Skywatch June 2002

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.

Friday, May 31st to Sunday, June 2nd. Written by George Mileski

The moon on Friday is a waning gibbous moon. On Sunday it will be a last quarter moon. As far as stargazing is concerned, the moon will be rising well after midnight, so its light will not be a factor. In the west Jupiter and Venus are drawing closer together. On June 3rd they will be 1.7 degrees apart, there closest approach. Below Venus and to the right, is the planet Mars. It will be visible during June, but will be very low in the western sky. Venus, Jupiter and Mars are in the constellation Gemini, right above them are the brightest stars in Gemini, Castor and Pollux, known as the twins, the twins are in the zodiac where the moon and planets travel. Two out of nine planets were discovered when passing through the twins, Uranus in 1781 and Pluto in 1930.

Rising in the east are the stars of the "summer triangle", this is not a constellation but an asterism. The three stars are Vega, a zero magnitude star, northeast of Vega is Deneb and east of Deneb is Altair, if you have a nice dark sky and you can trace out the Milky Way, you will see that it goes right through the summer triangle. There are five constellations in or near the summer triangle. Aquila, the Eagle, its brightest star is Altair, Altair is yellowish-white, its only about 16 light-years away. Altair rotates very fast, once every 6 hours, compared to our suns 25 day rotation. This rapid rotation tends to flatten it and give it an ellipsoidal shape.

Another constellation is Lyra, the lyre, in the shape of a parallelogram with its brightest star Vega. Vega lies at the Milky way's western border. In the eastern part of the summer triangle, near Altair is a small constellation called Sagitta, the arrow. The stars are kind of dim, but you will see the arrow points northeast. The next constellation is Cygnus the swan. The brightest star is Deneb, which is the tail of the swan, Albireo is the head, Albireo is a beautiful binary star, with the colors of yellow and blue. Also located in the stars of Cygnus is the "northern cross", the stars are an asterism. The last constellation is Vulpecula also known as "the fox" is a small constellation with very dim stars. Its claim to fame is a planetary nebula known as "the dumbbell nebula".

Monday, June 3rd. Written by Joseph Slomka.

The Sun sets tonight at 8:29, with twilight ending at 10:41 PM. Dawn breaks at 3:06 AM, and ends with sunrise at 5:18.

As the western sky darkens, two pairs of bright objects shine moderately high. The brightest pair is Venus and Jupiter &endash; two planets. Venus is brightest and to Jupiter's upper right. They are separated by less than two degrees and easily occupy the same binocular view. The great springtime planetary alignment is ending, but it is still fascinating to note Jupiter and Venus' nightly positions, as Venus climbs higher and Jupiter slides lower. The other bright pair is the stars Castor and Pollux, the bright twin stars of Gemini.

By 8:30 PM, the constellation Gemini, The Twins rides high in the West. Locate two stars that seem equally bright; tonight's pairing of Jupiter and Venus, just below, make identification a snap. The constellation indeed resembles stick drawings of men. Castor is the northern and slightly dimmer star; Pollux is his brother. Castor was an expert horseman, while Pollux was a boxer. Their names reflect these occupations. They were sons of the Greek god Zeus, and Helen of Troy's brothers. Greek sailors revered them as protectors. The phrase "by jimminy" is a variation of "by Gemini," an ancient oath. The Chinese considered these stars as representatives of Ying and Yang, opposing forces that control the universe - light and darkness, male and female. The equally bright stars symbolized the equilibrium of these ` contrasting aspects of nature. Castor is itself a multiple star system, involving six stars. Some of these stars are visible in amateur telescopes, others are not. In fact, Castor was the first star to be recognized as a true binary, two stars revolving about a common center. The star is about 45 light years distant and about 36 times brighter than our Sun. Pollux, traditionally designated "beta," is slightly brighter than Castor. The Twins may have changed in brightness since classical times. Pollux is 35 light years distant and about 35 times brighter than the Sun.

Tuesday, June 4th. Written by Jonathan Cassidy.

Closest approach of Venus and Jupiter this week. We will find these planets low in the west shortly after sunset. They will be the brightest objects in the sky just above and a little to the south of where the sun goes down.

You will see them each night this week pull away from each other. Venus, being closer, is traveling faster in our sky than Jupiter. From our view Jupiter is moving at nearly the same pace as the back ground stars.

At this time Jupiter is near the opposite side of the sun from us. Venus is on the same side of the Sun as we are. This is a very large distance. Because of this difference Venus will look significantly larger and have a crescent shape where as Jupiter will be disk like.

