Skywatch March 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 .

 

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

Friday, March 1st to Sunday, March 3rd. Written by George Mileski

When you go outside tonight, face south and bend your head far back and you will see two bright stars, Castor and Pollux about 4 1/2 degrees apart. There, in the constellation of Gemini, the twins, Jupiter just happens to be located southwest of Castor and Pollux also in Gemini. These two first magnitude stars are the brightest in their constellation, where each represents the bright eye of a Gemini twin. These stars have been tied to the idea of twins for so many thousands of years and by so many different cultures, that you might expect them to look alike. But Castor is noticeably fainter than Pollux shining at magnitude 1.6 to Pollux's 1.1.

Castor is also white, while Pollux is golden. We know now that the two are located at different distances from earth, with Castor being 49 light-years away and Pollux 35 light-years. Castor maybe fainter but it is a more interesting star. A small telescope shows it as two separate stars, with a third star nearby. Each of the three is also a double star, so that single point of light we call Castor is really six stars in all.

In Greek mythology, Castor and Pollux were the twin sons of the God Zeus and the mortal Leda. They were the brothers of Helen, whose face "launched a thousand ships" and brought about the Trojan War. Castor was reputed to be the great horseman, and Pollux an expert boxer.

With a little imagination, it is not hard to trace the figure of the twins among the stars of the constellation. With a pair of binoculars and dark skies you should be able to see the open star cluster M35, just west of Jupiter. So what we have in the evening sky are four planets, from east to west Jupiter, Saturn, Mars and Venus. Venus is low in the west at dusk. Venus sets at about 6:40PM.

Monday, March 4th. Written by Susan C. French.

The planet Jupiter is currently within a very large pattern of stars known as the Winter Circle. The circle is very crudely formed, but notable nonetheless. Jupiter is the brightest object in the evening sky now. At 7:30, you can see it high in the south. Letís use Jupiter at that time to find the stars of the Winter Circle.

Use your fist as a measuring tool to find your way around the sky. If you hold your fist at arm's length, it covers about 10 degrees of sky when viewed across the knuckles. For each star, we will picture Jupiter as being at the center of a clock. The numbers that run around a clock can then indicate the direction to each star.

The closest stars of the Winter Circle to Jupiter are Pollux and Castor, the Twin stars of Gemini. They are found 18† from Jupiter in the 10 o'clock position. Pollux is slightly brighter and has a golden color, while Castor is white

Moving clockwise around the Winter Circle, the next star we come to is Capella, in Auriga (oh-RYE-gah), the Charioteer. It is 26 degrees from Jupiter in the 1 o'clock position. Capella is a yellow star.

About the same distance away, but in the 3 o'clock position, we see two bright objects. The brighter one is an interloper, the planet Saturn, which is slowly wandering through the constellation Taurus. The other is the Bull's glaring eye, Aldebaran (al-DEB-uh-ran). Saturn is yellow-white, while Aldebaran is orange.

Now we'll strike out from Jupiter along a direction about halfway between 4 o'clock and 5 o'clock. On our way to the rim of the Winter Circle, we'll bump into the very bright, reddish orange star Betelgeuse (BET-ell-jews) in Orion, the Hunter. Continuing along nearly the same line, we'll reach the blue-white Winter Circle star, Rigel (RYE-gel), also in Orion. Betelgeuse is about 17 degrees from Jupiter while Rigel is about twice as far away.

At about 6 oíclock from Jupiter and 40 degrees away, you will see the brightest star in the night sky, Sirius, in Canis Major, the Big Dog. Sirius is a white star and shows a subtle color contrast with Rigel.

The final star of the Winter Circle lies at 8 o'clock and 26 degrees away. Procyon (PRO-see-on) in Canis Minor, the Little Dog, shines with a yellow-white hue.

Our eyes are not very good at seeing the color in the tiny points of the stars, but by concentrating on bright stars and looking back and forth between them, it becomes apparent that not all of them sparkle like diamonds. Instead, some give off glints of sapphire, ruby, and topaz.

Tuesday, March 5th. Written by Jonathan Cassidy.

Spring is coming and the rising Big Dipper tells us so. During the autumn and winter the Big Dipper was seen to drop in the north west and lay down on the northern horizon.

Now this asterism is rising in the east. The significance of the rotation of the Big Dipper around Polaris, the north star, is analogous to a large spoon dipping in a river for water.

