Skywatch August 2001

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.

 NOTE: Times given in the scripts are all local Schenectady, New York time.

Wednesday, August 1st. Written by Susan French.

The planet Mars is now low in the south during evening twilight. It is the brightest starlike object up at that time and is easily distinguished by its orange color.

Mars has been a disappointing telescopic target for amateur astronomers lately. It is low in the sky where atmospheric effects blur the view, and a global dust storm has enshrouded the planet. For the last few nights, some features have become more apparent on the Red Planet. Is the storm winding down, or is this just a temporary lull? If you have a telescope, keep an eye on Mars and find out.

To the right of Mars, you'll see another orange object - the star Antares. Antares means, "Rival of Mars". The star earned this name for three reasons. First, Mars and Antares sometimes appear near each other in the sky - as they do now. Second, they share a similar color. And third, they sometimes shine with the same brightness. Currently, the Red Planet far outshines its neighbor but Mars varies in apparent brightness more than any of the other planets.

Early risers can see a trio of planets in the east during morning twilight. The highest is Saturn. Although it is in an area rich in bright stars, Saturn is brighter than any of them. More brilliant still is the planet duo of Venus and Jupiter. They will be in the east-northeast, well to the lower left of Saturn. Venus is the brighter of the two.

Venus and Jupiter are now close enough to be viewed together through a pair of binoculars, and they will narrow the gap between them each day reaching their closest approach on Monday morning. At that time, they can share the field of a wide-angle telescope. Binoculars will show Jupiter as a tiny disk and perhaps 3 of its moons. A small telescope will show some dark cloud bands on Jupiter and maybe a 4th moon. Through a telescope, you might also be able to see that Venus shows phases like our Moon. Currently Venus resembles a tiny gibbous Moon, but the planet is so glaringly bright that it is easier to observe after morning twilight begins to dim its luster.

Thursday, August 2nd. Written by Peter Jennes.

  Sunset for tonight, Wednesday, August 2nd, will be at 8:15. The moon is two days away from Augustís Full Corn Moon. At sunset, the Moon will be low in the east and will illuminate the sky throughout the night. Unfortunately, the brightness of the moon will severely hamper observers who hope to spot a few Perseid meteors.

  The Perseid meteor shower has a radiant near Eta Persei, a fourth magnitude star located near the Double Cluster at the northeast corner of Perseus. The peak of the shower occurs on the 12th of August and the normal limits are July 23 to August 20. The meteor stream is associated with Comet Swift-Tuttle. This is one of the best and most reliable annual meteor showers. Peak rates typically range between 50 and 100 meteors per hour. Records of this shower date back 2,000 years.  

The meteors that fall from annual showers like the Perseids rarely strike the ground. These meteors are merely pieces of ice and dust that have been ejected from a comet as it rounds the Sun. Only rarely will one of these pieces be large enough to survive passage through the Earthís atmosphere. For the most part, the meteors in the annual showers are thought to be about the size of a grain of rice. Because of there tremendous velocity, they survive long enough to traverse the sky at high altitudes and in the process become incredibly bright.

  Periodic meteor showers differ from sporadic meteors in that sporadic meteors may be fragments of an asteroid. These bodies are much more solid and therefore stand a much better chance of reaching the ground. These asteroid fragments belong to one of three very general families. The carbonaceous meteors probably are fragments of asteroids that are closely related to comets. The stony meteors are just that, stones that fall >from the sky. Finally, the third general category of meteors consists of iron bodies. These meteors most likely came from the core of some large and ancient asteroid that was broken apart in some ancient collision.

Friday, August 3rd to Sunday, August 5th. Written by John Schroer

The skies over the Capital District are hosting a full moon, the red planet Mars, and now arriving in the northeast, the closest spiral galaxy to the Milky Way, and it is visible to the naked eye stargazer.

Now a month and a half from the start of summer, we are now moving towards the fall, with the sun setting earlier each day. The Sun sets tonight at 8:06 PM, 8:04 PM on Saturday, and 8:03 PM on Sunday.