To see Venus as a crescent, like our moon, is not common. On Thursday of next week, Thur. after next, we will be able to find Venus and the Moon with similar crescent shapes very near each other. Take out your binoculars and note this similarity.

Wednesday, June 5th. Written by Ray Bogucki.

The spectacular alignment of the five bright planets has dissipated. Both Mercury and Saturn have disappeared into the Sun's glare and Mars will soon join them. Only the two brightest planets, Venus and Jupiter, remain in an elegant pairing low in the west in the early evening.

Higher in the western sky is the Zodiak constellation, Leo the Lion, easily recognized by its patterns of a backward question mark, or sickle, with a bright triangle of stars to its east. A few weeks ago, the Wednesday Skywatch line discussed three stars in this constellation and the relationship between each star's luminosity, distance and apparent brightness. Before Leo disappears into the evening twilight, we can take one last look at twol other interesting objects in this ancient constellation.

First magnitude Regulus is the brightest star in Leo and lies at the bottom of the handle of the sickle. Just above Regulus at the junction of the handle and blade of the sickle sits eta Leonis, much larger and more luminous than Regulus, but shining at a fainter third magnitude because of its great distance of 2,000 light-years. The next star in the curved blade is second magnitude Algeiba (al-JEE-bah), or Gamma Leonis. A small telescope shows that this is a double star, with a separation of 5 arc-seconds, considered by many as the most beautiful pair in the sky. The two golden stars are a true binary system orbiting their common center of gravity with a period of 619 years. Their orbital motions are currently carrying them further apart in our line of sight.

About 5 degrees west of Regulus lies a famous red variable star designated as R Leonis. This is an unstable, dying, giant star which undergoes alternate swelling and shrinking in a 312-day cycle that causes it to vary from fifth to tenth magnitude. Lying at a distance of 600 light-years, it is an egg-shaped supergiant with a large dimension of almost a billion miles. It is currently well below naked eye visibility, but in the early morning sky next December, you may catch a glimpse of this fiery red giant when it is at its maximum brightness and just visible to the naked eye in a dark sky location.

Thursday, June 6th. Written by Peter Jennes.

As darkness spreads across the Capital District, almost all the stars that you see belong to a group called Population 1. Population 1 stars are usually found within the galactic plane, especially the spiral arms. As you move towards the galactic center, stars tend to be older and belong to another group of stars known as Population 2. W. Baade, who introduced these two groups in 1944, first made the distinction between Population 1 and Population 2 stars.

Typical Population I objects are young, hot, main-sequence stars. These stars also contain abundant heavy elements because the materials from which they formed were enriched with materials ejected from supernovas and other dying stars. In contrast, Population 2 stars contain few elements heavier than helium. This lack of heavy elements is most easily explained if Population 2 stars formed before our galaxy collapsed into its present structure and before the interstellar medium was enriched with heavy elements created by dying stars.

Another difference between the two population groups is that Population 2 stars are relatively old and occupy a spherical halo around the galactic center instead of inside the spiral arms like Population 1 stars. Because Population 2 stars belong to the galactic halo, their orbits around the galaxy are very elliptical and highly inclined to the galactic plane. This orbital track speeds Population 2 stars along at a very high rate in relation to the Sun and other stars in the galactic disc.

Arcturus is one of the most prominent Population 2 stars. Like other Population 2 stars, Arcturus has a highly inclined orbit. This orbit has brought Arcturus within 36 light years of our Solar System and makes Arcturus' prominence in our night sky only temporary. Our sun and Arcturus are passing like ships in the night and in 500,000 years, Arcturus will fade into the galactic distance. To find this galactic wanderer, look for the Big Dipper's handle and then extend the arc away from the Dipper. The first bright star you come to is Arcturus. Another Population 2 star is Groombridge 1830 in Ursa Major. Groombridge 1830 is moving so fast, that it is known as the Runaway Star. In 100,000 years this speeding star will move across the sky to a position well south of Scorpius.

Friday, June 7th to Sunday, June 9th. Written by George Mileski

As we know there would be no life on earth without the sun. It provides the energy that makes life possible, the sun is so commonplace in day-to-day life that people take it for granted. But did you ever wonder if the sun will ever die. Some day the sun must run out of fuel, so some day it will die. Without the energy and warmth of the sun, life on earth would be impossible. The oceans would freeze, and so would the air. But what will actually happen is the sun will swell up and take the form of a red giant star. It will look enormus, and it will fry the oceans. So the oceans will actually evaporate before they have a chance to freeze.