Imagine the Earth is flat with land in the middle and water all around. In the autumn the dipper dropped in the sky toward the horizon. It was empty. In the winter it scooped up water, at the edge of the Earth. As we approach spring it is ready to dump it's nourishing rain on the fields to start the growing year. By summer the Big Dipper will be high over head and will have dumped all it has to nourish the earth. In the Autumn the cycle begins again as it go down toward the horizon for another load for the following spring.

A continual renewing cycle that explains spring rains, drying out of late summer and autumn. A constellation of this type seen all year going around the pole star is called "circumpolar". There are only a few constellations that can be seen to do this. Additional easy to find constellations include Cassiopeia, Cepheus and Ursa Minor the little dipper.

Wednesday, March 6th. Written by Michael Molitor.

The magnitude of a star is its apparent brightness as we observe it here on earth. The dimmer the star, the larger the magnitude number. A star of 1st magnitude is brighter than one of 2nd magnitude, and dimmer than one of zero magnitude. For very bright objects, magnitude can even be a negative number.

The star in the upper left shoulder of the constellation Orion is Rigel. Rigel is the brightest star in Orion and it shines very close to magnitude zero. Orion’s left leg or knee is marked by the star Saiph at magnitude 2. The brilliant star Sirius, due south this evening, shines at magnitude &endash;1.4 (minus 1.4). Distance is one factor that determines how bright a star appears to us. Saiph is over 800 light-years from earth, while Rigel is 180 light years away, and Sirius is nearby at 8.7 light years.

Our Sun is very close to the Earth and has a magnitude of &endash;26.7. It sets at 5:51pm today and rises at 6:22am tomorrow morning.

Three planets are readily visible around 8pm this evening. Mars is low in the west at magnitude 1.3, Saturn is midway up in the southwest at magnitude 0, and Jupiter is a little south and west of overhead at magnitude &endash;2.4. Jupiter is the brightest object in the sky this evening.

The Moon, at magnitude &endash;9.4, is one day past last quarter and rises after midnight at 2:41am. Look for the Moon tomorrow morning on your way to work or school. Follow it throughout the morning if you can, noting that it will set in the west, just before noon tomorrow.

Thursday, March 7th. Written by Peter Jennes.

Moonrise is close to 4 AM and without the interference of moonlight or light pollution, observers should be able to see the winter Milky Way. Compared to the summer Milky Way, the winter Milky Way is much dimmer and harder to trace across the sky than its summer counter-part. The difference between the summer and winter Milky Way is a product of our view into space. During the summer, our nighttime view peers down the arm of our galaxy that spirals in towards the Milky Way’s star rich core. Because the richest star fields appear closest to Sagittarius, this branch of the galaxy is called the Sagittarius Arm of the Milky Way.

As the seasons change to winter and the sky rotates overhead, our view of the winter Milky Way is directed 180 degrees away from where it was in the summer. Where summer nights look into the heart of our galaxy, winter nights display the outer fringes of our galaxy. Like all outer fringes, the outskirts of our galaxy have a much lower population density than the urban center of the galaxy. With less stars to look at, the winter Milky Way fades from its summer glory. Despite the lack of dense star clouds, the galactic arm of the winter Milky Way can be traced up through Perseus in the north, into Auriga, then down past Orion and into Canis Major in the south. From its northern-most extremity, the winter Milky Way receives its name the Perseus Arm.

Tonight, the winter Milky Way and the constellation Perseus will be high in the northwest at 7:30. An easy way to find Perseus is to look for the circle of Auriga and the bright star Capella. At the same time, look for the twin stars Castor and Pollux in Gemini. If you draw a lines through Castor and Pollux and continue past Capella, the next bright stars you come to belong to Perseus. Using binoculars, scan a region around these stars. You will soon notice that this area contains many more stars than regions further east or west. This path of concentrated stars marks the trail of the Perseus Arm of our galaxy. As you follow this trail, keep in mind that just beyond those stars lies the vast loneliness of intergalactic space.

Friday, March 8th to Sunday, March 10th. Written by George Mileski

The sun is our local star. It provides the light, heat and energy for life. The sun is about 865,000 miles across and is about 93,000,000 miles from earth. Its 109 times the size of earth. The sun is so big you could fit 1,300,000 earths inside of it. The sun's total energy output is enormous. The amount of the sun's energy that falls per second on earth's outer atmosphere, called the solar constant is about 126 watts in a square foot. This amount of energy provides about as much heat and light in a week as is available from all of our known reserves of oil, coal and natural gas.

