Posted on by Fraser Cain

What’s Up This Week – Dec 6 – Dec 12, 2004

Image credit: David Malin
Monday, December 6 – If you’re up before dawn this morning, be sure to take a moment to step outside and have a look at the Moon and Jupiter. This morning the Moon will appear above and to the right of the “Mighty Jove”, but tomorrow morning they are going to be a whole lot closer! And speaking of closer, somewhere out there in the asteroid belt, it’s going to be a busy Monday because Asteroid 2002 YP2, Asteroid 12382 Niagara Falls and Asteroid 12397 Peterbrown all make their nearest approach to the Earth today.

For Northern Hemisphere observers, today Comet C/2004 Q1 (Tucker) is at perihelion, or the nearest point in its orbit of the Sun today. With an estimated magnitude of 10, Comet Tucker should be visible to both large binoculars and small telescopes sliding through Andromeda just a bit southwest of M31. As with all comets, activity increases as they near the Sun, so be on the lookout for coma or above average brightenings.

Tonight’s unusual treat is for the Southern Hemisphere viewer when the Phoenicid meteor shower reaches its peak. With an estimated fall rate of about 5 per hour, this particular shower might not seem very exciting, but it has an unusual place in history. In 1956 over 100 meteors per hour were recorded, marking the point of this shower’s discovery. The stream is believed to be the offspring of the long lost periodic comet Blanpain observed in 1819. Although the exact time of peak activity is currently unpredictable, past observations show this meteor shower begins right after sunset and radiates from constellation of Phoenix. It is unusual because it leaves very few visible trails but is well-known for its bright flashes and exploding fireballs! Lucky birds…

Tuesday, December 7 – Wake up North America! This morning is a grand occulation of Jupiter by the Moon. Encompassing Canada and the biggest majority of the United States (for you who are still warm? sorry… you’ll only get a grazing event.) the Moon will silently slide over Jupiter at the unholy hour of just before 4:00 a.m. Since timing is especially critical in these type of events, you must visit the IOTA predictions for precise times in your area. (relax Florida keys and south Texas, there’s times in there for your graze as well.) This provides a wonderful opportunity for photographs as well as just a spectacular event to witness. It is especially fitting since the Galileo spacecraft went into orbit around Jupiter on this day in 1995. So hug your loved one, hug your scope, hug your dog, or just watch Venus and Mars still hugging the horizon and enjoy!

While waiting on Jupiter to re-appear, those of you with large aperture telescopes might like to take the opportunity to view Comet Tsuchinshan at perihelion this morning. Although this comet has been holding a recent magnitude of 13, it may reach an estimated magnitude of 11 by this time. It has moved quietly across the southern border of Leo for the last few weeks and should be quite near Beta Leonis and the Coma Berenices border at this time.

On a side note, Apollo 17 was launched on this date in 1972, Gerard Kuiper belted his way into fame by being born on this day in 1905 and this is also the earliest sunset of the year. Astronomers? Let’s celebrate!

Wednesday, December 8 – If you are out this morning before dawn, take a moment to find bright Venus down on the horizon and work your way up the sky as Mars, the crescent Moon, Spica, and Jupiter form nearly a straight line across the winter skies.

Asteroid 4701 Milani, Asteroid 2004 RZ164, Asteroid 3353 Jarvis and Asteroid 2062 Aten all make their closest approach to the Earth today and Comet C/2004 S1(Van Ness) is at perihelion. At a rough magnitude of 16, this newly discovered comet will be in the range of professional observing. Ephemerides are provided by following the link (and I’ll see you at the observatory).

For binoculars and small telescopes, tonight would be a great opportunity to hunt down a southern Messier object in Capricornus. At magnitude 8, the M30 can be found just a bit over 6 degrees south of Gamma Capricorni. To smaller aperture telescopes and large binoculars, this 40,000 light year distant globular cluster will appear small and faint, but larger telescopes will see a dense, bright core and splendid resolution. As an added bonus, 41 Capricorni (in the same field of view) is a double star!

Thursday, December 9 – Looking for an unusual photo opportunity? Then check out Mars this morning as it appears almost between the very slender crescent Moon and Venus. Coupled with “earth shine” this trio will be very low on the horizon!

While we’re enjoying early evening dark skies, the window opens for binoculars and small telescopes to locate one of the largest and most spectacular of the southern globular clusters – the M2! By heading north/northeast of Beta Aquarii (remember this star – we’ll use it again), the 6th magnitude M2 (NGC7089) will show to small aperture scopes as well as binoculars and turn into stunning resolution in the large telescope. Cataloged by Messier 1760, this 150 light year wide “ball of stars” might seem less impressive than the M13, but at 50,000 light years in distance it’s significantly further away!

Southern Hemisphere viewers, you’re in luck again! Tonight will be the maximum of the Puppid-Velid meteor shower. With an average fall rate of about 10 per hour, this particular meteor showing could also be visible to those far south enough to see the constellation of Puppis. Very little is known about this meteor shower except for the streams and radiants are very tightly bound together. Since studies of the Puppid-Velids are just beginning, why not take the opportunity to watch? Viewing will be all night long and although most of the meteors are faint, it is known to produce an occasional fireball.

Friday, December 10 – Do you think you can catch Luna one last time? Then try again this morning as the Moon will make its final dawn appearance very close to the horizon. Just above it will be Venus, and higher to the left will be tiny Mars. Missing Mercury is now at perihelion – its closest approach to the Sun – but it is also at inferior conjunction, making it invisible to us because it is hiding between the Earth our “nearest star”.

Tonight will be the peak of the Monocerotid meteor shower. Here again we have an example of an obscure and unstudied shower because no one is sure of exactly where the precise radiant is located. By keeping watch loosely on the constellations of Gemini and Monoceros, you may see a few of these faint and fast meteors at a rate of 3-12 per hour. Who knows? Perhaps one of these strange meteors may have been responsible for the observed fall in 1984 that hit a Claxton mailbox!

While out viewing tonight, take advantage of the moonless early evening to try hunting down a very large and elusive galaxy that can be spotted with binoculars and even unaided from a very dark observing site. The M33, or “Triangulum Galaxy” is very misty, vague and also a totally wonderful galaxy for study. Just west of Alpha Triangulum, this galaxy is about the size of the full Moon, but it is so diffuse it’s sometimes hard to locate. Cataloged by Charles Messier in August 1764, the M33 is often known as the “Pinwheel”, because of its distinguishable arm structure. As a part of our local galaxy group, the M33 (NGC598) is quite prized by amateurs for its ability to resolve. It has a distinct concentration toward the nucleus area plus a northern and southern “arm” that are within a small telescope’s capabilities. Telescopes ranging between 12.5″ to 16″ and larger will find a wealth of NGC and IC objects hiding within this fantastic galaxy, allowing us to study star clusters and nebula almost 750,000 light years away. It’s out there tonight!

Saturday, December 11 – For those of you who like to get up early to capture space oddities, this morning Mars will occult TYC 6174-00681-1 (10.2 magnitude star).

On this date in 1863, Annie Jump Cannon was born. She was a United States astronomer who created the modern system for classifying stars by their spectra. Why not celebrate this achievement by coming along with me and viewing some very specific stars that have unusual visual spectral qualities! Let’s grab a star chart, brush up on our Greek letters and start first with Mu Cephei. Nicknamed the “Garnet Star”, this is perhaps one of the most red stars visible to the unaided eye. At around 1200 light years away, this spectral type M2 star will show a delightful blue/purple “flash”. If you still don’t perceive color, try comparing Mu to its bright neighbor Alpha, a spectral type A7, or “white” star. Perhaps you’d like something a bit more off the beaten path? Then head for S Cephei about halfway between Kappa and Gamma toward the pole. Its intense shade of red makes this magnitude 10 star an incredibly worthwhile hunt.

