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Dudley Observatory
Supporting research and education in astronomy, astrophysics, and the history of astronomy |
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Skywatch October 2006 This is the Dudley Observatory Skywatch Line for Tuesday, October 31st, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum. Sunrise today was at 6:27 AM, and it set tonight at 4:50 PM. The Moon is currently in a waxing gibbous phase today, with the Full Moon on Sunday the 5th. It rose at 2:25 this afternoon, and will set after midnight tonight. Comet Swan is still visible as a “naked eye” object, with binoculars giving a better view. It is currently moving through the constellation of Hercules. Try to spot it over the next night or two, although Moonlight may make it difficult to see. Very low to the horizon during this time of year in the evening, is the famous Big Dipper. It is in the north west sky, and appears upright. Using the end stars of the cup, draw a line upwards, and it will point to the North Star, Polaris, on the end of the handle of the Little Dipper. The Little Dipper is “upside down” compared to the Big Dipper. The Square of Pegasus, also known as the Fall Square, is high overhead by 9 PM The only good planet viewing comes after midnight, as the ringed planet Saturn rises after that time. It is also visible in the morning sky in the south. In space news, NASA announced this morning, that there will be a manned Shuttle mission to service the Hubble Space Telescope in 2008, which will keep Hubble running through 2013. The Suits-Bueche Planetarium at the Schenectady Museum has re 0pened and is now running its regular schedule. 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 Sky Above Mister Rogers Neighborhood”, a program for young people. At 2 P. M. is “Hubble Vision”, and at 3 P. M. is a live narration of the Fall Sky. “Hubble Vision” also plays Tuesday through Fridays at 2 PM.
This is the Skywatch Line for Monday, October 30.
This is the Skywatch Line for Friday, October 27, through Sunday, October 29, by Alan French Comet Swan has been a pleasant surprise for amateur astronomers. Several days ago it unexpectedly brightened considerably, and is now a pretty sight in binoculars and faintly visible to the unaided eye under dark skies. It is also fairly easy to locate. The sky will be dark enough for a good view of Comet Swan around 7:30 PM. If you look in the western sky, about 40 degrees above the horizon, you'll spot the keystone of Hercules. Use the right side of the keystone shape to find the comet. Simply point your binoculars at the lower star in the right side of the keystone, and then move them so the star is in the left side of your view. You should see a bright, fuzzy ball in your view, and that is Comet Swan. If the skies are nice and dark, you may be able to see a faint tail. If you have a telescope, the faint tail is easier to see in a telescope. If you are having trouble finding the comet, you can see a finder chart at www.skyhound.com/sh/comets/2006_M4.gif You can also find a chart, and more information on the comet, at skytonight.com. Click on "Observing Highlights," or look for the Comet Swan link under "Observing" on the right side of the page. If you need help finding Hercules, click on the "Interactive Sky Chart" at the bottom of the web page.
Skywatch line for Thursday, October 26, 2006
by Ray Bogucki
At nightfall in late October and early November we can see the familiar W
shape of the constellation Cassiopeia, high in the northern sky above Polaris
the North Star. Actually, as it rotates into position above Polaris, it is
inverted into an M shape. A few degrees to the right of the northernmost star
in the "M" is a soft, naked eye glow known as the double cluster in Perseus.
Binoculars will reveal the double nature of the cluster, while a small
telescope with a wide field will allow to count perhaps a hundred stars in
each cluster, gleaming like blue-white diamonds on a black velvet background,
at the considerable distance of about 8,000 light-years. About 15 degrees to
the south of the southernmost star in the "M" is another naked-eye glow, but
this one, the famous Andromeda galaxy, is about 2.5 million light-years away
and contains hundreds of billions of stars. It is probably the most distant
object visible to the naked eye.