The theory is that our sun and its planets formed together from a rotating cloud of interstellar gas and dust called the solar nebula about 4.6 billion years ago. The sun has more then 99 precent of the mass of the solar system and provides the gravitational force that keeps the planets circling around it. Its surface gravity is practically 28 times earths. The sun is a hot ball of gas, shining under its own power with energy from nuclear fusion, turning hydrogen into helium every second near the center of the sun. The surface of the sun is called the photosphere with a temperature of about 10,000 degrees Fahrenheit. Above the photosphere is the chromosphere, its only about 600 miles thick with a temperature of about 18,000 degrees F. The only time we can see the chromosphere is during a total eclipse of the sun, when it glows red due to its hydrogen gas. The next region is the corona above the chromosphere. It is a rarified hot gas that extends millions of miles into space with a temperature of almost 2,000,000 degrees F. It is one of the mysteries of the sun as to why from the surface on out into space the temperature gets hotter.

The sun and the earth rotate counter-clockwise. All of earth makes a complete turn in a day. The whole sun does not turn around at the same rate. The period of rotation for one complete turn is faster at the sun's equator, about 25 days and slowest at the poles, about 35 days.

It is estimated the sun has enough fuel for about another 5 billion years, so with that said, you can rest easy tonight.

There is a comet look at, comet Ikeya-Zhang. To find it, look for Mars in the west. Using binoculars, it should be visible below Mars. Try this about one hour after sunset. The comet is very low in the west

Monday, March 11th. Written by Joseph Slomka.

The Sun sets at 5:57, with night falling at 7:31. Dawn breaks at 4:39 AM, with sunrise taking place at 6:13.

As the sky darkens, a parade of bright planets grace the Western sky. Venus is brightest, in the southwest. It is low, eleven and a half degrees high; trees, hills or buildings could hide this planet. However, Jupiter is quite bright high in the southwest, Saturn a bit lower, Mars lower still. As twilight deepens, Jupiter is found in Gemini, while Saturn occupies the space above the Bull's Eye in Taurus. Comet Ikeya-Zhang lies between Mars and Venus. Can you spot it in binoculars or by eye alone? Predictions say it should be visible, but no one in the Capital District has seen it yet. It is certain that the odds of seeing it are improving daily. In about a month the comet will be easily visible in pre-dawn skies.

Between the constellations Gemini and Leo lies an almost empty patch of sky. Cancer, the Crab, occupies this area. This constellation dates to the ancient Greeks. On dark, moonless, nights like tonight, the constellation has the appearance of five stars in an inverted "Y". Cancer is part of the zodiac, the path of the Sun, Moon, and planets through the sky. Cancer is important because, 2000 years ago, it marked the highest part of the Sun's journey, the summer solstice. In our times, this point lies on the Gemini/Taurus border. This shift is due to precession, a slow, but noticeable, wobble in the Earth's rotation in a 26,000 year cycle. In 24,000 years the cycle will repeat, with Cancer again center of attention. Cancer is famous for the galactic cluster M44, known as the "Praesepe" or "Beehive." Although visible to the naked eye on moonless nights, this group of stars requires binoculars to fully appreciate its beauty. Indeed, the stars do resemble a swarm; about 200 stars are members of this group. The Beehive" is about 40 light years in diameter and 525 light years distant.

Tuesday, March 12th. Written by Jonathan Cassidy.

New Moon is coming up on Thursday March 14th. This is the darkest week of the month. A good time to go out and find dim objects in the sky.

Find a star cluster tonight with your naked eyes. Go out after twilight, when the sky is as dark as it will get. Look to the south, low to the horizon for the brightest star in the sky: Sirius. Go to the north east or upper left and find the next brightest star Procyon. Travel a line from Sirius to Procyon and take this line the same distance beyond Procyon. You are now looking at a relatively featureless part of the sky.

At least on first inspection there seems to be not much in this area. If you have traveled correctly you are now in the middle of a large triangle of bright stars with Procyon to the lower right, Regulus to the left and Pollux to the upper right, but nothing much where you are.