Tonight also marks the full Moon, with all of the earth facing side of our nearest neighbor in space lit by the sun. Full Moon also marks the half way point of the moonís orbit around Earth. You can locate the Moon in the constellation of Sagittarius, located in the southeastern sky. This will add considerable glow to our skies this weekend, but it does provide a romantic atmosphere for stargazers. The Moon will rise at 8:12 PM tonight, at 8:46 PM Saturday, and 9:15 PM on Sunday. It will be due south at 1 AM tonight, 1:46 AM Saturday, and 2:31 AM on Sunday. This slow movement across the sky will bring the moon closer to the sun each day. By Sunday, the moon will appear in the daytime, setting at 7:47 AM.

Mars, the red planet, is now seen as a bright reddish star in the south by southwest sky, in Scorpius the Scorpion. It will be up in the Capital Districtís skies until a little after 1 AM all weekend long.

Dudley Observatory served all Capital District stargazers with the Dudley Skywatch line, funding for schools to visit the Schenectady Planetarium, and with scholarships available to high school students. For more information on how you can join the Dudley Observatory and support its work, or on how you can apply for a scholarship, call (518) 382-7583, or e-mail dudley at dudley@union.edu. Visit Dudley's home on the web at http://www.dudleyobservatory.com

Monday, August 6th. Written by Joseph Slomka.

The Sun sets tonight at 8:10, with twilight ending at 10:03. Dawn breaks at 4:03 AM and ends with sunrise at 5:53.

As the Sky darkens, the bright planet Mars blazes due South. Even though the Red Planet daily dims and shrinks as it recedes from Earth, Mars is still a worthy object for telescopic observation. An if you only have binoculars, Mars is still interesting as it wanders amid the many star clusters and nebulae of the Scorpius - Sagittarius region.

Dawn skies also provide great binocular views. The mini dipper of the Pleiades never fails to attract attention. Saturn lies below this legendary star grouping. Telescope views of Saturn are always observers' favorites. Binocular views of Saturn and Pleiades are also grand. As the sky brightens, Jupiter and Venus rise virtually together. The lie about one and a half degrees apart. Jupiter is the higher of the pair. Binocular views of Jupiter show it as a ball with four tiny moons. Venus is brightest and appears about three-quarters illuminated.

As Sun sets, the Summer Triangle of the three brightest stars shine high in the East. These stars are part of famous constellations: Lyra, Cygnus and Aquila. There is another, lesser known constellation - Sagitta. Sagitta is Latin for "Arrow," and resembles its namesake. At about 10:00 PM, identify the cross shaped constellation Cygnus, the Swan. A bit south is the bright star Altair in the constellation Aquila, the Eagle. If you look between them, notice a small arrow flying between the two birds. This is Sagitta, the smallest northern constellation, and third smallest in the entire sky. Sagitta 's origin lies in the legendary twelve labors of Hercules - battle with the Stymphalian Birds. The arrow that Hercules nightly launches, misses the Eagle and Swan and sails east. Sagitta contains one major deep sky object, M 71. This is a star cluster located between two stars that form the arrow's tip. This eighth magnitude group is visible in binoculars, but a small telescope displays its true beauty.

Tuesday, August 7th. Written by Jonathan Cassidy.

What is the "W" in the sky? Some of the constellations, or asterisms of stars, are more prominent as they rise in the East. The "W" is made up of the brightest stars of the constellation "Cassiopeia". There are more stars to this constellation but the five that make up the asterism of the "W" are of similar brightness and thus pop out of the twilight at nearly the same time.

Cassiopeia in mythology was the wife of Cepheus the King, Cepheus is a nearby constellation. It is not possible from light polluted cities to find all the stars of a constellation. It is possible to find the brightest stars that make up an asterism in any constellation; such as the "W" in Cassiopeia or the "teapot" in Sagittarius. The Big Dipper is the most famous asterism in the larger constellation of URSA Major.

You can make any group of stars into an asterism with a shape and name that you remember. There is a summer triangle, a winter circle, a spring question mark that is distinct but backwards, in the fall we look for the "Great Square". We use these asterisms to find the constellations and other objects in the night sky.