At this point the energy received from the swelling sun will be so great, all life (if people still exist), will die. The red giant sun will puff off its outer layers, forming a beautiful expanding nebula. At this stage to Astronomers, our sun would be called a planetary nebula. But no one will be on earth to admire it. The nebula will gradually clear away and all that will be left at its center is a tiny cinder of the sun. A hot little object called a "white dwarf star". It won't be much larger then earth. Although it will be pretty hot, it will be so small that it will cast little energy on earth. So whatever's left on earth will freeze, and the white dwarf will just be shining like the embers of a campfire, it will slowly fade away. This all sounds kind of dismal, but it might be 5 billion years before we have to worry.

In the sky tonight and over the weekend, we have a waning crescent moon. The moon will be new on the 10th. In the west, we still have three planets to look at. Venus and Jupiter are a brilliant sight and they are slowly separating a little everyday, Jupiter getting lower to the horizon. Mars is low on the horizon and hard to see, you need binoculars. Comet Ikeya-Zhang is in the constellation Serpens, near the serpent's head. Even with binoculars its kind of hard to see, but you can see it, believe me. ON Sunday the 9th at 10:18 pm from the NW, you'll be able to see the International Space Station, it will pass almost directly overhead.

Monday, June 10th. Written by Joseph Slomka.

The Sun sets at 8:33, with night falling at 10:48PM. Dawn breaks at 3:01 AM, and ends with sunrise at 5:16.

As the Sun sets, only the bright planets Venus and Jupiter are visible in the western sky. Both planets occupy the constellation Gemini, and easily outshine the main stars, Castor and Pollux. Venus is the brightest and is seen first; Jupiter follows to Venus' lower right a few minutes later. Mars is also up in the sky, but so close to the Sun that the Sun's glare overwhelms the tiny planet.

Venus appears as partially illuminated, about seventy-eight percent. It will not appear very clearly in your telescope, because its low altitude permits the atmosphere to distort its image. The same applies to Jupiter. The planet is even lower. If you observe Jupiter with binoculars, it still appears as a ball. However, telescopic views show it as a ball, with cloud bands, but no visible satellites. Jupiter appeared in the news this week for two reasons. The first item announced that Jupiter eclipsed Saturn as the planet with the most moons &endash; thirty. The second report revealed that Io, one of Jupiter's moons, is the most volcanic in the Solar System. The Galileo space probe revealed that Io possesses 120 volcanoes on a body only slightly larger than our Moon.

The Sun and Moon occupied the attention of people in the central Pacific Ocean. Today, an annular eclipse of the Sun took place. It could be observed from Indonesia to the western US. Because the Moon's obit is not exactly circular, it appears as slightly larger or smaller than the Sun. The eclipse is called annular, because the Moon does not completely hide the Sun; it is a bit too small. As a result, it blacks out the Sun's center, and leaves a "ring of fire." Later on, in December, the Moon will completely block out the Sun for a total eclipse, which will cross southern Africa, the Indian Ocean and end in the Australian outback.

Tuesday, June 11th. Written by Jonathan Cassidy.

This week the sky at night is dark because the moon is near new. When the moon is new it appears in our sky during the daytime. Absence of the moon at night leaves the sky very dark.

Shortly after the sky darkens you will find the bright star Arcturus is near the top of they sky. Arcturus is the brightest star of the constellation Bootes, the heardsman. Half to the horizon in the east is another bright star, this is Vega, the brightest star of the constellation Lyra.

Look between these two stars and find two other constellations. One third of the way from Arcturus to Vega is a crescent pattern of stars, some might see this as a horse shoe. It is Corona Borealis, the northern crown. In dark skies one can see all the stars of this constellation that form the "crown" shape. If the moon were up we would not be able to see many of the dim stars.

Many cultures saw this same set of stars and called it different things: Arabs saw a broken dish; for Australian aborigines it was a boomerang. It has long been known as the Crown of Ariadne. It was Ariadne who saved Theseus from the minotaur in the maze on Crete. She later married the Greek god Bacchus though she was human. When she died Bacchus honored her by putting her crown among the stars. ("Crown of Ariadne" legend is from 365 Starry Nights, by Raymo)

Wednesday, June 12th. Written by Ray Bogucki.