Look close, you might have to get away from local lights that pollute the view. You will find a dim inverted "Y" of stars. Very near the center of the "Y" you will find a fuzzy patch. This patch can be seen from light polluted cities if you know where to look and can get into a shadow.

This is the "Beehive cluster" known as M-44. It is a favorite object for binocular astronomy.

Wednesday, March 13th. Written by Ray Bogucki.

The alignment of celestial bodies is always interesting to observe. The Moon and all of the planets travel in paths that are close to the ecliptic, the path of the Sun through the stars. Thus, in its monthly voyage across the sky, the Moon will pass close to each of the planets. Occasionally it will pass directly between the Earth and a planet, blocking our view in an event called an occultation. For the past several months the alignments have been just right for the Moon to occult Saturn and Jupiter on each pass, as viewed from different places on the Earth's surface.

Last month the occultation of Saturn was visible from our area but for the next two cycles, we will see the Moon come very close but not quite touch Saturn. On May 14, the current series of occultations of Saturn will end in spectacular fashion when the Moon occults Saturn, Mars and Venus all in the same day.

Another fascinating alignment occurs when two of Jupiter's bright moons pass together between Jupiter and the Sun, casting their tiny dark shadows on the surface of the planet in an event known as a double shadow transit. Tonight, about 13 minutes past midnight, you can watch the shadow of Io, the innermost Galilean moon, join the already present shadow of Europa, the third moon. This pairing of shadows, observable with a modest-sized telescope, will occur on three consecutive Thursdays, about 2 hours later each time, until the two moons fall out of register and the series ends. One can imagine the excitement Galileo would have felt if the resolution in his primitive telescope had allowed him to witness these shadow transits. They would have provided him with the conclusive proof he needed to convince a doubting world that these little points of light he had discovered were truly moons orbiting Jupiter.

Thursday, March 14th. Written by Peter Jennes.

Around 9 PM, two first magnitude stars separated by 5 degrees will be located almost directly on the zenith. These stars are the Twins, Castor and Pollux in Gemini. Pollux is a K-type orange star 34 light-years from Earth while Castor is a multiple star 52 light-years away. Castor’s main components are both A-type, white stars with spectroscopic binary companions. About half-way between the eastern horizon and the Twins lies another bright star, Regulus the heart of Leo the Lion. Regulus sits near an imaginary line called the ecliptic. The ecliptic marks the path of wandering solar system objects like the moon as they travel across the sky. As it follows the ecliptic, the moon is often found close to Regulus and sometimes even covers the star over.

Because of its proximity to the ecliptic, many ancient cultures saw Regulus as more than the Heart of the Lion. For those ancient cultures, Regulus also marked the Heart of the Heavens and joined Aldebaran, Antares, and Fomalhaut as the Guardians of Heaven. Regulus is about 85 light years away and nearly 160 times brighter than the Sun. Regulus is so bright because it has a very high surface temperature and in the world of physics, hotter equals brighter. The hottest stars are blue, followed by white, then yellow, orange, and finally red. Since Regulus is blue-white, we know its surface is much hotter than that of our own yellow Sun. In fact, measurements indicate that Regulus has a surface temperature of about 13,000 degrees which compares to the cool 5,000 degrees radiating off our Sun's surface.

Another factor that helps make Regulus bright is its size. Astronomers believe Regulus is about five times larger in diameter than the Sun. This means that Regulus has over six times more surface area to radiate light off of than does our Sun. If you have ever compared a flashlight to a car headlight, you know the difference size makes when it comes to luminosity. Since Regulus is more massive and much hotter than the Sun, Regulus consumes nuclear fuel at a faster rate than the Sun. Because of that, Regulus will use up its nuclear fuel more quickly, and live a shorter life than our Sun.

Friday, March 15th to Sunday, March 17th. Written by George Mileski

The Constellation Leo the Lion is quite high from the horizon after it gets dark. It is a large constellation, with three bright stars. The brightest one is Regulus. It is easy to find when the big dipper is high up. Use the two stars of the dippers bowl next to the handle and draw a straight line down. it will first hit the star in the Lion's shoulder called Algieba and then Regulus. Regulus is a bluish-white star about 80 light-years away and over 100 times as luminous as the sun. At the end of the Lion's tail is the second brightest star called Denebola. The third bright star in Leo is Algieba "the lions mane". It is a spectacular double star. In a telescope they appear yellow and green.   