The "W" in Cassiopeia depicts a chair on which the queen sits. However by the time the chair gets up in the sky you will notice that it is upside down. Cassiopeia sits oh her head. This is fitting as she was said to be boastful. She was made to travel through the night sky this way as reward for her attitude. This attitude also got her daughter Andromeda into big trouble, but that is a story for another time.

Wednesday, August 8th. Written by Ray Bogucki.

Next Saturday night, we should experience the peak of the very dependable Perseid meteor showers. These meteors appear each year at this time when the Earth passes through the debris left by Comet Swift-Tuttle. This comet has been observed and recorded on five successive perihelion passages beginning in the mid-1400's. It appears roughly every 130 years, with the last passage in 1992. In its apparition of 1862, the comet was studied carefully by Italian astronomer, Giovanni Schiaparelli, who calculated its orbit around the Sun. At its closest approach to the Sun, Swift-Tuttle swings just inside the Earth's orbit, before it returns out beyond Uranus. Fortunately, the plane of the comet's orbit lies at the sharp angle of 113 degrees to the plane of Earth's orbit, so it does not linger in our area but passes through quickly.

When a comet nears the Sun, it warms up and huge clouds of gas and water vapor are released from the icy nucleus. As the surface ice sublimes, solid particles of varying size are also released. These particles, ranging in size from dust particles to boulder size, continue to orbit the Sun in roughly the same orbit as the parent comet. It was Schiaparelli's clever observation that the Perseid particles seemed to have the same orbit as Comet Swift-Tuttle that led to our understanding of the relationship between meteor showers and cometary debris.

The debris from a "new" comet will be tightly bunched near the comet, but after many passes, the debris spreads out fairly uniformly over the comet's entire orbit. This is the case with Comet Swift-Tuttle, which explains why we experience a dependable meteor shower each August 12, no matter how long ago the comet has passed through. Actually the path of the debris has widened so that we can observe individual Perseid meteors from late July through all of August, but the central stream of particles, which has a sharply higher concentration of particles, produces the short meteor shower. The best predicted viewing this year should be after midnight Saturday, with the maximum count rate expected in the pre-dawn darkness just before Sunday morning twilight begins. With some luck, a 15- to 20-minute time exposure on fast film in a camera pointed toward Perseus may catch one or more meteors, even though the last quarter Moon will be brightening the sky.

Thursday, August 9th. Written by Peter Jennes.

The moon is now approaching last quarter and does not rise until 11 PM. With the moon below the horizon during the early evening hours, the Summer Milky Way dominates the sky in dark locations. Even if a velvety-black sky isn‚t just outside your door, many of the sky‚s most impressive double stars line the Milky Way and most are visible from almost any location. The constellation Lyra, holds several of these prominent double stars including Epsilon Lyra, the famous "Double-double" star. The Epsilon Lyra system, as its name implies, is composed of four stars arranged in two binary pairs. The pairs of binary stars making up the Epsilon Lyra system are known as Epsilon 1 and Epsilon 2.

The Epsilon Lyra system is easily found about 1.5 degrees to the north of Vega. At this time of year, Vega is the brightest star in the eastern sky during the hours before midnight. If you are looking east towards Vega with your naked eye, Epsilon Lyra looks like a slightly elongated star just to the left and slightly below Vega. Through binoculars or a telescope, the Epsilon Lyra system is easily split into the two pairs. The Epsilon system is 180 light years from Earth and the two binary pairs appear to be a little over three arc minutes apart. At Epsilon‚s distance, this angular separation translates into a real distance of two-tenths of a light year.

Splitting the Epsilon 1 and Epsilon 2 components into the four individual stars requires a telescope working at nearly 100 power. The apparent angular separation of both pairs is just over two arc seconds. For the Epsilon 1 pair, the actual separation is currently about 155 Astronomical Units. The Epsilon 2 pair is slightly wider with the two stars currently about 165 AU apart. The two stars of Epsilon 1 are fifth and sixth magnitude and their combined light yields a magnitude 4.7 object, while the two stars of Epsilon 2 are both fifth magnitude and their combined light yields a magnitude 4.6 object. The Epsilon 1 pair requires 1,165 years to complete one orbit while the Epsilon 2 pair requires 585 years for the same trip.