To see an example of a B spectrum star, look no further than the Plieades. All the components are blue white. Want to taste an “orange”? Then look again at Aldeberan, or Alpha Tauri, and say hello to a K spectrum star. Now that I have your curiosity aroused, would you like to see what our own Sun would look like? Then chose Alpha Aurigae, better known as Capella, and discover a spectral class G star that’s only 160 times brighter than the one that holds our solar system together! If you’re enjoying the game, then have a look at one of the most unusual spectral stars of all – Theta Aurigae. Theta is actually a B class, or a blue/white but instead of having strong lines in the helium, it has an abnormal concentration of silicon, making this incredibly unusual double star seem to glitter like a “black diamond”.

Still no luck in seeing color? Don’t worry. It does take a bit of practice! The cones in our eyes are the color receptors and when we go out in the dark, the color-blind rods take over. By intensifying the starlight with either a telescope or binoculars, we can usually excite the cones in our dark-adapted eyes to pick up on color. While you’re out tonight waiting on the meteor shower, try watching Orion. it contains several stars of different spectra! For the Southern Hemisphere, have a look at the Southern Cross as well. Awesome!

Tonight will also be the peak of the Sigma Hydrid meteor shower. With its radiant near the bright star, Procyon, this will make an nice “all hemispheres” type of show. But don’t hold your breath… The Sigma Hydrids are famous for being both notoriously fast and faint. With a predicted fall rate of about 3-12 per hour at maximum, this is not a spectacular show, but thanks to the new Moon tonight, you might stand a chance at catching a meteor that is normally only observed by the most serious of sky watchers.

Sunday, December 12 – Today the Moon at perigee and will be about 358,002 km or 222,452 miles away from Earth. If this make you feel like singing the “blues”, then why don’t we take advantage of dark skies and hunt down two very unique planetary nebulae tonight!

Our first will be the NGC7662, more commonly known as “The Blue Snowball”. Starting in the constellation of Andromeda, you will find this unique nebula by locating Iota and Omicron Andromedae and identifying the fifth magnitude star 13, about one-third the distance between them. The NGC7662 is approximately one-half a degree southwest. Shining at a decent magnitude 8, the “Blue Snowball” is achievable in large binoculars and very small telescopes, but due to its size, it will appear almost stellar. By upping the magnification you will find the NGC7662 to be a wonderfully blue “disc” that has a central star that can be spotted with larger telescopes. At around 5600 light years away, this unusual character is very similar to our next study!

Moving on to the constellation of Aquarius, recall our earlier study of the M2 and re-locate Beta. Now hop southwest to bright star, Nu. Only one degree west of Nu you will find the NGC7009, or the “Saturn Nebula”. Also shining at a magnitude 8, the NGC7009 can be spotted in large binoculars and small scopes, but requires the use of high power to understand “why” it is so named. Larger instruments will easily reveal that the NGC7009 has two extensions, or “lobes” that make it appear visually like the planet Saturn! As a high surface brightness object, its central star is also a extremely hot blue dwarf that emits a continuous spectrum. Large telescopes can reveal a substantial amount of detail in this particular planetary nebula, but most simply enjoy it for its unique shape and “electric” coloration. Best of luck!

(Be aware that the most prolific of all meteor showers – the Geminids – peaks on December 13. Observers may wish to start their vigil before dawn tomorrow! Full information will be provided in next week’s issue.)

Until next week fellow SkyWatchers, keep looking up and thinking – the Universe is out there waiting to be explored! Wishing you clear skies and light speed… ~Tammy Plotner

Posted on by Fraser Cain

What’s Up This Week – Nov 22 – 28, 2004

Monday, November 22 – How about taking time to study a bit of astronomy this morning before a busy work week begins? Before dawn, ultra-bright Venus commands the ecliptic plane. Just above it, blue star Spica and mighty Jupiter capture attention and dim, red Mars is below Venus. This is a wonderful sight for just the unaided eye, but why not try a challenge this morning? All it will require is binoculars and clear sky! For viewers in both hemispheres, (40 degrees and below) the time is perfect to locate Comet C/2003 K4 LINEAR as it slides just slightly south of visible star Beta Hydra. At an estimated magnitude of 5, it will be a beauty for the Southern Hemisphere and a challenge for the North!

Tonight’s lunar feature can be spotted in binoculars, but needs a telescope to be studied. The Riphaeus Mountains will appear to the southwest of Copernicus. Highlighted by the bright ring of Euler, the Riphaeus Mountains under high power show a variety of isolated hills and sharp peaks which may have been the original crater walls of Mare Cognitum before having been filled with lava flow. Northeast of this range is an area with a smooth floor on the border of Oceanus Procellarum. It is here that Surveyor 3 landed on April 19, 1967. After having bounced three times, the lunar probe came to rest on a smooth slope in a sub-telescopic crater. As its on-board television monitors watched, Surveyor 3 deployed the “first of its kind” miniature power shovel and dug to a depth of 18 inches. The revelation of sub-soil material and clean-cut lines allowed scientists to come to the conclusion that the loose lunar soil was capable of compaction. Watching as Surveyor 3 pounded its shovel against the surface, the tiny “dents” it produced answered the crucial question – the surface of a mare would support the landing of a spacecraft and subsequent exploration by astronauts.

In the mood to stay up late tonight? Then wait until well past midnight until Orion has risen well in the sky and let’s try for another comet despite the Moon. Comet C/2004 Q2 (Machholz) is visible to larger binoculars, but better achieved in telescopes for northern viewers 40 degrees and below. At around magnitude 8, it will appear on the Columba/Caelum border. Viewers in both hemispheres should enjoy this one!

Tuesday, November 23 – The first photograph of a meteor shower was taken on this day in 1885 in Prague, Czechoslovakia but no picture can rival the beauty of the predawn skies as Venus once again dominates the scene. While lovely Spica and Jupiter try to steal the show, try to ignore them as it’s time to start observing Mars (right below Venus) and watch in the coming days as they appear closer and closer together.

Weather satellite Tiros II was launched on this day in 1960. Carried to orbit by a three-stage Delta rocket, the “Television Infrared Observation Satellite” was about the size of a barrel, testing experimental television techniques and infrared equipment. Operating for 376 days, Tiros II sent back thousands of pictures of Earth’s cloud cover and was successful in its experiments to control orientation of satellite spin and infrared sensors. Oddly enough, a similar mission – Meteosat1- also became the first satellite put into orbit in 1977 on this day by the European Space Agency. Where is all this leading? Why not try observing satellites on your own! Thanks to a wonderful tool from NASA you can be alerted by email whenever a bright satellite makes a pass for your specific area. It’s fun!

Tonight’s lunar feature will be bright, medium-sized class one crater, Artistarchus. On the terminator tonight north of Keplar, this dazzling feature can sometimes be seen by the naked eye and with no problem in binoculars. For telescopic viewers, Aristarchus will offer up a splendid challenge as you are encouraged to look for a thin, bright thread that curls away from it. Named Schroter’s Valley, it is a sinous rille and the largest of its kind. It may have once been a lava drainage channel, for it bears similarities with our own terrestrial volcanic features.

Wednesday, November 24 –
Heads up! There will an occulation of a bright star tonight by an asteroid. Visible from the NE to SW United States, Asteroid 860 Ursina will occult HIP 11395 (magnitude 7). For more details, click here for an IOTA locater chart and prediction times.

Comet C/2001 T4 (NEAT) will make its closest approach to Earth at a distance of 8.190 AU. Dry fact or an observable reality? Comet T4 is indeed very visible to the northern hemisphere, but it is not for the faint of heart. Right now it is holding around a magnitude 11 and is cutting its way across the Draco/Bootes border, making it a prime target for early morning viewers when the Moon is as low as it can possibly be. Requiring at least 12.5 inches of aperture, T4 will closely resemble a small, out-of-focus globular cluster since the Moon will toast any indication of coma. Are you up to that kind of challenge? I dare ya…

Tonight’s highlighted lunar feature can be seen in binoculars but best viewed with a telescope. Located in the southwest quadrant and on the terminator just south of Shickard, crater Wargentin is most unique. Once upon a time, it was a very normal crater and had been that way for hundreds of millions of years – then it happened. Either a fissure opened in its interior, or the meteoric impact that formed it caused molten lava to begin to rise. Oddly enough, Wargentin’s walls were without large enough breaks to allow the lava to escape and it continued to fill the crater to the rim. Often referred to as “the Cheese”, enjoy Wargentin tonight for its unusual appearance!