This past Monday, the New Moon was in a direct line between Earth and the Sun. This alignment produced a solar eclipse which was not total because the Moon's disk was not quite large enough to completely cover the Sun. More than half of all solar eclipses are of this type, called annular eclipses. At the moment that the center of the Moon and the Sun are exactly aligned, a thin ring of sunlight remains surrounding the edge of the Moon. Although many of the spectacular aspects of a total eclipse are absent from an annular eclipse, it must have nevertheless been fascinating for observers on Mexico's west coast to see the Sun setting as a thin fiery ring. Observers in western and central U.S. saw the event as a partial eclipse, with the Moon taking a "bite" out of the Sun's disk. Unfortunately for our area, the eclipse began just after the Sun set.

Tonight the new crescent Moon lies just to the right of Jupiter an hour after sunset, and tomorrow evening, the growing crescent will shine just above the brilliant planet Venus.

The earliest sunrise of the year occurs this Friday, nine days before the longest day, the summer solstice, on June 21. The latest sunset doesn't occur until June 27, six days after the solstice. This asymmetry between the earliest sunrise and latest sunset is caused by the tilt of the Earth's rotational axis to the plane of the ecliptic and the elliptical nature of our orbit around the Sun. It is always interesting to recall that our elliptical orbit carries us to our farthest distance from the Sun, 94 and a half million miles, where we receive the least energy from the Sun, on July 6, during our warmest season of the year.

Thursday, June 13th. Written by Peter Jennes.

After 11 PM, the Milky Way arches across the sky from the Teapot of Sagittarius in the southeast through the Summer Triangle in the east. As you scan this region, you may notice several misty, cloud-like patches called nebulae. In fact, the term "nebula" comes from the Latin word for cloud. Nebulae belong to one of two very general categories. Essentially, nebulae are associated with either the birth or the death of stars.

Regardless of which category the nebula belongs to, all nebulae are accumulations of gas and dust. For the most part, these clouds of material shine by either light from within the cloud or from light originating outside the cloud. Nebulae that shine by light from within the cloud are called emission nebulae. The light that illuminates these clouds comes from stars giving off intense ultraviolet light that cause the cloud to glow. Since young stars ooze ultraviolet light and they are being born amid vast clouds of gas and dust, young star clusters are often associated with diffuse emission nebula.

Sometimes, the nebula material is so thick that light from inside the cloud can’t penetrate the cloud. If there are stars in front of the cloud, light from the stars bounces off the cloud and create a reflection nebula. If the cloud is thick enough to stop the light from inside the nebula and if there are no foreground stars to create a reflection nebula, the cloud will look like a "hole" in the Milky Way. These nebulae are called absorption or dark nebula.

Nebulae associated with dying stars are either planetary nebulae or supernova remnants. Planetary nebulae form when normal, sun-like stars slowly burn out their nuclear fuel. During this process, these stars puff off shells of material until only the stellar core remains. The core gives off intense ultraviolet light causing the shells to fluoresce. Supernova remnants on the other hand form in the cataclysmic death of massive stars. In one brief instant, the star’s core collapses and the star explodes spewing out a cloud of material. Shock waves traveling through the cloud and the compressed matter remnant of the core give off intense fields of electrons that illuminate the remnant cloud with synchrotron radiation. With binoculars and patience, you should be able to find examples of all nebula types in the Milky Way.

Friday, June 14th to Sunday, June 16th. Written by George Mileski

As much as 85% of stars are double or multiple star systems, our sun being a single star is in the minority, its light output remains stable over long periods of time. For thousands of years the sun has not varied from its present brightness by more than one percent and most other stars are similiarly stable. However a few stars are passing through critical stages in their evolution, where there thermonuclear generators are shifting from one type of fuel to another. What happens at this stage varies from star to star, depending mostly on a stars mass, but some stars undergoing this transition can oscillate in brightness by a factor of 15,000 in a span of just one year. 

These are called variable stars. Astronomers are keenly interested in these variable stars, understanding them may reveal considerable information about stellar evolution and about the onset of death among stars, since many variable stars appear to be nearing the end of their lives.  

There are four main classes of variable stars, the first is called a Cepheid variable, named after the prototype Delta Cephei, in the constellation Cepheus, they are highly regular pulsating stars. There period of variability and there range in brightness are so precise that they are used as the "standard" to determine the distances to galaxies beyond the Milky Way. 

Eclipsing variables are binary systems in which neither star varies but there orbits alternately place one star in front of the other, thus producing an eclipse and a decrease in light. The star "Algol" in Perseus is an example of this.   

Long-period variables are red giants similiar to Betelgeuse and Antares, but at a different stage in their evolution. Some of them vary by more than 10 magnitudes in less than a year. They are interesting because of the unpredictability. Mira in the constellation Cetus is an example of a long-period star. 