Friday, August 10th to Sunday, August 12th. Written by John Schroer

Monday, August 13th. Written by Joseph Slomka.

The Sun sets at exactly 8 PM; night falls at 9:49. Dawn breaks at 4:16 AM tomorrow, and ends with sunrise at 6:01.

As the sky darkens, Mars literally occupies center stage; it is found due South at sunset. Mars is gradually growing dimmer and smaller daily. Mars is now in the middle of a rich field of star clusters. The binocular observer need only look two degrees to Mars' right and finds M19 - a rich star cluster. Another two clusters are within nine degrees of Mars. Nightfall finds the Milky Way flowing due South with the Great Square of Pegasus rising out of the northeast.

Pre-dawn and dawn skies feature the giant planets Saturn and Jupiter, with the added attraction of the Pleiades above Saturn in the hours before sunrise. By sunrise, Saturn is highest; the Moon comes next, only a quarter illuminated. Jupiter is in the middle with Venus being closest to the horizon, but also the brightest. Venus appears as crescent, about seventy-seven percent illuminated, to the binocular user.

If we look south at about 10:00 PM, a hazy white band of light seems to stretch from the North Pole to horizon. This band is commonly called "The Milky Way". Examination of the Milky Way with binoculars or telescopes reveals it to be a continuous band of stars or clouds of dust or gases. Our galaxy is a gigantic pinwheel, with several arms. Our planet is located in one of these arms. When we look at the Milky Way, we are seeing through this arm out into space. From Lyra to Sagittarius the Milky Way seems to divide in two. A giant dust cloud causes this "Great Rift". We can see these dust clouds on other galaxies. If we follow the Milky Way to the horizon, we come upon the constellation Sagittarius. The center of our galaxy is located in that constellation, but we cannot see it due to dense star and dust clouds.

Tuesday, August 14th. Written by Jonathan Cassidy.

There is a large nearly square set of stars near the horizon what is it? Star patterns seem larger at the horizon and thus can be more prominent and attractive. This is the Great Square of Pegasus, the horse. This large square can also be seen as a diamond. The sides of this asterism are nearly 15 degrees long each. This arc of sky corresponds nearly to the distance between your extended first finger and pinkie on your out stretched arm.

We can make up another asterism from this group of stars. This is the season of baseball and I see a baseball diamond here. If you look carefully under a dark sky you can see some of the ball players. The star furthest to the West has another even further west near it. This is the catcher and umpire and marks home plate. To the East at the opposite end of the diamond we find second base. Between these two we find two dim stars that represent the pitcher and the manager talking. They are not in the center where the mound is because the pitcher is being replaced. To the north and south stars have other nearby stars that can be seen as representing first and third bases coaches.

The first base star and the next star to the north are of the constellation Andromeda and with them you can find the Andromeda Glx. later in late August through December.

Wednesday, August 15th. Written by Ray Bogucki.

Early risers tomorrow will be rewarded with a fine conjunction of Venus and the Moon in the eastern sky before sunrise. The waning crescent Moon slipped just below Jupiter near moonset this afternoon, and will travel the 10 degrees between Jupiter and Venus overnight to stand about 3 moonwidths above and to the left of Venus early tomorrow morning. By noting carefully the relationship between the Moon and the brilliant planet, you should be able to find Venus with the unaided eye even after sunrise. Using the Moon as a reference point and remembering that the Moon will move about one moonwidth further to the east of Venus each hour, you should be able to impress your friends by locating Venus throughout the day with your unaided eye or, more easily, with binoculars.