While most galaxies were discovered by Edwin Hubble to be receding from our
galaxy at fairly high speeds, thus leading to the concept of the "expanding
universe", the Andromeda Galaxy is actually approaching us at about 75 miles
per second, or 270 thousand miles per hour. Astronomers estimate that in,
perhaps, 3 billion years, our Milky Way Galaxy may indeed collide with the
Andromeda Galaxy. Unlike the collisions of comets or asteroids with planets,
collisions of galaxies do not usually involve actual collisions of stars in
the two galaxies because of the vast distances between stars, but the strong
gravitational effects could seriously alter the motions of our solar
system. Some calculations indicate that our Sun might be sent sailing toward
the central bulge of our galaxy, where powerful radiation would render our
planet unfit for human habitation.
Of course, the possible collision of the two galaxies is unimaginably far in
the future, but a collision between the Earth and a specific asteroid is of
much more immediate concern. In 2004, the discovery of a 1,000-foot diameter
asteroid, now named Apophis, with an orbit close to Earth's orbit caused
considerable concern when early calculations indicated that it could collide
with Earth on April 13, 2029 with a devastating force of thousands of megatons
of TNT. Later, more precise orbital calculations indicated a very close
approach, within the distance of our own geostationary broadcast satellite on
that date, but no collision. The newest concerns are that the very close
approach could significantly alter Apophis' orbit to put it on a true
collision course with Earth seven years later, in 2036. While the probability
is small, it is the most serious concern to date and many groups of
astronomers are devising strategies for altering this asteroid's (or any
asteroid's) orbit to avoid a collision in the future.
This is the Dudley Observatory Skywatch Line for Tuesday, October 24th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum. Sunrise today was at 7:19 AM, and it set tonight at 6:00 PM. Sunrise tomorrow will be at 7:20 AM, and it will set tomorrow at 5:59 PM. The Moon is currently in a waxing crescent phase today, with the First Quarter Moon on Sunday the 29th. It rose at 9:59 this morning, and set at 6:54 this evening. It will rise again at 11:06 tomorrow morning, and will set at 7:34 tomorrow evening. Watch the moons eastward path in the sky night after night this week. Tonight, it will be very low in the southwest, near the planet Jupiter, about 30 minutes after Sunset. Tomorrow night, it will be near the reddish star, Antares, in the constellation of Scorpius the scorpion. By Friday evening, it will be locate din the constellation of Sagittarius, the Archer. Very low to the horizon during this time of year in the evening, is the famous Big Dipper. It is in the north west sky, and appears upright. Using the end stars of the cup, draw a line upwards, and it will point to the North Star, Polaris, on the end of the handle of the Little Dipper. The Little Dipper is “upside down” compared to the Big Dipper. The Square of Pegasus, also known as the Fall Square, is high overhead by 9 PM The Suits-Bueche Planetarium at the Schenectady Museum will have a grand re-opening celebration on Saturday evening, from 7 – 10 PM, complete with live planetarium programs, music, celestial snacks, and outdoor observing if the skies are clear. The Planetarium will resume regular public programming with our new GOTO Chronos Star machine on Sunday.
This is the Skywatch Line for Monday, October 23. This is Dudley Observatory's Skywatch Line for Friday, October 20, through Saturday, October 21. by Alan French The annual Orionid meteor shower peaks during the predawn hours on Saturday morning. This is a modest shower of meteors that appear to come out of the constellation Orion. It happens when our Earth crosses the orbit of Halley's comet every October and passes through clouds of dust particles left in the comet's wake. You'll want to watch during the hours after midnight on Friday night, through the hours of dawn on Saturday morning. Under dark skies, you may see a dozen or meteors in an hour's time. Keep an eye on the northern and northwestern sky over the weekend. There is a slight chance for northern lights. Weather permitting the Albany Area Amateur Astronomers will host two public Star Parties this coming weekend. At Star Parties a variety of telescopes are set up for your viewing pleasure. During the early part of the Star Party, club members will have their telescopes pointed at some of the celestial showpieces. Later on, we take requests, as long as the object is above the horizon. Star Parties will be held on Friday, October 20, and Saturday, October 21. Both Star Parties are at George Landis Arboretum in Esperance, and begin at 8:00 PM. If you enter Esperance traveling west on Route 20, watch for the arboretum sign on your right, immediately after crossing the bridge over the Schoharie River. After taking the right, follow the signs to the arboretum. Continue up the hill past the main parking area and farmhouse, and turn right into the Meeting House drive as you reach the top of the hill. A reflective "Star Party" sign will mark the driveway. Star Parties are open to all ages and there is no admission charge. There will also be a brief constellation tour near the start of the star party, and participants are encouraged to bring a blanket to sit on. Please dress very warmly – it is easy to get chilled when you are standing under the night sky, and it feels 20 to 30 degrees colder than it does when you are active during the same daytime temperatures. The Star Parties will be canceled if the skies are mostly cloudy. If in doubt, call 374-8460 after 6:00 PM.