Irregular variables are the final type of easily observed variable star and include a variety of oddball stars, some that are normally bright and then become dimmer and others that are faint and occasionally brighten. Another group oscillates over months or years brightening or fading by a few tenths of a magnitude. Betelgeuse in the constellation Orion is in this category.  

On Friday the 14th in the west you will find the crescent moon in a line with Venus, Jupiter and Mars. Venus which a few weeks ago was below Castor and Pollux, is now almost lined up with them. To the upper left of the moon is the star Regulus. On Saturday Regulus will be just below and to the left of the moon. The comet Ikeya-Zhang can be seen with binoculars just below the head of the serpent in the constellation serpens.

Monday, June 17th. Written by Joseph Slomka.

The Sun sets tonight at 8:36 PM; twilight ends at 10:53 PM. Dawn breaks at 3:00 AM, the earliest of the year; sunrise takes place at 5:16.

As the Sun sets, the First Quarter Moon is already high in the southwest, between Leo's tail and the dim constellation Virgo. Venus is the first planet to be seen since it is both brightest and highest, just West of the Moon. In a telescope it is about three-quarters illuminated. Jupiter appears next, to Venus' lower right. Jupiter is only moderately high and quickly descends into the murky atmosphere above the horizon. Mars is even lower to Jupiter's right, and is so small and dim that one may not see it through the haze.

Comet Ikeya-Zhang is still visible in the constellation Serpens. Tonight it is five degrees East of the globular cluster M 5. Both are binocular objects, and one can see why Messier could confuse a hazy star cluster with a comet.

Roughly between 9:30 and 10:15, the sky is relatively dark, though not totally. The constellation Hercules is high in the East and easily identified by its "keystone" formation. One of the most beautiful celestial objects is a globular cluster, and Hercules has a most spectacular example, M 13. It was discovered by Edmund Halley, of comet fame. It is a ball of about one million stars, 100 light years in diameter, about 25,000 light years distant. Globular clusters are about as old as our own galaxy, 10 billion years. This cluster is seen by the naked eye in very dark skies, and easily in binoculars and small telescopes. It is located on the western edge of the "keystone", one third between stars Eta and Zeta. Binoculars show it to be a hazy patch, but almost any telescope displays thousands of stars. In fact large telescopes are not suitable, since they exhibit only a small piece of this stellar ball. M13 is not the only Globular Cluster in Hercules. M92 lies about nine degrees northeast of its more famous cousin and a half magnitude fainter. On a clear night, take your binoculars and enjoy these beautiful balls of light.

Tuesday, June 18th. Written by Jonathan Cassidy.

First quarter moon was on Monday so moon aficionados have the thrill of seeing the terminator of the moon creep across the face night by night.

The terminator is the line that terminates day and signifies night has arrived along the stark line of the moon, seen tonight just past the half way point. The line is so sharp because the moon has no atmosphere to bend the suns rays and blur the line as we are familiar with twilight on earth.

Shadows of lunar features along the terminator are long because the sun is at the horizon. Thus features on the lunar surface are accentuated by their long shadows.

By watching the terminator creeps over the face of the moon we see a different landscape each night. Binoculars can enhance our viewing and let us pick out large features. Any telescope is even better.

Notice as the moon waxes larger each day that fewer and fewer stars are visible. The increasing light from the moon wipes out our view of dim stars. Thus it is good to study the moon as it does this every month.

Wednesday, June 19th. Written by Ray Bogucki.

Our innermost planet, Mercury, which anchored the western end of the lineup of the five bright planets last month, is now rising as a morning star in the east-northeast about an hour before the Sun. On Friday it will reach its farthest elongation, 23 degrees west of the Sun. By the end of this month it will be joined by Saturn, which will rise next to Mercury on June 30. Binoculars will help in finding these two planets in the early morning twilight a little below and to the left of Aldebaran, the red eye of Taurus, the Bull.

In the evening, Venus, shining at a brilliant magnitude of minus 4, dominates the western sky as it continues its eastward motion through the stars. Tonight and tomorrow night it will lie within one degree north of the bright, open star cluster known as the "Beehive" cluster or M44, in Cancer, the Crab. Again, binoculars will enhance the view.