In the evening sky, the three stars that form the "Summer Triangle" float high overhead. The brightest star, Vega, shines close to the zenith. Deneb at the head of the Northern Cross, lies about 20 degrees northeast of Vega, while Altair in Aquila, the Eagle, lies 30 degrees south of Vega. At only 16 light-years distant, Altair is the third nearest of the bright stars visible from this latitude. Altair is about one-and-a-half times the size of the Sun and 11 times as luminous. When astronomers studied the spectrum of Altair, they found that the normally sharp spectral lines of various elements were greatly broadened. This was interpreted to mean that one limb of the star was approaching us at a speed of over 150 miles per second causing a corresponding blue shift of the lines while the opposite limb was receding at the same speed, causing a red shift. Calculations showed that Altair must have a rotational period of only six hours, about 100 times faster than the rotation of our Sun. This rapid rotation would cause an extreme bulging or flattening at the equator, giving the star an ellipsoidal shape much more flattened than that, for example, of Jupiter.

Thursday, August 16th. Written by Peter Jennes.

The constellation Lyra holds several prominent double stars including Beta Lyra, the prototype for one class of eclipsing variable stars. You can find Beta Lyra by looking for Vega. Vega is the bright star nearly directly overhead after 10 PM. Hanging below Vega lies a dim parallelogram of four, third and fourth magnitude stars spanning five degrees of sky. Because these stars are relatively dim, you may need binoculars to see them clearly under light-polluted urban skies. Once you have found Lyra's parallelogram, start with the corner star nearest Vega. This star, Zeta Lyra, is two degrees away from and directly below Vega. Proceeding clockwise around the parallelogram, Beta Lyra occupies the next corner about four and a half degrees away from Zeta Lyra.

Beta Lyra is also known by its Arabic name, Sheliak. It is the prototype for "Lyrid" eclipsing variable stars. Beta Lyra and all variable stars in this class are composed of two massive stars orbiting very close to each other. The two members of these systems are so close that the individual stars cannot be seen. However, spectroscopic studies of Beta Lyra indicate that these variable stars have egg shaped components and that mass flows from one star to the other. Some of this material is lost to space, forming a vast spiral sheet of gas and dust around the binary system.

Beta Lyra eclipsing variable stars also orbit each other very rapidly. In the case of Beta Lyra, the orbital period is about thirteen days. Because Beta Lyra has a chance alignment with Earth, we see two eclipses during each orbit of the binary pair. During each eclipse, the light from the binary pair varies. When both stars are perpendicular to the Earth, we see their combined light and Beta Lyra seems relatively bright. When the brighter star eclipses the dimmer star, Beta Lyra seems to be slightly dimmer. Then, when the dimmer star eclipses the bright star, Beta Lyra is at its dimmest. These eclipses have a regular cycle and the light coming from all Beta Lyra variables follows a characteristic curve where the maximum brightness is reduced at two points showing different minimum values. By comparing Beta Lyra to nearby stars, you can follow these changes using binoculars or the naked eye.

Friday, August 17th to Sunday, August 19th. Written by John Schroer

Monday, August 20th. Written by Joseph Slomka.

Tuesday, August 21st. Written by Jonathan Cassidy.

Double stars with a distinct difference in color are good to find and observe. The star known as Alberio is one of these. It is visible to the naked eye and the two parts that make up the single point of light can be separated by a small telescope.

The two stars are said to be of blue-white and orange-white hues. When observing most people new to astronomy can see a difference between these two. There are other more dramatically colored pairs of stars such as Iota Cancer, but we have Alberio up tonight.

Like all stars that begin with "AL" the name is ancient, but of unknown origin. To find it look directly overhead once the sky is dark. The brightest star near the zenith of the sky is Vega. The next bright star to the East is Denab. There is a line of star extending from Deneb toward the South. This line marks the body of Cygnus the Swan with Deneb as the tail and Alberio as the head four stars down the line. The stars are of varied brightness so you will need a dark sky to locate them.

Alberio is visible to the unaided eye as a single point of light. It is only with binoculars or telescope that we can see that indeed there are two stars there and they are not the same. The blue-white star is burning hotter than the orange one.

Wednesday, August 22nd. Written by Ray Bogucki.

