Observing Archives

November 20, 2009December 24, 2015 by Tammy Plotner

Weekend SkyWatcher’s Forecast – November 20 -22, 2009

Greetings, fellow SkyWatchers! Yep. The Moon is back, but this weekend can still present some great opportunities for enjoying astronomy. If you’re up early or out late? Well, hey… The Leonid meteor shower is still producing activity! Why not take a few minutes to learn about a great variable star you can follow without optical aid or study a new lunar feature? There’s plenty to do for binoculars and small telescopes – and perhaps even a clever new study you haven’t looked at yet! Whenever you’re ready, I’ll see you in the dark…

Friday, November 20, 2009 – Today celebrates the birth of a significant astronomer, Edwin Hubble. Born on this date in 1889, Hubble became the first American astronomer to identify Cepheid variables in M31, which in turn established the extragalactic nature of the spiral nebulae. Continuing with the work of Carl Wirtz, and using Vesto Slipher’s redshifts, Hubble could then calculate the velocity–distance relation for galaxies. This has become known as Hubble’s Law and demonstrates the expansion of our universe.

Tonight we’ll pass the Moon and head just a little more than a fist-width west of the westernmost bright star in Cassiopeia, to have a look at Delta Cephei (RA 22 29 10 Dec +58 24 54). This is the most famous of all variable stars and the granddaddy of all Cepheids. Discovered in 1784 by John Goodricke, its changes in magnitude are not due to a revolving companion but rather the pulsations of the star itself.

Ranging over almost a full magnitude in 5 days, 8 hours, and 48 minutes precisely, Delta’s changes can easily be followed by comparing it to nearby Zeta and Epsilon. Upon reaching its dimmest point, it will brighten rapidly in a period of about 36 hours yet take 4 days to slowly dim again. Take time out of your busy night to watch Delta change and change again. It’s only 1,000 light-years away and doesn’t even require a telescope! (But even binoculars will show its optical companion.)

Saturday, November 21, 2009 – Tonight let’s go to the southern lunar cusp to identify two small but very nice craters. Using previous study Fabricus, continue south and look for the pair connected side-to-side rather than end-to-end.

This is crater Watt, with Steinheil intruding on it. Remember the distance traveled south from Fabricus to this pair and extend that distance even further south. Seen on the limb is crater Biela. If conditions are stable, you might pick up a tiny black point in Beila’s west wall, Biela C.

Before we retire to the shadows tonight, let’s study the small, open cluster NGC 225, located a finger-width northwest of Gamma Cassiopeiae (RA 00 43 42 Dec +61 47 00). This 7th magnitude collection has been described by some as looking like a sailboat. A fascinating name might be the ‘‘Metamorphosis Cluster,’’ since the southwestern region of the cluster looks like a butterfly asterism and, to the northeast is the caterpillar-like asterism. Although just barely detectable as an unresolved patch through binoculars on a dark night, tonight’s Moon means that magnification is needed just to make out its half-dozen brighter 9th magnitude members. Modest scopes should reveal two dozen stars to magnitude 12.

Sunday, November 22, 2009 – On the lunar surface tonight, the three rings of Theophilus, Cyrillus, and Catharina will emerge, but tonight let’s power up on Theophilus and see what we can find! The area just northeast of Theophilus—where Mare Tranquillitatis and Mare Nectaris join—is called Sinus Asperitatis.

Toward its center, you will see the remains of a once grand (nameless) crater holding the younger, sharper Torricelli in its center. Dropping back to Theophilus, just outside of its east wall, you will also find a young crater, Madler. As you head east across the northern shore of Mare Nectaris, look carefully for two partial rings. The northernmost is so eroded that it never received a name, while a slight, faint horseshoe marks all that remains of Daguerre.

Tonight let’s test our starhopping and observing talents by starting first with a beautiful double – Gamma Arietis. Now look about a fist-width east-southeast for dim little Pi. When you have Pi centered, move about half a degree southwest for an alternative catalog study—DoDz 1.