Tonight, the waxing gibbous Moon lies just north of the bright star, Spica, in Virgo, the Virgin. Last June 10, the Moon cast its shadow upon the Earth. Because the Moon's disk was not quite large enough to cover the Sun's disk completely, only the Moon's antumbral shadow reached the Earth's surface, producing an annular eclipse. Two weeks later, at full Moon next Monday, the Earth will return the favor, casting its shadow on the Moon. In this instance, the Earth's faint penumbral shadow will just brush the Moon's northern limb. The slight darkening of the Moon's edge will probably not be noticed by the casual observer. These two-week apart, sequential solar-lunar eclipses are not uncommon. For example, the next, and darkest penumbral lunar eclipse of this year will be fully visible from the eastern US next November 20. Two weeks later, the new Moon will cast its umbral shadow on the Earth, producing the total solar eclipse of December 4, which will be visible from southern Africa and, three hours later, from southern Australia.

Thursday, June 20th. Written by Alan French.

The planet Venus continues to dominate the western sky just after sunset. Brilliant Venus can be spotted above the west-northwestern horizon just after sunset. It is bright enough to be visible while the western sky is still quite light, and becomes a bright beacon as the sky darkens.

On almost any night an attentive skywatcher would notice a satellite or two passing overhead during the evening hours. Although we are in the Earth's shadow and darkness, satellites high above us are still in sunlight during a period after sunset and before sunrise. During the summer these periods are fairly long. Tonight, for example, satellites are still visible until almost 1 AM.

Satellites appear starlike and move slowly across the sky. Most of them stay about the same brightness across the sky, although they often brighten as they pass overhead. Some satellites, however, vary quite rapidly in brightness because they tumble in space. Tonight the Okean O Rocket will pass over our area, and it is a rapidly tumbling rocket body that flashes two or three times a second. This makes it a very interesting satellite to watch. It was launched on July 17, 1999 from Kazakhstan.

The Okean O Rocket will first appear at 9:19 PM tonight above the south-southeastern horizon. Generally, satellites can be difficult to spot at first appearance, so you might not see it until a minute or two later. It will be highest just after 9:23 PM when it will appear 60 degrees above the east-northeast horizon. If you missed spotting it earlier, look for a moving and rapidly flashing sky height above the east-northeastern horizon at 9:23 PM. This rocket body will vanish above the northern horizon just before 9:28 PM.

Just after 11:00 PM you can see SeaSat1 pass almost directly overhead. SeaSat1, as you might guess, observes the oceans, monitoring ocean currents, wave heights, and surface temperatures. It will appear at 11:11 PM above the north-northeast horizon. Again, it may not be possible to spot it until a minute or so later when it is a bit higher above the horizon. SeaSat1 will pass overhead at 11:16 PM.

While some satellites are visible across the entire sky, satellites often pass into the Earth's shadow and out of sight before they vanish below the horizon. SeaSat1 will pass into the Earth's shadow at 11:19 PM, when still 24 degrees above the south-southwestern horizon. Watch it fade as it moves into the shadow of our planet.

Friday, June 21st to Sunday, June 23rd. Written by George Mileski

Today is the first day of summer, or summer solstice, it is the time when the sun reaches its most northerly point 23 1/2 degrees north of the equator. It is also the longest day of the year. The solstice is the time of the year when the sun stops its northern climb and stands brieftly before turning back toward the equator.

In the east we see the three stars of the summer triangle, the brightest star is Vega in the constellation Lyra. Vega is relatively close at 27 light years. The two best known objects in Lyra are the "ring nebula" and the double-double star "Epsilon Lyrae". The ring nebula can only be seen in a telescope. The double-double star is a quadruple star system made up of two close binaries, for a total of four stars. Binoculars will show only two stars.

The next star in the triangle is Deneb. Its 1600 light-years away, if it were the same distance as Vega you could go outside and read the newspaper, it would be quite bright. This is the brightest star in the constellation Cygnus, "the swan", also the same stars represent "the northern cross", which is an asterism. The last star is Altair in the southeast in the constellation Aquila, "the eagle". Also in the summer triangle is the small constellation Vulpecula "the fox". The stars of Vulpecula are very dim and hard to see. Find the star Albireo, thats the bottom of the cross of the "northern cross" then look slightly to the southeast for Vulpecula. Vulpecula is best known as the location of the "dumbbell nebula"

Northeast of Altair is a small constellation called Delphinas, "the dolphin" and looking at it with of without binoculars it does indeed look like a dolphin. Also north of Altair in the triangle itself is the constellation Sagitta "the arrow". The stars are rather faint but they do look like an arrow facing NE. There is a 7th magnitude globular cluster in it, M71, visible in a telescope. Southwest of the summer triangle is the constellation Hercules. Its kind of dim but you can find the keystone shaped quadrangle halfway between Vega and Gemma in the Northern Crown. There are two globular clusters in Hercules, M13, visible in binoculars and M92. M13 is supposed to be seen naked eye but truthfully I can't see it.