High overhead in the late evening sky, Cygnus, the Swan, flies south along the Milky Way. Its most easily recognized asterism, the "Northern Cross", lies embedded in the Milky Way along the galactic equator. At the top of the cross, the star Deneb shines brightly despite its staggering distance of 1600 light-years, because it is a magnificent giant of a star, 25 times more massive than the Sun and 60,000 times more luminous. About 3 degrees east of Deneb, a bright nebula is rendered luminous by Deneb's powerful radiation. This foggy patch of light is known as the North American Nebula because of its distinct shape. The outlines of the North American continent are formed by dark clouds of intervening dust that obscure the light from the glowing gas. In a dark sky, binoculars will show a definite hint of the shape, while a 10-minute guided exposure with a camera using ordinary high-speed color film will show the shape clearly in a red color.

At the bottom of the cross, the third magnitude star Albireo is considered by many to be the most elegant double star in the northern skies. The bright golden-yellow star has a fainter, distinctly blue companion, 34 arc-seconds away. The striking color difference is even more apparent if the telescope or binoculars are slightly out of focus.

About 6 degrees northeast of the easternmost star in the crossarm lies a faint star barely visible to the naked eye which carries the designation 61 Cygni (SIG-nye). While visually unimpressive, 61 Cygni is of great historical significance. In 1792, Piazzi discovered that this star was moving at the abnormally high proper motion of 5 arc-seconds per year against the background of fixed stars, and named it the "Flying Star". This motion was clear proof that the so-called fixed stars are not "fixed" at all. Later, in 1838, Bessel, assuming that the rapid apparent motion indicated that the star was relatively close to the Sun, made the first successful application of the parallax method for measuring the distances of stars by trigonometric means. Working at the limits of instruments at that time he measured a parallax of 3 tenths of an arc-second which indicated a close distance of about 10 light-years, a remarkable accomplishment. He would probably be astonished that, today, the Hipparcos satellite routinely measures parallaxes of one thousandth of an arc-second.

Thursday, August 23rd. Written by Peter Jennes.

The Summer Triangle is now high in the east and tucked inside lies Sagitta the Arrow. Although Sagitta's four brightest stars are only third and fourth magnitude, it is easily found because of its distinctive shape. To find Sagitta, begin with the Arrow's tail feathers. Sagitta's tail feathers are two equally bright stars ten degrees above the lower right hand star in the Summer Triangle. Sagitta's other two bright stars lie to the north on a short line perpendicular to the tail feathers.

Three noteworthy deep sky objects surround Sagitta. These objects are an open cluster, a globular cluster, and one of the best planetary nebulas. The open cluster, Collinder 399, lies in Vulpecula. However, you can use the Arrow's tail feathers to find this cluster. Look about one binocular field above and to the right of the top tail feather. Collinder 399 looks like an upside down hanger which leads to the clusters common name, the Coathanger. The hanger's bar is a straight line of six stars while the hook is a tight curve of four stars protruding from the middle of the bar. The Coathanger covers more than one degree of sky and shows up best in binoculars.

Sagitta's globular cluster lies midway between the two stars forming the Arrow's shaft. Until recently, M71 proved difficult to define. Visually, M71 is quite dim and looks like a very dense open cluster or a very sparse globular cluster. Also, because several types of stars that characterize globular clusters are in short supply and because many of the stars present are rich in metallic elements, M71 did not seem to be a globular cluster. However, in the 1970's, photometric measurements proved M71 was a very young globular cluster.

Like the Coathanger, the bright planetary nebula near Sagitta is also in Vulpecula. After leaving M71, move left and stop when you come to Sagitta's fourth bright star. Look one binocular field above and to the left of this end star. The nebula, M27 will be a ghostly green glow. In a telescope, M27 is quite bright and nearly one-fifth the size of the full moon. Portions of the nebula are brighter than others giving M27 a distinct shape that leads to M27's name, the Dumbbell Nebula.

