “Cowboy Astronomer” also plays Tuesday through Fridays at 2 PM.

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