When you look at Leo the Lion, the front part or head besides looking like a lion, also looks like a sickle or a backward question mark. Above the head of Leo, is Leo Minor or "the small lion" Its a small dim constellation very hard to see, you need a dark location and a star map to find it. 

Now we move south to the largest constellation in the sky, Hydra "the sea serpent" The head of the serpent is about halfway between Regulus and Procyon in Canis Minor. It consists of five stars and is not that difficult to see. In Leo the Lion if you extend a line from Algieba to Regulus and beyond you will run into the brightest star in Hydra called Alphard. The Constellation Hydra kind of meanders all over the south eastern sky, it is so big. Its stars are very dim except for Alphard and because its low to the horizon, it makes it harder to see. 

In Greek mythology, Hydra is the nine-headed serpent of the Lerna Marshes, slain by Hercules in his second labor. As one head was cut off two others grew in its place. But Hercules faithful Iolaus solved the problem by searing the stump as each head was severed. One head was immortal and was placed by her under a great stone. Thats enough of Greek mythology for tonight. 

On Friday the 15th at dusk, look in the west for a thin crecsent moon with Venus at its lower right. On Saturday the moon will be approaching Mars. On Sunday Mars will be on the upper right of the moon. Also the in west is the comet Ikeya Zhang. Its about 12 degrees below and a little to the right of Mars. On Saturday the comet will be to the right of the crescent moon. Check for the comet about 45 minutes or so after sunset. The comet's position changes a little every night.    

Monday, March 18th. Written by Joseph Slomka.

The Sun sets tonight at 6:05 with night falling at 7:40. The Moon's thin crescent is already up and sets at 10:42 PM; the Moon will not be a serious problem for observers. Dawn breaks at 4:26 AM tomorrow, and ends with sunrise at 6:01.

As the Sky darkens an interesting planetary alignment helps find a truly rare object. Overhead, Jupiter blazes. It is easily the brightest object in the darkening sky. Saturn is the next brightest object to Mars' west, in the constellation Taurus. The Moon is next; its thin crescent is easily visible. Mars is below the Moon. Venus is at the end of this line; however trees, buildings, or hills may hide its low position.

Comet Ikeya-Zhang is currently visible to binocular viewers. The comet is now just to the West (right) of Mars. In typical binoculars, it is about three fields away from Mars. From my backyard, it is visible against the Schenectady skyglow. It appears almost star like, with a short tail pointing upward (away from the Sun). This comet is becoming very interesting. It will be easier to observe next month, after it swings around the Sun and appears in dawn skies. With almost three hundred observations, specialists who calculate comet orbits determined that this is a return visit! The comet once graced the night in 1661. If that were true, the original Dutch settlers of Albany would have seen this same comet.

Another interesting sight is visible in pre-dawn skies. The constellation Scorpius rises after midnight and is best visible before sunrise. However, Scorpius looks different somehow. Over the last few months, the star Beta in Scorpius, the top star in the head, has suddenly brightened. This has happened before, but the current event was unexpected. Some stars vary on a schedule so precise, you could set your watch by it; others vary over a period of years. This star belongs to a third class that had no detectable period. The causes of such variations are little known. Scorpius is best viewed at about 4 AM and found in the southeast.

Tuesday, March 19th. Written by Jonathan Cassidy.

Our Moon and Saturn

Tonight the Moon approaches two bright lights in the sky. One is a star and the other is a planet. The star is Aldebran and the planet is Saturn.

If you remember last month the Moon occulted the view of Saturn. This month it only comes near the planet as we see it. Actually the Moon never gets far from Earth and never goes near Saturn, but our line of sight brings them close together as we see them in the sky.

The star shines by light it emits from its nuclear reactions. The Moon and Saturn shine by means of reflected light. The light each reflects comes from our own Sun. With Saturn the light has to go out from the Sun past Earth before it hits the planet surface. Then reflected light returns to us. In this way it takes light from the Sun additional time to get to Saturn and return to us.

If the light from the Sun went out would see it stop shining about eight minutes after because light travels at 186,000 miles per second and has over 90,000,000 miles to go. In the same way the full Moon would still shine about two seconds longer. Saturn would shine for several hours more till the last of the Sun's light arrived at Saturn and returned reflected light to us.

Wednesday, March 20th. Written by Ray Bogucki.