Friday, August 24th to Sunday, August 26th. Written by John Schroer

The skies over the Capital District will be bright, thanks to the moon and the red planet, Mars. The skies to the south will feature the first quarter moon, which will be due south at 5:59 PM on Friday, 6:46 PM on Saturday, and 7:38 PM on Sunday. Through a small telescope,an observer using high power can see light and dark areas or the hint of a polar ice cap. More details can be viewed with larger telescopes, or through the internet at NASA's Jet Propulsion Labs web site, at http://mars.jpl.nasa.gov.

The Moon will reach first quarter during this weekend, so half of the lunar side facing earth will be lit by sunlight. The creeping line of dawn moving across the surface of the moon is moving to the left, as is the Moon each day. By next weekend, the Moon will be half way round its orbit of the earth, marking the Full Moon.

The Union College Observatory is hosting a Open House Saturday evening, August 25th, from 9 PM to 10:30 PM. Please take the Van Vranken entrance into the campus, and walk to the Olin Center, next to the Student Union.

This has been Skywatch Line for Friday, August 24th through Sunday, August 26th. For more info on Dudley Observatory, visit our web site at www.dudleyobservatory.org

Monday, August 27th. Written by Joseph Slomka.

The Sun sets tonight at 7:38 PM, while night falls at 9:20. Dawn breaks at 4:36, and sunrise takes place at 6:16.

As the Sun sets, the Moon and Mars are found together in the South. Mars is about five degrees below the Moon. The Moon's brilliance blots out most deep sky objects, but solar system members are easily seen. Mars is still very bright and big. Even in binoculars Mars is obviously a round ball , not a star's pinpoint. Mars is definitely smaller than it was about two months ago, but still worth observing. When the Moon is absent from Mars' vicinity, Mars will be in the company of many impressive galaxies, star clusters and glowing gas clouds.

Pre-dawn skies also feature bright planets. Saturn is highest. The ringed planet is about fifteen degrees below the lovely star group, the Pleiades, which is a worthy binocular object in its own right. While one cannot see Saturn's rings in ordinary binoculars, Jupiter's four moons are easily observed. Venus is the lowest of the trio, and also an interesting object. In powerful binoculars, one can see that the planet is a crescent about as fat as the Moon is, about 81 per cent illuminated.

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. A complex satellite system is Jupiter's other attraction. There are 28 moons, of which four are visible to small telescopes and binoculars. However, Jupiter may have lost the satellite sweepstakes. A recent survey of Saturn reveals that the ringed planet has 30 satellites. A similarly detailed study of Jupiter may put it back in first place.

Tuesday, August 28th. Written by Jonathan Cassidy.

Where is the Andromeda Glx? We often hear this asked in the spring and early summer. The time for the Andromeda Glx. is now!

Many visitors to star parties have heard of the Andromeda Glx. They've been told to look for it as it should be visible from a dark sky location. Only they want to see it in seasons it is not up, and as in true of all the wonders of the night sky it is available to be seen only during its own season. That is when the night side of Earth is pointed in that direction.

Now, however, is the time to start looking for this galaxy in the night sky above the horizon. September is the season of Andromeda. To find it look to the East after dark and find a large nearly square asterism of similar brightness stars. It may look like a baseball diamond.

From the North most star follow a trail of stars in a slow arc going to the north. There is a relatively bright one at the corner of the square then a dim one and another similar bright one. At the third star, the one of similar brightness to the first, turn right or West. Go two dim stars out this line. If you can see these two dim stars you will notice a bright patch to the South West of the second one -This is the Andromeda Glx.

Wednesday, August 29th. Written by Ray Bogucki.

Last week's Wednesday Skywatch line described several objects in Cygnus the Swan, marked by the well-known "Northern Cross", including giant Deneb, colorful Albireo, the North American nebula and the "Flying Star". Among the many other fascinating objects worth noting are several variable stars. P-Cygni is an unimpressive-looking star, lying about 3 degrees south of the center star of the Cross, and barely visible in a dark sky. It was classified as a nova when it first appeared in 1600 as a 3rd magnitude star. It faded away in a few years, but reappeared several times over the next century at very irregular intervals. For almost 3 centuries now, it has remained near magnitude 5. Spectroscopic studies suggest that this is a most extraordinary star at the incredible distance of about 6,000 light-years. It is much more massive and brighter than even Deneb and Rigel, almost a million times brighter than our Sun. It is highly unstable and could flare up again at any time. It will most likely end its short stellar life in a brilliant supernova explosion.