Skywatch line for Thursday, Oct. 19, 2006
by Ray Bogucki
The late Summer and Fall seasons are richer in meteor showers than other
times of the year. Two weeks ago we experienced the Draconid meteor shower
but this was mostly washed out by the bright light of the Full Moon. This
week, the major event is the Orionid meteor shower and by good fortune, its
peak occurs at New Moon, when there is no moonlight in the night sky. The
Orionids occur when the Earth passes through the debris left in our orbit by
Halley's Comet. The peak of this shower occurs on Saturday night, but the
meteor stream is very broad and the observing should be good for several
nights before and after the peak. The best time to observe the Orionids is
after midnight when our side of the planet is rushing head-on into anything in
our path. Because Halley's Comet revolves around the Sun in the direction
opposite the Earth's orbital motion, the tiny fragments in the comet's trail
are racing towards us at high velocities and rocket through our upper
atmosphere at speeds of 40 miles per second. Thus, the meteors will appear to
travel very fast and are often quite bright. For best viewing, dress warmly
and go out in the late evening where you can see most of the sky. Sit in a
recliner or lie on an insulated place on the ground facing generally east.
The Orionid meteors may appear anywhere in the sky but they will all appear to
originate from the club in Orion's raised arm near the feet of the Gemini
twins.
Halley's Comet is probably the best known of all comets and has a
fascinating history. In 1705, the astronomer Sir Edmond Halley published his
calculations on many cometary orbits, greatly extending the previous work of
Isaac Newton. He noticed that the bright comets of 1531, 1607 and 1682 were
very similar in their orbital paths and he suggested that they might be the
same comet coming in to revolve around the Sun in a 76-year period. He
predicted that it would reappear late in 1758. Unfortunately, Halley died in
1742, but the comet was spotted on Christmas Eve in 1758 and it was named in
honor of the first person to recognize that some comets are permanent members
of our solar system. Careful study of ancient astronomical records show that
this comet has been observed and reported for at least 30 appearances, back to
240 BC. In ancient times, comets were considered an omen of disaster. This
omen proved true for the Saxons when Halley's Comet appeared in the sky in
1066, just before the Battle of Hastings when the Norman, William the
Conqueror, defeated the Saxons and became King of England.
This is the Dudley Observatory Skywatch Line for Tuesday, October 17th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum. Sunrise today was at 7:10 AM, and it set tonight at 6:11 PM. Sunrise tomorrow will be at 7:11 AM, and it will set tomorrow at 6:09 PM. The Moon is currently in a waning crescent phase today, with the New Moon on Sunday the 22nd. It rose at 2:35 this morning, and set at 4:28 this afternoon. It will rise again at 3:37 tomorrow morning, and will set at 4:45 tomorrow afternoon. Look for the Moon tomorrow morning low in the East southeast about one and a half hours before Sunrise. Just above it will be the star Regulus in the constellation of Leo, and just above Regulus will be the planet Saturn. Very low to the horizon during this time of year in the evening, is the famous Big Dipper. It is in the north west sky, and appears upright. Using the end stars of the cup, draw a line upwards, and it will point to the North Star, Polaris, on the end of the handle of the Little Dipper. The Little Dipper is “upside down” compared to the Big Dipper. By 7:30 PM, the skies are dark enough to see some of the brighter stars. The Summer Triangle of Vega, Deneb and Altair is directly overhead, with the Square of Pegasus, also known as the Fall Square, rising in the north east. Look very low in the west for the planet Jupiter, appearing as a bright star-like object. You will need an unobstructed view of the south west horizon, and you will have to look within a half hour or so after Sunset. The Suits-Bueche Planetarium at the Schenectady Museum, is currently closed, and will re-open again on October 29th. During this time, we are installing the new GOTO Chronos Space Simulator Star Machine. A grand opening celebration is currently being planned for the evening of October 28th.