Today, at 2:16 p.m., the Sun, travelling along the path of the ecliptic, crossed the celestial equator moving from south to north. The point of crossing, called the vernal equinox, is located in the constellation Pisces, the Fishes, and has the celestial coordinates of zero hours right ascension and zero degrees declination. The crossing marks the beginning of spring in the northern hemisphere and autumn in the southern hemisphere. At all inhabited points on the Earth today the Sun rose due east about 6 a.m., and set due west just 12 hours later. At the precise north and south poles, the Sun, halfway up on the horizon, slowly marks the rotation of the Earth by moving around the 360 degrees of the horizon in 24 hours. The North pole now begins 6 months of uninterrupted sunlight, while the South pole will not see the Sun again until our autumnal equinox on Sept. 22.

In the night sky, the third largest asteroid, Vesta, shining at 8th magnitude, appeared to pass very close to Saturn last night, and when the Moon occulted Saturn, as seen in Asia at 5 this morning, it covered Vesta at the same time in a rare double occultation. This unusual solar system event placed the Earth, the Moon, Vesta and Saturn all in a straight line. Vesta is about 334 miles in diameter and is currently about 250 million miles away while Saturn stands at 867 million miles. Tonight Vesta sits about one Moon-width due east of Saturn. Its motion against the background stars should be apparent in an hour or two of observing.

Tomorrow night, in the early evening, the Moon will pass through the large open star cluster, M35, in Gemini. A small telescope will allow the rare opportunity to watch the advancing, dark limb of the Moon snuff out many 8th magnitude stars in a short period of time.

Thursday, March 21st. Written by Peter Jennes.

This evening, the first quarter Moon sits about 7 degrees below Jupiter. A line drawn from Jupiter through the Moon cuts across Saturn, Mars, and Venus on its way to the horizon. Look early for Venus because the planet is just entering the evening sky and sets about one hour after sunset.

Although the weather does not seem to care, today is the first full day of Spring. If nothing else, yesterday’s snow makes it clear that the passage into Spring is an astronomical event and has very little to do with northern weather. The passage into Spring occurred just after 2 PM yesterday when the Sun passed directly over the Earth’s equator. For a few days, as the Sun crosses from south to north of the equator, the hours of daylight are nearly equal to the hours of night. This equality of day and night forms the Latin root for the Vernal Equinox; the astronomical name for Spring.

To explain this a little more, imagine a disk projected straight out into space from the Earth’s equator. Yesterday afternoon, the Sun passed through this imaginary disk. The point of intersection created when the Sun passes through the disk is the Vernal Equinox. The Sun’s position relative to this disk changes throughout the year because each day, the Earth and our imaginary disk move ahead in their orbit.

While the Earth’s position relative to the Sun changes, the position of the Earth’s axis relative to the stars remains relatively unchanged in position to the disk. In other words, the Earth’s axis of rotation points at the North Star regardless of what time of day or which day of the year it is. Therefore, when the Earth is on one side of its orbit, our axis points towards the Sun and the North Star. However, when the Earth is on the other side of its orbit, the Earth’s axis still points at the North Star but away from the Sun. Since the orientation of the equator and its projection into space are fixed in relation to the Earth’s axis, the Sun appears to move north and south of the equator as the Earth moves around the Sun. That apparent motion of the Sun drives the seasonal progression here on the surface of our Earth.

Friday, March 22nd to Sunday, March 24th. Written by George Mileski

On Friday the 22nd, the moon will be in Gemini. Jupiter the largest planet in our solar system will be west of the moon, shining very brightly at magnitude -2.3. Continuing west will be Saturn in the constellation Taurus, followed by ruddy Mars in Aries and lastly brilliant Venus, very low in the west. Venus sets a little over an hour after sunset. So you have to look quickly after sunset to see it. Also in the west is the comet Akeya Zhang, use binoculars to find it. It is located to the right of Mars, several binoculars fields away. 

This comet was discovered independently on February 1st by a Japanese and a Chinese amateur astronomer. It is believed that this comet is a returning object last seen in the year 1661. The comet reached perihelion with the sun on March the 18th. It should be the brightest by the beginning of April and should be a naked eye object by this time. By this time in April, the comet will have moved into Andromeda, not to far from the famous galaxy M31.  