Thursday, November 25 – Ready to aim for a bullseye? Then tonight as darkness completely falls, go have a look at the Moon. To the right of it will be the M45, or the Pleiades star cluster. Just below it you will note bright, reddish star, Aldeberan. Set your eyes, scopes or binoculars there and let’s look into the “eye” of the Bull.

Known early on as “Al Dabaran”, or “the Follower”, Alpha Tauri it took its name for the fact that it appears to follow the Pleiades across the sky. In Latin it was “Stella Dominatrix”, yet the old English knew it as “Oculus Tauri”, or very literally the “eye of Taurus”. No matter which ancient astronomy lore we explore, there is reference to Aldeberan. As the 13th brightest star in the sky, it almost appears from Earth to be a member of the V-shaped Hyades star cluster, but its association is merely coincidental since it is about twice as close to us as the cluster. In reality, Aldeberan is really on the small end as far as K5 stars go and like many other orange giants, could possibly be a variable. Aldeberan is also known to have five close companions, but they are faint and highly difficult to observe with backyard equipment. At a distance of approximately 68 light years away, Alpha is only about 40 times larger than our own Sun and approximately 125 times brighter. To get a grasp on that size, think of it as being about the same size as the Earth’s orbit! Because of its position along the ecliptic, Aldeberan is one of the very few stars of first magnitude that can be occulted by the Moon.

And speaking of Moon, let’s explore tonight’s lunar feature – Galileo. It is a challenge for binoculars to spot this feature, but telescopes of any size capable of higher power will find it easily on the terminator to the west, northwest section of the Moon. Set in the smooth sands of Oceanus Procellarum, Galileo is a very tiny, eye-shaped crater and has a soft rille that accompanies it. It was named for the very man who first viewed and contemplated the Moon through a telescope. No matter what lunar resource you chose to follow, all agree that giving such an insignificant crater a great name like Galileo is unthinkable! For those of you familiar with some of the outstanding lunar features, read this account of Galileo’s life and just look at how many spectacular craters were named for people he supported! We cannot change the names of lunar cartography, but we can remember Galileo’s many accomplishments each time we view this crater.

Friday, November 26 – Today is the fifth anniversary of the discovery of SAU 005 & 008 labeled “Mars Meteorites”. These meteorites are known to be of Mars origin because of gases preserved in the glassy material of their interior. They were hurled into space some 600,000 years ago when a probable asteroid impact on Mars tossed them high enough to escape the planet’s gravity and were captured by our gravity thousands of years later. These are just 2 of the 32 meteorites found on Earth positively classed from their chemical compositions to be of Martian origin.

Comet 32P Comas Sola will make its closest approach to the Earth at a distance of 1.237 AU, but is it visible? The answer is yes. At around magnitude 13, Comas Sola is within the range of large aperture telescopes, but viewing will be difficult tonight thanks to the full Moon. Now cruising the border of Cetus and Aries, 32P can be found very near Mu Cetus. If you cannot spot it tonight, try in just a few days when the later rise of the Moon will provide darker skies.

Since it will be bright tonight, why don’t we try doing something a little different with an astronomical twist? Earlier in the week we discussed watching satellites, so how about if we learn how and when to locate the International Space Station! It’s easy to discover visible passes of the ISS using tools like this link provides, and even more fun to watch them. There may be a pass that will occur tonight in your area, and you might have to wait a few days, but the tool is now in your hands to predict the sightings. If you are new to the astronomy game, it may take a few times before the numbers that determine the height of the pass make sense from where you view, but don’t be discouraged if you don’t spot it right away. A rule of thumb is an altitude value of 10 means it will be very low on the horizon, while one of 90 means it will pass directly overhead. It’s very exciting to follow with binoculars because you can make out a certain amount of detail and those talented enough to “track” with a telescope will see even more. Even if you just watch with your eyes, it’s still a wonderful event that folks of all ages enjoy. Happy Hunting!

Tonight’s full Moon is also known as the “Frost Moon” and there is little doubt about how its name came to be! For those of you interested in viewing lunar features tonight, libration will be favourable to study a collection of shallow, dark craters known as Mare Australe. Located on the southeastern limb, this large binocular and telescopic object is well-worth locating because it isn’t always visible to the degree it will be tonight.

Saturday, November 27 – Tonight Uranus is at opposition. No, this doesn’t mean the planet is causing an altercation in the heavens or joining a political party. It just means that Uranus has now reached the point in its orbit where its celestial longitude is precisely 180 degrees from that of the Sun. Here’s a tip: planets that have reached opposition are visible all night long!

Tonight, rather than adventure on the lunar surface, let’s turn our eyes to the far north and explore the constellation of Cassiopeia. Almost everyone is familiar with the legend of Cassiopeia and how the Queen came to be bound in her chair, destined for an eternity to turn over and over in the sky, but did you know that Cassiopeia holds a wealth of double stars and galactic clusters? Seasoned sky watchers have long been familiar with this constellation’s many delights, but let’s pretend that not everyone knows where they are all at and tonight let’s begin our exploration of this Cassiopeia with a two of its primary stars.

Looking much like a flattened “W” the southern-most bright star is Alpha. Also known as Schedar, this magnitude 2.2 spectral type K star, was once suspected of being a variable, but no changes have been detected in modern astronomy. Binoculars will reveal its orange/yellow coloring, but a telescope is needed to bring out its unique features. In 1781, Sir William Herschel discovered a 9th magnitude companion star and our modern optics easily separate the blue/white component’s distance of 63″. A second, even fainter companion at 38″ is mentioned in the list of double stars and even a third at 14th magnitude was spotted by S.W. Burnham in 1889. All three stars are optical companions only, but make 150 to 200 light year distant Schedar a delight to view!

Just north of Alpha is the next destination for tonight… Eta Cassiopeiae. Discovered by Sir William Herschel in August of 1779, Eta is quite possibly one of the most well-known of binary stars. The 3.5 magnitude primary star is a spectral type G, meaning it has a yellowish color much like our own Sun. It is about 10% larger than Sol and about 25% brighter. The 7.5 magnitude secondary (or B star) is very definitely a K-type, metal poor, and distinctively red. In comparison, it is half the mass of our Sun, crammed into about a quarter of its volume and around 25 times dimmer. In the eyepiece, the B star will angle off to the northwest, providing a wonderful and colorful look at one of the season’s finest!

Sunday, November 28 – Why not step outside this morning before dawn and have a look at Mars just below Venus on the horizon? This would be a fitting way to celebrate the 40th anniversary of the Mariner 4 launch. Mariner 4 gave us our first “up close and personal” looks of the planet’s surface as it beamed back 22 television pictures of Mars’ barren, dusty red surface. As we look at Mars this morning, think of all the changes that have occurred in its exploration in just 40 years!

Heads up for this evening! In a line from Greenland, through Canada, to the northwest United States, Asteroid 80 Sappho will occult HIP 19229 (7.9 magnitude). For the northeast to southwest United States, 64 Angelina will occult SAO093069(b) (magnitude 11.3) and then a bit later take out SAO093069(a) (magnitude 10) for the southeast/southwest United States. Be sure to click on the links for appropriate times and finder charts supplied by IOTA.

Thanks to just a slightly later rise of the Moon, let’s return again to Cassiopeia and start first by exploring the central most bright star, Gamma. At approximately 100 light years away, Gamma is a very unusual star. Once thought to be a variable, this particular star has been known to go through some very radical changes with its temperature, spectrum, magnitude, color and even diameter! Gamma is also a visual double star, but the 11 magnitude companion is highly difficult to perceive so close (2.3″) from the primary.