Although you might find this sparkling double handful of stars of little interest, think twice before you hop on. Although DoDz studies are far more scattered and less populous than most galactic clusters, it doesn’t make them less interesting. What you are looking at are basically the fossils of once active and more concentrated regions of stars. As the cluster has matured, the lower mass members have been stripped away and joined the general population. Known as a ‘‘dissolving cluster,’’ DoDz 1 is all that’s left of a far grander collection. Very ancient. . .yet still very beautiful!

Enjoy your celestial adventures!

This week’s awesome images are (in order of appearance): Edwin Hubble (widely used public image), Delta Cephei (credit—Palomar Observatory, courtesy of Caltech), Steinheil and Watt at limb (credit—Alan Chu), NGC 225 (credit—Palomar Observatory, courtesy of Caltech), Theophilus, Cyrillus, and Catharina (credit—Alan Chu) and Dolidze-Dzimselejsvili 1 (credit—Palomar Observatory, courtesy of Caltech). We thank you so much!

November 17, 2009December 24, 2015 by Tammy Plotner

Kid’s Astronomy: Celestial Birds Migrate West?

Hello, Cosmic Kids! As the seasons change, not only do the Earthly birds migrate, but so do the celestial ones. In the Northern Hemisphere, it’s not unusual to see large flocks of our feathered friends moving on to warmer climes, but did you know that there are bird constellations that are migrating, too? Instead of flying south for the Winter, these ancient avians are headed west…

Over the next few days just after sunset, the slender crescent Moon will glide silently between two constellations that represent birds and help you to locate them with ease. While you’re out, listen to the voices on the wind… “Look to the southwest for Aquila the Eagle. Perhaps you recognize it as is one of the three constellations from which we learned the stars of the Summer Triangle? Aquila was known to the Romans as Vultur volans the ‘Flying Vulture’. Now instead of flying high in the sky, it is headed west. Look for a straight line of three stars almost level with the horizon. The center and brightest of these three stars is Altair and they represent the Eagle’s wings. The head of the Eagle – Lambda – is a much dimmer star which stretches off to the southwest to stars from Altair. Its proper name is Al Thalimain, which means the two ostriches! But there’s still more… If you look again at Altair, whose Arabic name means ‘the bird’, you’ll see another fairly bright star to the south. That’s Beta, or better known as Alshain. In Arabic, it means falcon!”

“To the ancient Greeks, Aquila was thought of as the feathered servant of Zeus. It was the Eagle who was in charge of holding the god’s thunderbolts and doing his chores. Aquila was also considered by some cultures to be the great eagle who ate Prometheus’ liver for giving fire to humans! To the Indians, the line of three stars which includes Altair is thought to be the footprints of the god Vishnu. Some Asian traditions see the bright star Vega as the Weaving-Princess who married Altair, the shepherd. In the Chinese love story of Qi Xi, Niu Lang (Altair) and his two children (Beta and Gamma Aquilae) are separated forever from their wife and mother Zhi Nu (Vega) who is on the far side of the river, the Milky Way.”

“If your skies are dark early enough and you have an open western horizon, you can use your binoculars to look for a flight of ‘Wild Ducks’ headed west, too. You will find it just a little north and west of the head of the Eagle, Lambda. This compact, open star cluster is also known as Messier Object 11 or NGC 6705. While you may only see a few stars in this 220 million years old gathering of suns, the cluster proper contains almost 2900 stars. Full of yellow and red giant stars these ‘ducks’ aren’t just migrating, they’re speeding away from us at 22 kilometers per second!”

Now, let’s go a bit higher and take a look at big bird – Cygnus the Swan. Sometimes folks refer to this constellation as the Northern Cross because of its shape. Do you recognize it as also being a member of the Summer Triangle? The tail of the Swan is bright star Deneb, Arabic for ‘tail’. Deneb is a very young, bright blue supergiant star and you’ll see three stars in a row below it – Gamma in the center, Delta to the north and Epsilon to the south. Two stars west of Gamma is Beta – Albireo – the beak of the Swan. If you have a telescope or higher power binoculars, take a look! Albireo is really two stars. This is what is known as a binary star, and you’ll find the pair has a very noticeable orange and blue color contrast.”