I was looking at this comet last Saturday night with binoculars and my telescope and it is indeed a pretty sight. I'm not sure by degrees how long the tail was but it was very inpressive and very easy to see. At this time we have a gibbous moon, which simply means we're going to have to contend with a lot of light. And I'm not sure how easy its going to be to see the comet under these conditions.  

On Sunday the moon will be between Gemini and Leo the Lion. The brightest star in Leo will be east of the moon. That star is Regulus. Of all the brightest stars in the sky, the one that sits almost directly on the ecliptic is Regulus. The ecliptic, of course is the path the sun follows across the sky. The planets also follow the ecliptic, although they can be above or below it, at times.     

Monday, March 25th. Written by Joseph Slomka.

The Sun sets at 6:13 with night falling at 7:49 PM. The Moon is already up and will stay up for most of the night. Dawn breaks at 4:13 tomorrow morning, and ends with sunrise at 5:48 AM.

Even in the bright moonlight, the evening planets should be easily visible. Jupiter is virtually overhead and is the next brightest object, Saturn appears lower and west of Jupiter, Mars is lower still, with Venus hovering just over the horizon. Jupiter and Saturn are nice binocular objects.

After spotting Mars, shift your binoculars about three or four fields to the West. You may be able to spot comet Ikeya-Zhang through the moonlight. This comet is better in dark skies, and will be a nice early morning sight in a week or two. But Ikeya-Zhang is not the only comet in our skies. Amateurs also recently discovered two more comets. Comet Snyder-Murakami and Comet Utsunomiya are currently very dim and difficult to observe. However, they emphasize that amateurs still can contribute to science.

If the skies were darker, you would see the tail of Comet Ikeya brush past the galaxy known as M-33. This evening's conjunction of Comet and Triangulum Galaxy recreates an important event in astronomical history. Comet hunting is responsible for several significant discoveries. The Eighteenth Century French astronomer Charles Messier frequently observed an object that he thought was a comet, but later turned out not to be. To avoid future confusion, he listed one hundred and ten such objects. His instruments were not sensitive enough to resolve these objects. Later, with improved telescopes, astronomers realized that these objects were distant galaxies and star clusters. Today, the Messier List provides the basic agenda for beginning astronomers to master.

Comets are interesting objects. They represent remnants from the distant reaches of the universe. They come from outside the Solar System under the Sun's gravity. They are basically ices and dust lumped together. As the comet nears the sun the ice boils off and gives off the distinctive tail. Some comets, like Ikeya-Zhang, repeatedly visit the solar system, others are one-time visitors.

Tuesday, March 26th. Written by Jonathan Cassidy.

Near full Moon tonight. Full Moon is actually on the night of Thursday the 28th. With the Moon reflecting so much light from the Sun much of the sky is washed making it impossible to see dim objects.

Tonight's Moon is located in the constellation Leo the lion. When it is full on Thursday night it will be in Virgo.

Take note of the few bright stars you can see. These stars are the signposts for observers. Many amateur astronomers can name the brightest stars.

A bright star you might notice tonight just to the right of the Moon is Regulus. This is the most prominent star in the constellation Leo. The next bright star to the east is Arcturus in the constellation Bootes. Between Regulus and Arcturus is a region called the Virgo Cluster of Galaxies.

Though you can not see these without the aid of a telescope you might imagine hundreds of galaxies clumped together so close that many can be seen in one eye piece field of view. To make it possible to find this area in dark skies we need to know to start first at the bright star Leo and travel to the east toward Arcturus noting ever dimmer stars along the way as our signposts. This week anyone can see the brightest stars and know their names.

Wednesday, March 27th. Written by Ray Bogucki.

At the time of the spring equinox, the Sun moves northward in our noon sky at a faster pace than any other time of the year. The effects of this motion are readily apparent. Each morning the Sun rises 2 minutes earlier from a spot a little farther north on the eastern horizon than sunrise of the previous day. In the West, the Sun sets about a minute later and a bit farther north each evening. At noon the Sun climbs three-quarters of one solar diameter higher each day. In just the one week since last Wednesday's equinox, we have added 21 minutes to the sunlit hours and have seen the Sun climb almost 3 degrees higher in the southern sky.