Four degrees southeast of Gamma is our marker for this starhop, Phi Cassiopeiae. By aiming binoculars or telescopes at this star, it is very easy to locate an interesting open cluster, NGC457, because they will be in the same field of view. This bright and splendid galactic cluster has received a variety of names over the years because of its uncanny resemblance to a figure. Some call it an “Angel”, others see it as the “Zuni Thunderbird”, I’ve heard it called the “Owl” and the “Dragonfly”, but perhaps my most favourite is the “E.T. Cluster”, As you view it, you can see why! Bright Phi and HD 7902 appear like “eyes” in the dark and the dozens of stars that make up the “body” appear like outstretched “arms” or “wings”. (For E.T. fans? Check out the red “heart” in the center.)

All this is very fanciful, but what is the NGC457, really? Both Phi and HD 7902 may not be true members of the cluster. If magnitude 5 Phi were actually part of this grouping, it would have to have a distance of approximately 9300 light years, making it the most luminous star in the sky, far outshining even Rigel! To get a rough of idea of what that means, if we were to view our own Sun from this far away, it would be no more than magnitude 17.5. The fainter members of the NGC457 comprise a relatively “young” star cluster that spans about 30 light years across. Most of the stars are only about 10 million years old, yet there is 8.6 magnitude red supergiant in the center.

No matter what you call it, the NGC457 is an entertaining bright cluster that you will find yourself returning to again and again. Enjoy!

Until next week? Keep looking up and enjoying the wonders of the night sky! Wishing you clear skies and light speed…

~Tammy Plotner

Posted on by Fraser Cain

What’s Up This Week – Nov 15 – 21, 2004

Image credit: NASA
Monday, November 15 – On this day in 1738, William Herschel is born in Hanover, Germany. He left for England at age 19 to work as a music teacher, but ended up devoting all his spare time to mathematics and astronomy. Building his own telescope, in 1774 he enlisted the aid of his sister Caroline (also an astronomer) and began exploring the cosmos. In 1781 he discovered a new planet which he named Georgium Sidus for the king, but we more commonly know it as Uranus. The king then appointed Herschel as his private astronomer allowing him to devote all of his time to study. He built a 48 inch (1.22 meter) aperture scope at Slough, which enabled his discovery of two moons belonging to Uranus and the sixth and seventh moons of Saturn. He also studied rotation of the planets – as well as the motion of double stars, cataloging more than 800 of them. Herschel’s studies of nebulae increased the numbers of the observed from 100 to 2500 and was the first to speculate they were comprised of stars. Knighted in 1816, Sir William Herschel is considered the founder of sidereal astronomy. Happy Birthday!

As darkness falls, the tender crescent Moon appears low in the southwest among the stars of teapot-shaped constellation, Sagittarius. Mercury may be visible to the west and much lower on the horizon.

Tonight this three-day old Moon will provide a splendid view of crater Cleomides. It’s a very old crater, and as a “Class Five” is thought to have experienced different degrees of lava flooding, or perhaps filled with ashes, during its formation causing it to be more shallow than its original depth. For those with stable skies and instruments capable of supporting high power, Cleomides also has a fine and beautiful rima that extends approximately 30 km across its northern floor.

Since the Moon will be well out of the way at an early hour, why not take the opportunity tonight to study a globular cluster? Located in the eastern part of the constellation of Capricornus, the M30 is about six degrees south of bright star Gamma and located in the field of view with 41 Capricorni. Found in August of 1764 by Charles Messier, most binoculars from a dark sky location will have little problem distinguishing this small globular cluster. Telescopes will enjoy the M30 for its bright beauty and fine resolving powers with larger instruments. At approximately 26,000 light years away, the core of M30 is extremely dense and believed to have suffered a core collapse, making its linear radius span approximately 139 light years. Any stars beyond that distance would escape the influence of the globular structure simply because of the Milky Way Galaxy’s tidal gravitational forces. As an added treat as you will discover 41 Capricorni (in the same field of view) is a double star!

Tuesday, November 16 – Venus will hold court 4 degrees north of the bright blue star, Spica, in the constellation of Virgo in the predawn eastern sky. Appearing with it will be Jupiter and faint red Mars forming nearly a straight line across the east-southeast. Spica will be above and to the right of Mars.

Tonight the four-day old Moon will provide the opportunity to note a very changeable and eventually bright feature on the lunar surface – Proclus. At around 28 km (18 miles) in diameter and 2400 meters (11,900 feet) deep, crater Proclus will appear on the terminator on the west mountainous border of Mare Crisium. Tonight Proclus will seem to be about 2/3 black, but 1/3 of the exposed crater will be exceptionally brilliant. The reason for this is that crater Proclus has an albedo, or surface reflectivity of about 16%, which is an unusually high value for a lunar feature. Watch this area over the next few nights as two rays from the crater will widen and lengthen, extending approximately 322 km (200 miles) to both the north and south.

Take the opportunity tonight to study an extremely fine, colorful star system that is wonderful in binoculars and outstanding in the telescope. Located northeast of previous study star Deneb, (and visible to the naked-eye) Omicron 1 Cygni (aka 31 Cygni) is a premier object. Its blue secondary stars contrast wonderfully with the brilliant gold of the primary. Omicron is a widely “spaced” system providing easy resolution with the most modest of optical aids. You’ll like this one!

November 17 – 19 – The annual Leonid meteor shower will be underway, but for those of you seeking a definitive date and time, it doesn’t always happen. The degree of the meteor shower itself belongs to the debris shed by comet 55/P Tempel-Tuttle as it passes our Sun in its 33.2 year orbital period. Although it was once assumed that we would merely add around 33 years to each observed “shower”, we later came to realize that the debris formed a cloud that lagged behind the comet and dispersed irregularly. With each successive pass of Tempel-Tuttle, new filaments of debris were left in space as well as the old ones, creating different “streams” that the orbiting Earth would cross through at varying times making blanket predictions unreliable at best.

Each year during November, we pass through these filaments – both old and new – and the chances of impacting a particular “stream” from any one particular year of Tempel-Tuttle’s orbit becomes a matter of mathematical equations. We know when it passed… We know where it passed… But will we encounter it and to what degree? Traditional dates for the peak of the Leonid Meteor shower occur as early as the morning of November 17 and as late as November 19, but what about this year? On November 8, the Earth passed through an ancient stream shed in 1001. Predictions ran high for viewers in Asia, but the results turned out to be a dud. There is no doubt that we crossed through that stream, but its probability of dissipation is incalculable. Debris trails left by the comet in 1333 and 1733 look the most promising this year. For November 19, Jeremie Vaubaillon, Esko Lyytinen, Markku Nissinen, and David Asher predict that U.S. observers will be favoured as we cross the trail at around 06:42 UT. Fall rates are not incredible (about 10 per hour) but observers in Asia are far more favoured as we encounter the second stream left in 1733 at around 21:49 UT. The predicted fall rate for this one jumps to a respectable 65 per hour.

We may never know precisely where and when the Leonids might strike, but we do know that a good time to look for this activity is well before dawn on November 17, 18 and 19th. With the Moon out of the way long before the radiant constellation of Leo rises, the chances are good of spotting one of the offspring of periodic comet Tempel-Tuttle. Your chances increase significantly by traveling a dark sky location, but remember to dress warmly and provide for your viewing comfort. If it is cloudy? Remember to try the simple trick of tuning an FM radio receiver to the lowest frequency that does not receive a clear signal and “listen” for the blips, beeps and bongs that signify meteor scatter!

Wednesday, November 17 – According to tradition, the peak of the Leonid meteor shower will occur this morning in the predawn hours. Since you have read the above explanation, you realize that we may not pass through the “stream” at this time and we just might! All predictions indicate a low level of activity – around 15 to 35 per hour – but if skies are clear? I’ll see you out there!

On this day in 1970, long running Soviet mission Luna 17 successfully landed on the Moon. Its Lunokhod 1 rover became the first wheeled vehicle on the Moon. Lunokhod was designed to function three lunar days but actually operated for eleven. The machinations of Lunokhod officially stopped on October 4, 1971, the anniversary of Sputnik 1. Lunokhod had traversed 10,540 meters, transmitted more than 20,000 television pictures, over 200 television panoramas and performed more than 500 lunar soil tests. Spaseba!