The moon will be above Antares, a giant red star on Saturday the 22nd in the constellation Scorpius. On Monday the moon will be full. In the west there are still three planets to be seen, Venus, Jupiter is to the lower right of Venus and Mars (if you can find it, I can't) is to the right and below Jupiter. Mars is hard to see because its very near the horizon and the skies around here aren't clear.

Monday, June 24th. Written by Joseph Slomka.

The Sun sets at 8:37, with twilight lasting until 10:54 PM. Our Moon, virtually Full, rises shortly and remains up all night. Dawn breaks at 3:48 AM, and ends with sunrise at 5:18.

Venus is the first planet to break through the twilight. It is not as high as it used to be, and observers must start early if they want views unhampered by our atmosphere. Jupiter is next to be seen, but it lies only eleven degrees above the western horizon. Already low in the haze, views of our largest planet will not be very clear. However Jupiter points to a dimmer planet, Mars. Less than four degrees away, they share the same binocular view; just put Jupiter on the left edge and a dim Mars should be seen.

Once the sky has sufficiently darkened, Comet Ikeya-Zhang should still be visible. It is less than two degrees from M-5, the globular star cluster in the constellation Serpens Caput. Since M-5 is a binocular object, the comet should appear as a dimmer ball of light just to the left.

Two themes populate the night sky at this season. During Summer, flying is a major theme. The most prominent flying constellation is Cygnus, the Swan. Cygnus is the cross-shaped constellation overhead. The Eagle, Aquila, appears directly south of Cygnus. The most famous flying constellation is just rising, Pegasus, the Flying Horse. Only one inanimate constellation is included &endash; Sagitta the arrow, which flies between Cygnus and Aquila. The other theme for early summer is that of heroes. Three Greek heroes are featured in tonight's sky. Ophiuchus struggles with the snake Serpens high in southeastern skies; he is also a healer, credited with many cures. Hercules shares the skies as the strongman who triumphed in twelve legendary labors. Finally, Perseus rises after midnight; he tamed Pegasus slew the sea monster Cetus and saved the fair maiden Andromeda.

Tuesday, June 25th. Written by Jonathan Cassidy.

Full moon this week. We can make note of the brightest stars in the sky without distraction of the multitude of dim stars that confuse most people.

Any night the moon is near full only brightest stars shine. From full moon to full moon each month you will notice a change in position of these bright stars. This is because the earth is progressing further around it's orbit of the sun.

There are two stars brilliant each night this time of the year to note relative to the moon. These are Spica and Antares. Both can be found low in the south. They lie along the ecliptic, the path that the moon follows through the month.

Because they lie so close to the path of the moon you will see them very near the moon at different times of the month. This makes them easy to identify. Spica is the western most of the two and is whiter. Antares has a reddish hue. The name Antares is derived from its similarity to the planet Mares, also known as Ares. Antares is the rival of Mars or "anti - Ares".

Wednesday, June 26th. Written by Ray Bogucki.

Around midnight this week, the night sky finds the constellation Hercules high overhead. The best known deep-sky object in Hercules, the globular star cluster designated as M13, is very close to the zenith. A few degrees to the northeast, across the zenith, lies another fine, but often overlooked, globular cluster, M 92. The "M" in these designations refers to Charles Messier, a comet hunter who did his observing in the late eighteenth century.

Messier published a list of over a hundred faint, diffuse objects that might be mistaken for comets by other comet hunters. In his list, which includes open star clusters, globular star clusters, galaxies and various types of nebulas, more than one quarter of the entries are globular clusters. As telescopes increased in size and improved in optical quality, these fuzzy objects were seen to be spherically shaped aggregates of hundreds of thousands of stars, held together by mutual gravitational attraction. More recent spectroscopic studies have determined that the stars in these clusters are very ancient, generally from 10 to 12 billion years old. Their age sets a lower limit on the age of our galaxy.

Globular clusters have also played a pivotal role in our understanding of the overall structure of our spiral galaxy and our location within it. In the early 1900s, the eminent Harvard astronomer, Harlow Shapley, made a careful study of the directions and distances of the approximately hundred known globular clusters. His measurements indicated that these clusters define a huge spherical halo lying largely above and below the plane of the spiral arms of our galaxy. The center of this sphere, and presumably of the galaxy, was found to be a bright spot in the Milky Way in the constellation Sagittarius. This arrangement relegated our Sun from its presumed position near the center of the galaxy, out 30,000 light-years into the far suburbs of one of the spiral arms. Despite their role in our demotion, globular clusters remain favorite targets of amateur astronomers searching for deep-sky objects to observe and ponder.