This rapid northward motion of the Sun is caused by the 23 degree tilt of the Earth's rotational axis to the plane of the ecliptic. For residents of the Albany area, and anyone else at 43 degrees north latitude, the celestial equator always meets the western horizon at an angle of 47 degrees. The added 23-degree tilt of the ecliptic to the north brings the angle between the ecliptic and the horizon to a steep 70 degrees. One can easily visualize this angle by stepping outside about an hour after sunset and noting the line formed by the planets Jupiter, Saturn and Mars, all of which line on or close to the ecliptic. With a clear view of the western horizon, you might even glimpse Venus, very low, adding to the line of planets as it emerges from behind the Sun to climb into the western sky as the dominant evening star.

The steep angle of the ecliptic presents us with our best opportunity for this year to witness the elusive, evening Zodiacal light. From a very dark sky location, as the regular evening twilight fades into darkness, a ghostly, white pyramid of faint light will persist, rising from the western horizon toward Jupiter, and centered upon the line of the planets. This light is the faint reflection of sunlight from the countless tiny dust particles that fill the interplanetary space in the plane of the inner solar system.

Thursday, March 28th. Written by Peter Jennes.

This evening, the first quarter Moon sits about 7 degrees below Jupiter. A line drawn from Jupiter through the Moon cuts across Saturn, Mars, and Venus on its way to the horizon. Look early for Venus because the planet is just entering the evening sky and sets about one hour after sunset.

Although the weather does not seem to care, today is the first full day of Spring. If nothing else, yesterday’s snow makes it clear that the passage into Spring is an astronomical event and has very little to do with northern weather. The passage into Spring occurred just after 2 PM yesterday when the Sun passed directly over the Earth’s equator. For a few days, as the Sun crosses from south to north of the equator, the hours of daylight are nearly equal to the hours of night. This equality of day and night forms the Latin root for the Vernal Equinox; the astronomical name for Spring.

To explain this a little more, imagine a disk projected straight out into space from the Earth’s equator. Yesterday afternoon, the Sun passed through this imaginary disk. The point of intersection created when the Sun passes through the disk is the Vernal Equinox. The Sun’s position relative to this disk changes throughout the year because each day, the Earth and our imaginary disk move ahead in their orbit.

While the Earth’s position relative to the Sun changes, the position of the Earth’s axis relative to the stars remains relatively unchanged in position to the disk. In other words, the Earth’s axis of rotation points at the North Star regardless of what time of day or which day of the year it is. Therefore, when the Earth is on one side of its orbit, our axis points towards the Sun and the North Star. However, when the Earth is on the other side of its orbit, the Earth’s axis still points at the North Star but away from the Sun. Since the orientation of the equator and its projection into space are fixed in relation to the Earth’s axis, the Sun appears to move north and south of the equator as the Earth moves around the Sun. That apparent motion of the Sun drives the seasonal progression here on the surface of our Earth

Friday, March 29th to Sunday, March 31st. Written by George Mileski

On Friday the 22nd, the moon will be in Gemini. Jupiter the largest planet in our solar system will be west of the moon, shining very brightly at magnitude -2.3. Continuing west will be Saturn in the constellation Taurus, followed by ruddy Mars in Aries and lastly brilliant Venus, very low in the west. Venus sets a little over an hour after sunset. So you have to look quickly after sunset to see it. Also in the west is the comet Akeya Zhang, use binoculars to find it. It is located to the right of Mars, several binoculars fields away. 

This comet was discovered independently on February 1st by a Japanese and a Chinese amateur astronomer. It is believed that this comet is a returning object last seen in the year 1661. The comet reached perihelion with the sun on March the 18th. It should be the brightest by the beginning of April and should be a naked eye object by this time. By this time in April, the comet will have moved into Andromeda, not to far from the famous galaxy M31.  

I was looking at this comet last Saturday night with binoculars and my telescope and it is indeed a pretty sight. I'm not sure by degrees how long the tail was but it was very inpressive and very easy to see. At this time we have a gibbous moon, which simply means we're going to have to contend with a lot of light. And I'm not sure how easy its going to be to see the comet under these conditions.  

On Sunday the moon will be between Gemini and Leo the Lion. The brightest star in Leo will be east of the moon. That star is Regulus. Of all the brightest stars in the sky, the one that sits almost directly on the ecliptic is Regulus. The ecliptic, of course is the path the sun follows across the sky. The planets also follow the ecliptic, although they can be above or below it, at times.     

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Dudley Observatory
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