Tonight will also be a perfect opportunity to study crater Theophilus in either binoculars or telescopes. Located on the terminator and bordered on the northern edge by Mare Nectaris and the south by Mare Tranquillitatus, Theophilus has an average diameter of 105 km (65 miles) and contains a wonderful multiple mountain peaked center. This particular crater is unusual in the sense that the floor is parabolic. The interior may be dark, but you will see a bright point of light that is the summit of its huge central peak.

Using the Moon as our guide tonight, why not try to find Neptune once again? At 21h Neptune will be located just 5 degrees north or the Moon!

Thursday, November 18 – Be sure to get up extra early today in hopes of catching the Leonid meteor shower! (see above for predictions.) In the darkness before dawn, blue Spica appars to the right of bright Venus. Mars is below and Jupiter above. Mars will occult TYC 5561-00614-1 (11.7 Magnitude Star) and Mercury will occult TYC 6815-04687-1 (9.1 Magnitude Star). See link for times and areas.

Tonight’s outstanding lunar feature will be a pair of craters that you cannot miss – Aristotle and Eudoxus. Located to the north, this pair of Class 1 craters will be highly prominent in both binoculars and telescopes. The northernmost, Aristotle was named for the great philosopher and has an expanse of approximately 87 km. Its deep and rugged walls show a wealth of detail for high power and two small interior peaks. Companion crater to the south, Eudoxus, spans 67 km and offers up equally rugged details.

Although skies will be bright, you can still do a little bit of binocular study on a very fine asterism known as the “Coathanger”. The proper name is Collider 399, but the pattern of stars wonderfully resembles a coat hanger. It is easy located in the constellation of Vulpecula. Find previous study star, Albireo once again and the relatively bright star south of that is Alpha Vulpeculae. Just aim your binoculars there and enjoy the smiles it brings!

Friday, November 19 – Are the predawn hours going to be the peak of the Leonid meteor shower for 2004? We just don’t know for certain, but if skies are clear, I plan on observing again this morning! (Let’s see just how accurate those predications are…)

The First Quarter Moon occurs at 12:50 UT and Algol will reach minima at 07:22 UT today. The Moon will reach its maximum libration tonight of 8.4 degrees, permitting those of you interested a view of Gauss and Hahn on the northeastern limb. On this day in 1969, Apollo 12, the second manned mission to the Moon, lands safely in the Oceanus Procellarum (Ocean of Storms). Why not celebrate by observing our nearest astronomical neighbor tonight?

For binoculars and telescopes, the Moon will provide a piece of scenic history as we take an in-depth look at crater Albategnius. This huge, hexagonal mountain walled plain will appear near the terminator about one third the way north from the south limb. This 81 mile (136 km) wide crater is approximately 14,400 feet deep and the west wall will cast a black shadow on the dark floor. Albategnius is very ancient formation, filled partially with lava at one point in its development, and is home to several wall craters like Klein (which will appear telescopically on its southwest wall). Albategnius holds more than just the distinction of being a prominent crater tonight – it holds a place in history. On May 9, 1962 Louis Smullin and Giorgio Fiocco of the Massachusetts Institute of technology aimed a red laser beam toward the lunar surface and Albategnius became the first lunar object to be illuminated and detected by a laser from Earth!

On March 24, 1965 Ranger 9 took this “snapshot” of Albategnius (lower right) from an altitude of approximately 2500 km. Companion craters in the image are Pltomaeus and Alphonsus, which will be revealed tomorrow night. The Ranger 9 was designed by NASA for one purpose – to achieve a lunar impact trajectory and to send back high-resolution photographs and high-quality video images of the lunar surface. It carried no other scientific experiments, and its only destiny was to take pictures right up to the moment of final impact. It is interesting to note that Ranger 9 slammed into Alphonsus approximately 18.5 minutes after this photo was taken. They called that… A “hard landing.”

Tonight would also be a great time to re-locate Uranus. It’s only 4.1 degrees north of the Moon!

Saturday, November 20 – Today is Edwin Hubble’s 115th birthday! Born in 1889, U.S. astronomer Edwin Hubble, became the father of modern cosmology. His extensive list of accomplishments could fill pages, so please take the time to learn about one of the finest astronomers of our times.

Tonight’s featured lunar crater will be located on the south shore of Mare Ibrium right where the Apennine mountain range meets the terminator. Eratosthenes is a 37 mile (58 km) diameter and 12,300 foot deep unmistakable crater. Named after ancient mathematician, geographer and astronomer Eratosthenes, this splendid Class 1 crater will display a bright west wall and a black interior which hides its massive crater capped central mountain (3570 meters high!) tonight. Extending like a tail, a 50 mile long mountain ridge angles away to the southwest. As beautiful as Eratostenes appears tonight, it will fade away to total obscurity as the Moon becomes more full. See if you can spot it in five days!

After having looked at the Moon tonight, take the time out to view bright southern star – Formalhaut. Also known as “The Lonely One”, Alpha Pices Austrinis seems to sit in a rather empty area in the southern skies 23 light years away. At magnitude 1, this main sequence A3 giant is the southern-most visible star of its type to northern hemisphere viewers and it is the 18th brightest star in the sky. “The Lonely One” is about twice the diameter of our own Sun, but 14 times more luminous!

Sunday, November 21 – Mercury at greatest elongation east (22 degrees) of the Sun, appearing low in the southwestern sky after sunset, or try looking for it in the darkness just before dawn.

Tonight’s lunar feature can sometimes be spotted with only the naked eye. Located to the northern hemisphere of the Moon, the dark ellipse of crater Plato is unmistakable. Named after the famous philosopher, this Class 5 crater spans approximately 64 by 67 miles (101 km) but is a shallow 8000 feet deep. Plato’s floor is 2700 square miles of lava and has been studied for over 300 years. This crater has the distinction of being one of the only mountain-walled plains that doesn’t “disappear” as the Moon grows full! For those of you with very fine optics, or who wish a web cam challenge? Try finding Plato’s interior craterlets. Good luck!

For Southern Hemisphere viewers, tonight would be a wonderful opportunity to re-discover one of the finest double stars in the sky – Rigel Kentarus! Located low to the southwest, Alpha Centauri is the third brightest star in the sky, yet the most famous because it is the nearest star to our solar system at a distance of only 4.34 light years!

Until next week? Keep looking up! I wish you clear skies and light speed… ~Tammy Plotner

Posted on by Fraser Cain

What’s Up This Week – Nov 8 – 14, 2004

Image credit: Hubble
Monday, November 8 – Saturn turns retrograde on this date and today will be the closest approach of asteroid 4433 Goldstone to Earth at a respectable distance of 1.358 AU – or just 149,597,871 km. While asteroids of this nature are being closely monitored, they aren’t really observable to the majority of the amateur astro community. In case you’ve ever wondered just what it would be like to follow an asteroid, why not try your hand at locating and tracking one one of the brightest and easiest for beginners? Vesta!

Asteroid Vesta is considered to be a minor planet since its approximate diameter is 525 km (326 miles) wide, making it slightly smaller in size than the state of Arizona. Vesta was discovered on March 29, 1807 by Heinrich Olbers and it was the fourth such “minor planet” to be identified. Olbers discovery was fairly easy because Vesta is the only asteroid bright enough at times to be seen unaided from Earth. Why? Orbiting the Sun every 3.6 years and rotating on its axis in 5.24 hours, Vesta has an albedo (or surface reflectivity) of 42%. Although it is about 220 million miles away, pumpkin-shaped Vesta is the brightest asteroid in our solar system because it has a unique geological surface. Spectroscopic studies show it to be basaltic, which means lava once flowed on the surface. (Very interesting since most asteroids were once though to be rocky fragments left-over from our forming solar system!)

Studies by the Hubble telescope confirmed this, as well as a large meteoric impact crater which exposed Vesta’s olivine mantle. Debris from Vesta’s collision then set sail away from the parent asteroid. Some of them remained within the asteroid belt near Vesta to become asteroids themselves with the same spectral pyroxene signature, but some escaped through the “Kirkwood Gap” created by Jupiter’s gravitational pull and allowed these small fragments to be put into an orbit that would eventually bring them “down to Earth”. Did one make it? Of course! In 1960 a piece of Vesta fell to Earth and was recovered in Austrailia. Thanks to Vesta’s unique properties, the meteorite was definitely classified as once being a part of our third largest asteroid.