This is the Skywatch Line for Monday, October 16.
Skywatch line for Thursday, October 12, 2006
During autumn evenings, as the brilliant, blue-white star, Vega,
descends from overhead toward the northwestern horizon, an equally bright,
yellow star climbs into the northeastern sky. This is Capella, the
brightest star in the constellation Auriga, The Charioteer, recognized by a
large, somewhat distorted pentagon of stars. Capella, which translates as
"she-goat", is actually a binary star system in which each star is about
three times the mass of our Sun and many times larger, with a combined
luminosity 160 times brighter than the Sun. They are 42 light-years
distant, and at only 70 million light-years apart, about the distance
between Venus and the Sun, they are too close to be seen separately, even in
a large telescope. Spectrographic studies show that they orbit each other
with a period of 104 days.
The third-magnitude star to the east of Capella in the pentagon is also
a binary system. These two stars, only 7 million miles apart, orbit each
other with a period of 4 days in a plane that is close to our line of
sight. Like clockwork, the light from this pair dims every 2 days as each
star partially eclipses its partner
.
Just southeast of Capella lies a small acute triangle of fainter stars
known as the she-goat's "kids". At the sharp point of the triangle nearest
Capella is the star, epsilon Aurigae, also an eclipsing variable, but one of
the most remarkable and puzzling stars in the sky. The primary star is a
brilliant supergiant possibly 200,000 times more luminous than our Sun, but
at the staggering distance of 7,800 light-years, it appears to us as only
magnitude 3. The most fascinating aspect of this system is that the
eclipsing component is completely invisible in all the usual wavelengths of
visible light, ultraviolet, infrared and radio frequencies. The two objects
orbit each other with a period of 27 years and so, at 27-year intervals, the
light from the primary begins to dim. Remarkably, it takes two full years
for the eclipsing object to complete its passage across the face of the
primary. This must mean that the eclipsing object, if a star, must be the
largest star ever discovered. It has been suggested that it might be a huge
cloud of gas and dust not yet collapsed into a star, or a normal star
surrounded by a large cloud of dust, possibly in the planet-forming stage.
A more recent guess is that it may be a massive black hole which steals some
of the light of the primary star as it passes in front of it. The next
2-year eclipse will begin in 2009 and many astronomers with the latest, most
sensitive instruments will be trying to solve this mystery.
This is the Dudley Observatory Skywatch Line for Tuesday, October 10th, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum. Sunrise today was at 7:02 AM, and it set tonight at 6:23 PM. Sunrise tomorrow will be at 7:03 AM, and it will set tomorrow at 6:21 PM. The Moon is currently in a waning gibbous phase today, with the Last Quarter Moon on Friday. It rises tonight at 8:19, and will set at around 12:50 PM tomorrow. After the Moon occulted the Pleiades last night, it will still be visible near that star cluster tonight. Look for it after 9 PM in the east northeast. By 7:30 PM, the skies are dark enough to see some of the brighter stars. The Summer Triangle of Vega, Deneb and Altair is directly overhead, with the Square of Pegasus, also known as the Fall Square, rising in the north east. Look low in the west for the planet Jupiter, appearing as a bright star-like object. You will need an unobstructed view of the south west horizon. Also very low to the horizon during this time of year, is the famous Big Dipper. It is in the north west sky, and appears upright. Using the end stars of the cup, draw a line upwards, and it will point to the North Star, Polaris, on the end of the handle of the Little Dipper. The little dipper is “upside down” compared to the Big Dipper. In the morning sky, just before Sunrise, look for the planet Saturn. It is visible about an hour before Sunrise in the northeast. The Suits-Bueche Planetarium at the Schenectady Museum, is currently closed, and will re-open again on October 29th. During this time, we are installing the new GOTO Chronos Space Simulator Star Machine. A grand opening celebration is currently being planned for the evening of October 28th.