Thursday, June 27th. Written by Alan French.

The Moon was Full on Monday, so much of tonight will be dominated by the bright waning gibbous Moon. Moonrise tonight is at 11:09 PM and it will set tomorrow morning at 8:50 AM. If you are up just after Sunrise, look for the Moon toward the southwest. A bright Moon can be a very pretty sight against the brightening morning sky.

Last Thursday we talked about some satellites that were passing over, and tonight we will continue in the same vein. An attentive skywatcher would often notice a satellite or two traveling across the sky during the evening hours. Although we are in the Earth's shadow and darkness, satellites high above us are still in sunlight during a period after sunset. The same is true of the hours before sunrise.

While some satellites are visible across the entire sky, satellites often pass into the Earth's shadow and out of sight before they vanish below the horizon. Satellites are more likely to pass into the Earth's shadow later in the evening or earlier in the morning. The path they take across the sky is also important. The two satellites we will talk about tonight will both move into the Earth's shadow before going below the horizon. Watch them fade as they move into the shadow of our planet.

The first satellite is Intercosmos 19. It will appear just after 10:44 PM tonight above the north-northwestern horizon. Look for it rising from the horizon just after this time. It will be highest at 10:48 when it will be almost directly overhead. If you missed it coming up from the horizon, look high overhead at 10:48 for a star moving toward the south-southeast. It will appear as bright as the star that connects the handle to the bowl of the Big Dipper.

Less than one half minute after passing directly overhead Intercosmos 19 will move into the Earth's shadow and fade from view. How long can you still see it?

Our second satellite is Seasat 1, a satellite that is studying the Earth's oceans. It will appear about the same brightness as Intercosmos 19, and will appear above the north-northeastern horizon just after 11:27 PM. It will be highest at 11:32 PM when it will appear almost directly overhead. Look very high above the south-southeastern horizon if you missed seeing it coming up from the horizon. Seasat 1 will move into the Earth's shadow about 90 seconds after passing its highest point. Watch it as it fades.

Both of these satellites have been orbiting the Earth for more than 20 years. Intercosmos 19 was launched on February 27, in 1979, and Seasat 1 was launched on June 27, 1978. Tonight you will be seeing Seasat 1 on its 24th anniversary!

Friday, June 28th to Sunday, June 30th. Written by George Mileski

Mercury is our solar system's innermost planet. Mercury is about a twin of the earth's moon. Both sport heavily cratered surfaces that have remained essentially unaltered for the last three-quarters of the 4.7 billion years since the solar system's birth. The craters are scars from what must have been ferocious bombardments of debris left over from the formation of the planets. Although the earth's crust has undergone many changes since then, the surfaces of Mercury and the moon have not.

It is as difficult to observe details on Mercury as it would be to examine the surface of the moon if it were 300 times farther from earth. Added to that is Mercury's location, near the sun's glare. For these reasons, only a few smudges have ever been recorded from earth. Our knowledge of Mercury's surface stems entirely from photographs taken by the US spacecraft Mariner 10, which flew past Mercury in 1974, the sole human artifact ever to visit that planet, Nasa plans to launch a new probe to Mercury in 2004.

Faint traces of atmospheric gases exist on Mercury but for practical purposes, its airless like the moon. Dramatic changes in temperature occur, temperatures can reach as much as 870 degrees F. during the day, and as low as -300 degrees F. at night.

Areas of unusually high radar reflectivity near the north and south poles, may mean that there is actually a large amount of ice at the poles, in perpetually shadowed crater bottoms. The spacecraft to be sent in 2004 will examine this question. Of the five planets visible to the unaided eye, Mercury is by far the most difficult to observe. The problem for observers is Mercury's tight orbit, which constrains the planet to a small zone on either side of the sun as viewed from earth. For this area the best time to see the planet in the evening sky is within a month or two of the Spring Equinox and in the morning sky within a month or two of the Autumn Equinox.

Because its orbit is between earth's orbit and the sun it shows phases, as our moon shows different phases, however you do need a telescope to see this and of course clear skies. Because its always seen near the east or west horizon, getting clear skies can be a problem. Mercury can be seen before sunrise very low in the NE morning sky, to the lower left of the star Aldebaran.

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