Now, that we’ve learned about Vesta, let’s talk about what we can see from our own backyards. As you can discern from the image, even the Hubble Space Telescope doesn’t give incredible views of this bright asteroid. What we will be able to see in our telescopes and binoculars will closely resemble a roughly magnitude 7 “star”, and it is for that reason that I strongly encourage you to visit Heaven’s Above, follow the instructions and print yourself a detailed map of the area. When you locate the proper stars and the asteroid’s probable location, mark physically on the map Vesta’s position. Keeping the same map, return to the area a night or two later and see how Vesta has moved since your original mark. Since Vesta will stay located in the constellation of Aquarius all month, your observations need not be on a particular night, but once you learn how to observe an asteroid and watch it move – you’ll be back for more!

Tuesday, November 9 – Remember last week when Jupiter and Venus did a spectacular morning dance in the sky? Well, the excitement hasn’t ended yet for now the Moon has joined the show. Before local dawn, Jupiter will be 1 degree to the lower right of the crescent Moon. For most of us, this beautiful “sky scenery” would be pleasure enough, but for those living in eastern Canada and the north-eastern United States, something just a bit more exciting is about to happen – the Moon is going to occult Jupiter during the daylight hours! Timing for such events is very critical and varies widely by location. To ensure success, please visit the International Occultation Timing Association (IOTA) for precise times in your area.

Asteroid 2000 JE5 will be performing a very near Earth fly-by today as it passes only 0.131 AU away. While that is less than the distance between Earth and the Sun, it is still 19,597,338 km or 12,177,221 miles away!

Thanks to dark skies, early tonight would be a great opportunity to use telescopes or large binoculars to study one of the finest of deep space objects, the “Ring” nebula. Located in the quickly westering constellation of Lyra and roughly halfway between bright stars Sheilak (Beta Lyrae) and Sulfat (Gamma Lyrae) this wonderful planetary nebula can be seen in small binoculars and comes to life with a telescope. But before we view the “Ring”, let’s learn a little more about the M57 and the two stars we’ll use to find it.

Beta is a variable star that averages around 3.38 magnitude at its maximum, but drops to around 4.1 at minima. This typical lyrid-type eclipsing variable is relatively easy to observe even without optical aid because nearby Gamma remains a constant magnitude 3.25. For a few days, both stars will appear to be about the same brightness, but about every 13 days, Sheilak will fade out to about half the brightness of Sulafat! For those of you aiming a telescope towards Gamma, you will find that it is a optical double star with a 10th magnitude companion.

Roughly halfway between these two interesting stars (but a bit closer to Beta) is tonight’s object. The M57 is a classic example of a planetary nebula first discovered by French astronomer Antoine Darquier in 1779 and cataloged only days later by Charles Messier. At approximately 2300 light years away, the “Ring” is basically the ejecta of a dying star. Many theories exist about the structure of the nebula itself , but popular opinion is that we may be looking through the shell, much like looking down the barrel of a gun. Its interior star has reached white dwarf stages, slowly shedding its mass and complex waves of ultra-violet radiation which fluoresce the rarefied gases of the nebula expanding at the gentle rate of around 19 km (12 miles) per second. The nebula itself exhibits many different spectral qualities as seen in photography, but what does it really look like?

To binoculars, the M57 will appear almost stellar in size, but the small disk lacks the properties of starlight. To the average telescope, the “Ring” will appear much as you see here – a softly glowing torus with a gentle grey/green color. At low power it is spectacular because the accompanying stellar field is so rich. Larger telescopes can resolve the central star under excellent sky conditions along with variances in the structure of the ring itself. Reach for the “Ring” tonight… You’ll be glad you did!

(In loving memory of Carl Sagan who was born on November 9, 1934. You were an inspiration to us all…)

Wednesday, November 10 – The early morning show continues as Jupiter, Venus, the very thin crescent Moon and Mars all appear with 20 degree of each other just before local dawn. For observers in other parts of the world, today is your day to observe an occultation as the Moon moves across Venus! The “footprint” for this occultation will be for skywatchers in Australia, New Zealand and Southern Asia. As always, timing is everything, so please visit IOTA for precise times for your locations. Observers with sense of curiousity and a large telescope might like to know that Mars will also occult an 11.8 magnitude star. (The challenge will be seeing how long you can follow the progress.) Information on this event is slim, but if you want to know where and when – here’s your clue.

This evening we are once again going to study a single star and it will help you become acquainted with the constellation of Perseus. Its formal name is Beta Persii and it is the most famous of all eclipsing variable stars. Tonight, let’s identify Algol and learn all about the “Demon Star”.

Ancient history has given this star many names. Associated with the mythological figure, Perseus, Beta was considered to be the head of Medusa the Gorgon, and was known to the Hebrews as Rosh ha Satan or “Satan’s Head”. 17th century maps labeled Beta as Caput Larvae, or the “Spectre’s Head”, but it is from the Arabic culture that the star was formally named. They knew it as Al Ra’s al Ghul, or the “Demon’s Head”, and we know it as Algol. Because these medieval astronomers and astrologers associated Algol with danger and misfortune, we are led to believe that Beta’s strange visual variable properties were noted throughout history.

Italian astronomer Geminiano Montanari was the first to note that Algol occasionally “faded” and its methodical timing was cataloged by John Goodricke in 1782, who surmised that it was being partially eclipsed by a dark companion orbiting it. Thus was born the theory of the “eclipsing binary” and it was proved spectroscopically in 1889 by H.C. Vogel. At 93 light years away, Algol is the nearest eclipsing binary of its kind and is treasured by the amateur astronomer for it requires no special equipment to easily follow its stages. Normally Beta Persii holds a magnitude of 2.1, but approximately every three days it dims to magnitude 3.4 and gradually brightens again. The entire eclipse only lasts about 10 hours!

Although Algol is known to have two additional spectroscopic companions, the true beauty of watching this variable star is not telescopic – but visual. The constellation of Perseus is well placed this month for most observers and appears like a glittering chain of stars that lay between Cassiopeia and Andromeda. To help further assist you, re-locate last week’s study star, Gamma Andromedae (Almach) east of Algol. Almach’s visual brightness is about the same as Algol’s at maxima. Tonight at 16:55 UT, Algol will be at minima and will appear approximately the same brightness of Alpha Trianguli. Depending on what time zone you live in, it would be possible for you to see Algol return to full brightness once again at 02:55 UT on November 11! If you are clouded out, don’t worry. Agol reaches minima again on November 13 at 13:44 UT, November 16 at 10:33 UT, November 19 at 7:22 UT, November 22 at 4:11 UT, November 25 at 1:00 UT, November 27 at 21:49 UT and November 30 at 18:38 UT. Just remember that it only takes 10 hours to complete its eclipse and enjoy the “Demon”!

Thursday, November 11 – Southern hemisphere viewers? You asked for it and you got it. This morning the Moon will occult Mars for East Africa and Australia! It was a bit difficult for me to find precise timing information for you, but I did locate at list of cities and times that you might find useful. Best of luck!

Uranus becomes stationary today and Comet P/1996 R2 (Lagerkvist) will make its closest approach to Earth today at a distance of 1.793 AU. At around magnitude 17, this would be one serious observing challenge!

Tonight let us take the opportunity to visit with another planetary nebula seen from a different perspective – “The Dumbbell”. You will want to start fairly early, because as with Lyra, the constellation of Vulpecula is fast declining. The M27 is challenging with small binoculars, readily apparent in larger ones and superior in even small telescopes. By using previously visited stars Altair and Albireo, look for four stars that form the constellation of Sagitta between them. On a good night, the “Arrow” is easy to recognize. By looking at this constellation, get in mind the distance between the arrow’s point, Gamma, and the first of the three stars that make the arrow’s tailfeathers. Using this as your measure, return to Gamma and move the same distance due north, and let’s learn about the M27!