Skywatch line for Thursday, October 5, 2006
Tomorrow night the Moon will be Full. Whenever the Moon is at Full or New
phase, the Sun and Moon are aligned with the Earth and work in concert to
produce the highest tides of each month. If perigee, the monthly
closest approach of the Moon to the Earth, occurs at or close to the New or
Full phase, the extra gravitational tug of the Moon creates extra high tides.
Last month, perigee occurred just 8 hours after the full phase, producing
extra high tides. This month perigee occurs 13 hours before
Full Moon, still close enough to produce extra large tides. But by next
month, perigee and the Full phase will be far enough out of register that the
effect will be diminished. About nine months from now, perigee will occur
close to the New Moon and we will again experience extra large tides.
On Monday night, The Moon will be passing through the Zodiac constellation
of Taurus the Bull. The ecliptic, the path of the Sun through the stars,
passes through Taurus with the star, Aldebaran, a few degrees to the south of
the ecliptic line and the star cluster, the Pleiades, or the Seven Sisters, a
few degrees to the north. In an 18 year cycle the Moon slowly moves from five
degrees south of the ecliptic in Taurus to five degrees north of the
ecliptic. Several years ago, the Moon was at its southern phase and
frequently occulted the star Aldebaran, the bright red eye of the Bull. Now
it has moved to the northern part of its cycle and occults the stars of the
Pleiades. About midnight on Monday, the Moon will be passing through the
Pleiades and will occult the star Electra, named after one of the seven
daughters of Atlas in Greek mythology. It is always interesting to watch the
Moon's bright edge approaching the star, which appears to sit for a moment
like a tiny bonfire on the Moon's limb before suddenly disappearing. It is
even more fascinating to watch the Moon's darkened back limb where the star
will suddenly appear about an hour later as if from nowhere.
On Sunday evening the Earth will be passing through the densest part of the
stream of cometary debris left in our orbit by the comet, Giacobini-Zinner, a
short-period comet which swings in around the Sun every 6.6 years. The
collisions of its debris particles with the Earth's upper atmosphere generate
the October Draconid meteor shower. This is not a major shower, but worth
watching for. All of the Draconid meteors will appear to originate from the
constellation Draco the Dragon, just west of Polaris, the North Star.
This is the Dudley Observatory Skywatch Line for Tuesday, October 3rd, 2006, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum. Sunrise today was at 6:54 AM, and it set tonight at 6:35 PM. Sunrise tomorrow will be at 6:55 AM, and it will set tomorrow at 6:33 PM. The Moon is currently in a waxing gibbous phase today, with the Full Moon on Friday. It rose at 4:59 this afternoon, and will set at around 3:oo AM tomorrow. Look for the Moon tonight in the south, in the constellation of Capricorn. Watch its eastward motion against the background of stars during the next several nights. By 8 PM, the skies are dark. Look low in the west for the planet Jupiter, appearing as a bright star-like object. The Summer Triangle of Vega, Deneb and Altair is directly overhead. By 9:00 PM, the Fall Square and the Andromeda Galaxy are high up in the east, and by 10:00 PM, the star cluster known as the Pleiades or the Seven Sisters is rising in the same direction. In the morning sky, just before Sunrise, look for the planet Saturn. It is visible about an hour before Sunrise in the northeast. The Suits-Bueche Planetarium at the Schenectady Museum, is currently closed, and will re-open again on October 29th. During this time, we are installing the new GOTO Chronos Space Simulator Star Machine. A grand opening celebration is currently being planned for the evening of October 28th.
This is the Skywatch Line for Monday, October 2 |
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