A much more regular variable star designated as Chi (KYE) Cygni lies further down between the 3rd and 4th stars in the vertical bar of the cross. As its faintest, this star is below 14th magnitude but every 407 days it brightens to almost 3rd magnitude, rivalling the two end stars in the crossarm. It is noticeably red in color and is one of the strongest infra-red sources in the sky.

Perhaps the most mysterious object in Cygnus is Cygnus X-I, one of the strongest X-ray emitters known. Precise measurements show that the position of this object coincides with a visible, massive blue star of 9th magnitude. Spectroscopic studies reveal that the invisible X-ray emitter and the visible star orbit each other with a period of 5.6 days, and that the unseen object has a mass equal to about 10 solar masses. Since the X-rays flicker with a period in the millisecond range, the object must be very small, perhaps only a hundred miles in diameter. The best current explanation for its immense mass and tiny size seems to be that Cygnus X-I is a black hole. As matter is pulled from the companion star by the powerful gravity of the black hole, it reaches high speeds and temperatures that cause it to emit X-rays before it disappears forever into the black hole.

Thursday, August 30th. Written by Peter Jennes.

Friday, August 31st to Sunday, September 2nd. Written by John Schroer

Sky watchers of the Capital district will have a bright sky to observe during this last weekend of summer, with a planet and a full moon to view.

This brightening of the evening and night sky is due to Earth's closest neighbor, which is the Moon. It will reach Full Moon Phase on Sunday. Known to farmers as the Harvest Moon it takes a long path across the southern sky. This permits farmers to harvest their crops late into the night, working by the light of the Moon. Other names for the September Full Moon include the Chrysanthemum Moon by the Chinese, the Nut Moon by the Cherokee, the Mulberry Moon by the Choctaw, Singing Moon by the Celtic peoples, and the Barley Moon by the medieval English. On Friday the Moon will rise at 6:54 PM; while on Saturday the Moon will rise at 7:25 PM. The Moon will rise on Sunday at 7:51 PM.

Only one planet is visible to earthlings in the late summer sky. It can be spotted in the southwestern sky as a bright reddish light. Mars, the Red Planet, is now in the constellation of Sagittarius the Archer. Most sky watchers recognize this constellation as a teapot, with Mars just above the spout. Mars is located due south at 7:58 PM on Friday, reaching due south two minutes early on Saturday, and again on Sunday. It will set around midnight during the Labor Day weekend.

The zenith or top of the sky is filled with many bright stars as the Summer Milky Way rises higher with each passing night. Look for the brightest one with a suggestion of blue in its light. Named Vega, it is the brightest summer star and is found in Lyra the Lyre or Harp. It is 27 light years away, or approximately 162 trillion miles from Earth. The rest of the constellation Lyra appears as a parallelogram or slight tilted rectangular box made of fainter stars than Vega. The fall stars are now making their presence known as they rise in the eastern sky over the Capital District. Due east, and just above the eastern horizon is a box of four bright stars. Knows as the Great Square of Pegasus, they mark the body of the flying horse, friend to Perseus the hero.

The Albany Area Amateur Astronomers is an active group of hobbyists that explore the universe for the fun and excitement of exploration and sharing a common interest in the skies above. Anyone interested in exploring astronomy as a hobby should call Alan and Sue French at (518) 374-8460, or call the Schenectady Museum at (518) 382-7890 for further information

You can find more information on the night skies by staying in touch with the Dudley Observatory Skywatch line or by visiting the Dudley Observatory web site at http://www.dudleyobservatory.org. Skywatch Line is Open Daily after 5 PM Monday through Friday.

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Dudley Observatory
107 Nott Terrace, Suite 201
Schenectady, NY 12308
(518) 382-7583
info@dudleyobservatory.org