The M27 was the first planetary nebula discovered by Charles Messier and cataloged on July 12, 1764. As we learned with the “Ring”, a planetary nebula is a star shedding its mass in a thin, cold field of hydrogen and helium gas illuminated by the energy of the star itself. It is the strong ultraviolet radiation that excites these rarefied gases to glow in the soft greenish-blue that our eyes can perceive in a spectral condition which can only exist in space – doubly ionized oxygen! The nebula lies about 1,000 light years away from us and is expanding at a rate of about 17 miles per second, meaning that it grows about one arc-second per century. If these figures are correct, it has taken about 50,000 years for the M57 to have reached it’s present size.

The Hubble Telescope reveals the M27 in all its glory. Instead of looking through the planetary’s shell as we did with the M57, we are looking at the entire structure itself. Larger telescopes will have no problem resolving out tenuous rifts, folds and concentrations in the lobes of the nebula, as well as embedded stars. The central star is also evident in larger telescopes and the outer shell named the Millikin 1976 is apparent in Earth based telescopes with an aperture of around 30″. But what about large binoculars and the average backyard telescope?

Don’t worry. The wonderful “dumbbell” shape first described by John Herschel is very there. The spectral qualities described above are easily seen in the most modest of instruments! The M27 is perhaps one of the finest of deep sky objects for the amateur, and tonight? It’s yours…

Friday, November 12 – This morning will mark the peak of the Southern Taurid meteor shower. The Earth will be entering the second “stream” of debris in the early morning hours. The Taurids have a predicted fall rate of 7 per hour, but thanks to their relatively slow speed (27 km or 17 miles per second) and a New Moon, they might produce spectacular results. Good luck!

Asteroid 33342 (1998 WT24) will make a near Earth fly-by as it passes on 0.097 AU away. Hey, wait a minute. That dry fact seems pretty close doesn’t it? Then let’s find out… 0.097 AU would be 14,511,006 km or 9,016,721 miles. That’s roughly 34 times further away than our Moon, yet less than half the distance to our nearest planet, Venus. In astronomical terms? That is close!

Tonight we continue with our planetary studies by finding another such nebula located within a deep-space object. The M15 is well positioned now in the constellation of Pegasus and we start by once again identifying the “Great Square”. Leading the constellation to the west of the square is bright star Epsilon Pegasi, or Enif. By focusing either small binoculars or your telescope on Epsilon, you will know if you have the correct star, for Enif appears gently red. From there, the M15 is an easy catch in binoculars about 4 degrees northwest (about one field of view) and will appear to modest powers (5X30) as a small, round fuzzy patch with a star caught on the edge. Now let’s use a telescope and learn about the M15 as we view it.

Discovered originally by Miraldi in 1746, the wonderfully compact globular cluster was rediscovered by Charles Messier in 1764. It is one of the richest of clusters with an intense, compact core region and ranks as the 12th brightest globular in the sky. Its thousands of stars are gathered in a huge ball spanning 120 light years across and approximately 40,000 light years from Earth, but the M15 has many surprises. It has well been known this particular globular cluster contains many variable stars and pulsars, as well as a planetary nebula. As a rich radio x-ray source, studies of the M15 revealed many neutron stars and made headlines when Chandra revealed the presence of a binary neutron star.

To the average telescope, is simply a beautiful compact globular cluster. Even small apertures will begin to resolve out individual stars. For those with larger telescopes, take the time to “power up” on the M15 and find the planetary amidst the awesome resolvability!

Saturday, November 13 – Double your pleasure, double your fun, as tonight we’ll view two star clusters instead of just one! It’s a Saturday night and what finer way to celebrate than to view one of the most impressive star clusters in our galaxy – the NGC869 and NGC884. This pair of rich galactic open clusters are a naked-eye object from a dark site, easily seen in the smallest of binoculars from urban locations and beyond compare when viewed with a telescope at lowest power.

The western-most of the pair is NGC869, also known as “h Perseii”. It contains at least 750 stars clustered in a brilliant mass spanning about 70 light years, and approximately 7,500 light years away from us. It’s eastern companion is NGC884, or “Chi Perseii”. The statistics are almost a match, but NGC884 only has about half as many stars – some being “super giants” over 50,000 times brighter than our own Sun! These twin clusters have only one major difference: NGC884 is approximately 10 million years old and the NGC869 is perhaps 5 million. The existance of these splendid clusters was cataloged as far back as 350 B.C. with both Ptolemy and Hipparchus noting their appearance – yet Messier never “discovered” them!

Be sure to check out Algol again tonight, it’s minima is at 13:34 UT. Mercury will also be occulted by the Moon today, but it is far to close to the Sun to observe.

Sunday, November 14 – Tonight the Moon is at perigee, or the closest in its elliptical orbit to Earth. The challenge this evening will be to spot the very slender two-day old crescent while it is at its closest – only 356,410 km (221,473 miles) away!

This would be extremely fitting as we observe the 35th anniversary of the Apollo 12 mission. At 11:20:00 a.m. EDT, from launch complex 34-A at Kennedy Space Center, Florida, the Apollo 12 left Earth on November 14, 1969 in the second manned space mission bound for the Moon.

For Southern Hemisphere observers, tonight would be a great opportunity to study the Small Magellanic Cloud. At 210,000 light years away, this near neighbor to the Milky Way will be apparent to the naked eye just north of Beta Toucanae. Easily viewed in binoculars and incredible in telescopes, the Small Magellanic Cloud is home to the rich globular cluster 47 Toucanae. As the second brightest globular cluster in the sky, 47 was once believed to be a star until the 1750’s when French astronomer Nicohlas Louis du Lacaille discovered its true nature.

Until next week? Keep looking up… I wish you clear skies and light speed!
~Tammy Plotner

Posted on by Fraser Cain

What’s Up This Week? Oct. 25 – 31, 2004

Monday, October 25 – The waxing Moon will dominate the early evening skies, but tonight is an excellent opportunity for binoculars and telescopes to explore crater Tycho. Named for Danish astronomer, Tycho Brahe, this fantastic impact crater will be very impressive in even the most modest of optical aids. Spanning 85 km (56 miles), this lunar feature is very prominent and unmistakable in the southern hemisphere of the Moon. Tycho’s highly conspicuous ray systems support its impact crater theory and span hundreds of kilometers across the lunar surface. Tycho is also one of the youngest of the major features at an astounding age of only 50 million years old!

On January 9, 1968 Surveyor 7 (the last lunar robot of its kind) landed quietly on Tycho’s slopes at sunrise. Because previous Surveyor missions had provided the Apollo program with all the data necessary to their goals, Surveyor 7’s presence was scientific only. Two weeks later, when the Sun set on the landing site, Surveyor 7 had provided over 21,000 photographs, determined physical and chemical properties associated with the Southern Highland area and recorded the laser beams aimed toward it from two seperate Earth observatories.

Tuesday, October 26 – Begin your astronomy day by getting up before local sunrise this morning to view the planets. No scope is necessary for this excercise, but it is time to become familiar with the positions of the planets for there will be some excitement involving them coming in the days and weeks ahead. Facing east before local dawn, Venus is unmistakable. Far outshining any star in the sky, Venus will be due east and not too far above the horizon. (note how much brighter Venus appears at -4.0 magntiude than -1.42 Sirius to the south.) Lower yet than Venus on the eastern front, and not nearly as bright is Jupiter. A bit more difficult to spot amoungst the bright stars of the winter constellations, (but not impossible for the novice) is Saturn. Seasoned skywatchers know Saturn is currently in Gemini, but what if you’re new to the game? Try doing this. While facing east, point your finger at Venus then extend your arm straight over your head and ever so slightly to the south. There you will see three “stars” of similar brightness – but only two of these are stars. Castor and Pollux are the two primary stars of the constellation of Gemini and will appear less than a fist’s width apart and slanted slightly from east/southest to north/northwest. About one fist width west and slighly to the south, you will see another “yellowish” star. That’s no star. You’ve just found Saturn! Now, go back to Jupiter and Venus and trace a line between all three and you will begin to understand the ecliptic plane. For rural viewers with a clear, dark and low horizon? A real challenge will be to spot tiny red Mars who is also back on the scene.

Tonight the very gibbous Moon will command the skies and give unaided observers an opportunity to use their imaginations.

Since the dawn of mankind, we have been gazing at the Moon and seeing fanciful shapes in the lunar features. Tonight as the Moon rises is your chance to catch “The Rabbit In The Moon”. The “Rabbit” is a compilation of all the dark maria. The Oceanus Procellarum forms the “ear” while the Mare Humorum makes the “nose”. The “body” is Mare Ibrium and the “front legs” appear to be Mare Nubium. Mare Serentatis is the “backside” and the picture is complete where Mare Tranquilitatus and Mare Fecunditatis shape the “hind legs” with Crisium as the “tail”.

See the Moon with an open mind and open eyes — and find the “Rabbit”!

For telescopes and binoculars, the lunar surface will provide a bright but superior view of crater Grimaldi. Named for Italian physicist and astronomer, Francesco Grimaldi, this deep grey oval is one of the darkest albedo features on the Moon – only reflecting about 6% of the light. Approximately 430 km (140-145 miles) long, it’s easy to spot along the terminator and just slightly south of the center of the lunar limb. Tonight is the best time to view its mountained walls, for they will disappear and Grimaldi will take on the appearance of a small mare in the light of the full Moon.

Now don’t miss tomorrow!

Wednesday/Thursday, October 27/28 – Tonight’s full moon is also known as the “Hunter’s Moon“, but bright Luna will become the hunted in the starry skies as Earth overtakes it with our shadow… A total lunar eclipse! Because the eclipse will occur across international date lines, we will leave a two day heading for this event. Beginning at 01:04UT (9:04 P.M. EDT) and ending appromately four hours later, the total eclipse offers a wonderfully inspiring event that does not require an optical aid to enjoy. Universe Today will be gathering together a group of astrocameras from around the world with a clear view of the eclipse. Can’t see it in person? Watch it on the Internet with us.

Wishing you all clear skies!

Friday, October 29 – With only a very short time until the Moon rises tonight, take this opportunity to acquaint yourself with the last star in the Summer Triangle – Altair. Facing southwest after local sunset, you will find bright star Alpha Aquilae about 2/3 the distance between the horizon and the zenith for most northern hemisphere skywatchers. As the 12th brightest star in the sky, Altair is also one of our nearest “neighbors” at only 16 light years distance. This main sequence white star is only about one and a half times the size of our own Sol, but nine times brighter. One of the most amazing facts about Altair is its rotation speed. Our own Sun takes 25.4 days to execute a complete orbit, but Altair does it in 6 1/2 hours. Wow!

And speaking of orbit?

On this day in 1961, Enos the chimp, (part of the Mercury-Atlas 2 mission which would attempt three circumnavigations of the Earth) rocketed into outer space and reached orbit. Although two malfunctions occurred during his flight, Enos continued to perform his required operations despite being repeatedly “shocked” instead of “rewarded”. When the Atlas rocket’s thruster system malfunctioned, Mission Control ended his flight after two complete orbits of the Earth. Three hours and 21 minutes after his flight began, Enos re-entered the Earth’s atmosphere and landed safely in the Atlantic Ocean. NASA elevated the chimp’s status to hero and thanks to Enos, mission managers now proclaimed space travel as “safe” for human astronauts!

Tonight’s lunar feature for telescopes and binoculars will be crater Langrenus. Named for Belgian Engineer and Mathematician, Michel Florent van Langren, crater Langrenus will be easily found along the terminator slightly south of center. Its 132 km (85 mile) expanse will appear shallow with a bright central peak.

Keep your binoculars and telescopes handy for later in the evening (21:00 UT), for as the Moon rises higher and higher in the sky, you will find M45 (more commonly known as the “Plieades”) only 1.7 degrees north of the Moon. Make note of the Plieades position, for we will visit it, and its history in two days.

Saturday, October 30 – Tonight many communities around the world will celebrate “Trick Or Treat”, but the real treat for adults will be to give your visitors a view through a telescope. Even if you do not celebrate the season, what’s in store is truly “eye candy” for all ages. Beautiful, bright and colorful, Beta Cygni is an excellent example of an easily split double star. As the second brightest star in the constellation of Cygnus, Albireo lies roughly in the center of the “Summer Triangle” making it a relatively simple target for even urban telescopes.

Albireo’s primary (or brightest) star is around magnitude 4 and a striking orangish color. Its secondary (or B) star is slightly fainter at a bit less than magnitude 5 and often appears to most as a violet blue. Their wide separation of 34.3″ make Beta Cygni an easy split for all telescopes at modest power and even larger binoculars. At approximately 410 light years away, this colorful pair shows a visual separation of about 4400 AU, or a bit over 400 billion miles. As Burnham noted, “It is worth contemplating, in any case, the fact that at least 55 solar systems could be lined up, edge-to-edge, across the space that separates the components of this famous double!”

For those of you who interested in staying up later to “Moon Watch” with telescopes or binoculars, tonight will be a great opportunity to catch Mare Crisium. During this particular phase, Crisium will be on the decline and the position of the terminator will make it appear as if a giant “bite” had been taken off the edge of the Moon.

As the Moon rises, you will notice that Selene is now forming a triangle with Aldebran (Alpha Tauri) and the M45 (the “Plieades”). For those of you with a sense of humor while you’re outdoors? Turn on your radio and imagine the voice of Orson Welles – because “War Of The Worlds” was broadcast on this date in 1938!

Sunday, October 31 – Happy Halloween! Tonight’s astronomical adventure will be about exploring an ancient and well reknowned star cluster associated with this holiday that we’ve kept track of all week — the Plieades! Easily found from a modestly dark site with the unaided eye, the Plieades can be spotted well above the north-eastern horizon within a couple of hours of nightfall. To average skies, many of the 7 bright components will resolve easily without the use of optical aid, but to telescopes and binoculars? The M45 is stunning…

First let’s explore a bit of history. The recogntion of the Plieades dates back to antiquity and it’s known by many names in many cultures. The Greeks and Romans referred to them as the “Starry Seven”, the “Net of Stars”, “The Seven Virgins”, “The Daughters of Pleione” and even “The Children of Atlas”. The Egytians referred to them as “The Stars of Athyr”, the Germans as “Siebengestiren” (the Seven Stars), the Russians as “Baba” after Baba Yaga, the witch who flew through the skies on her fiery broom. The Japanese call them “Suburu”, Norsemen saw them as packs of dogs and the Tonganese as “Matarii” (the Little Eyes). American Indians viewed the Plieades as seven maidens placed high upon a tower to pretect them from the claws of giant bears, and even Tolkien immortalized the stargroup in the “Hobbit” as “Remmirath”. The Plieades have even been mentioned in the Bible! So, you see, no matter where we look in our “starry” history, this cluster of seven bright stars has been part of it.

But let’s have some Halloween fun!

The date of the Plieades culmination (its highest point in the sky) has been celebrated through its rich history by being marked with various festivals and ancient rites — but there is one particular rite that really fits this occasion! What could be more spooky on this date than to imagination a bunch of Druids celebrating the Plieades midnight “high” with Black Sabbath? This night of “unholy revery” is still observed in the modern world as “All Hallow’s Eve” or more commonly as “Halloween”. Although the actual date of the Plieades midnight culmination is now on November 21 instead of October 31, why break with tradition? Thanks to its nebulous regions the M45 looks wonderfully like a “ghost” haunting the starry skies.

Treat yourself and your loved ones to the “scariest” object in the night. Binoculars give an incredible view of the entire region, revealing far more stars than are visible with the naked eye. Small telescopes at lowest power will enjoy the M45’s rich, icy-blue stars and fog-like nebulae. Larger telescopes and higher power reveal many pairs of double stars buried within its silver folds. No matter what you chose, the Plieades definately rocks!

(For those of you tempted to stay up later since Daylight Savings ends tonight? I’ll see you on the light side of the Moon as crater Hercules will be making a fine appearance.)

Until next week? Keep looking up! I wish you clear skies and light speed…~Tammy Plotner