“Is that all the birds in Cygnus? Not hardly. Although it is very hard to see optically, there is another feathered friend very close to Deneb… the Pelican Nebula! This neon night bird is filled with stars being born and clouds of gas evolving. The young stars inside the cloud are very active and their energy is turning the cold gas into hot gas, causing it to glow and spread outward. The ridge of cold gas being pushed away from the 2,000 light-year year distant warm gas cloud is called an ionization front. Dark dust clouds are what shapes Pelican’s eye and long bill, while the ionization front make up the curved shape of the head and neck.”

“So where did the Swan come from? There are many legends. To the ancient Greeks, Cygnus is Zeus in disguise, flying his way across the sky to win the heart of Leda, the mother of Helen of Troy and the Gemini twins. Perhaps Cygnus is Orpheus, who was placed in the sky along with his harp (Lyra) after he was murdered. In one myth, Cygnus is a friend of Phaethon, the son of Sun god Apollo, who crashed the sky chariot while driving along the Milky Way. It is said that Zeus turned Cygnus into a swan for his heroic attempts to save Phaethon from the starry river. Perhaps Cygnus is the son of Neptune – saved by his father who turned him into a swan before he was defeated by Achilles. But according to Chinese mythology, Cygnus is the magpie bridge. And you know what magpies are, don’t you? That’s right… Birds!”

If you don’t find the Aquila constellation and Cygnus tonight, keep trying. Over the next few days you’ll find the crescent Moon will help guide the way! And keep looking up…

Many thanks to these image resources: Mythical Figures (Credit: Uranometria Archives), Constellation Maps (Credit: Windows to the Universe, UCAR), Aquila and Cygnus Illustrations (Credit: SEDS and Stellarium), Wild Duck Cluster (Credit: NASA image gallery) and Pelican Nebula (Credit: Digitized Sky Survey/Charles Shahar).

November 16, 2009December 24, 2015 by Tammy Plotner

Leonids Light Up The Night – 2009 Leonid Meteor Shower Information

The annual Leonid Meteor Shower is about to light up the night… And the time to start watching is now. The year 2009 will not see a Leonid storm, but an outburst for sure. There are still some uncertainties regarding the time of maximum of the 1466 trail. For those of you seeking a definitive date and time, it isn’t always possible, but we can learn a whole lot about when and where to look.

The Leonid Meteor Shower belongs to the debris shed by comet 55/P Tempel-Tuttle as it passes our Sun in its 33.2 year orbit. Although it was once assumed it would simply be about 33 years between the heaviest “showers,” we later came to realize the debris formed a cloud which lagged behind the comet and dispersed irregularly. With each successive pass of Tempel-Tuttle, new filaments of debris are left in space along with the old ones, creating different “streams” the orbiting Earth passes through at varying times, which makes blanket predictions unreliable at best. Each year during November, we pass through the filaments of its debris – both old and new ones – and the chances of impacting a particular stream from any one particular year of Tempel-Tuttle’s orbit becomes a matter of mathematical estimates. 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.

So what can we expect this year? According to NASA’s 2009 predictions a significant shower is expected this year when Earth crosses the 1466-dust and 1533-dust ejecta of comet 55P/Tempel-Tuttle. According to J. Vaubaillon, the narrow (about 1-hr) shower is expected to peak on November 17, 2009, at 21:43 (1466) and 21:50 (1533) UT, perhaps 0.5 to 1.0 hour later based on a mis-match in 2008, with rates peaking at about ZHR = 115 + 80 = 195/hr (scaled to rates observed in 2008). E. Lyytinen, M. Maslov, D. Moser, and M. Sato all predict similar activity from both trails, combining to about ZHR = 150 – 300 /hr. P. Jenniskens notes that if the calculated trail pattern is slightly shifted in the same manner as observed before, then the 1533-dust trail would move in Earth’s path and its rates would be higher (the 1466-dust trail would move away). However, the 1533-dust trail is distorted in the models, and because of that it is not clear how much higher that would be. This remains a rare opportunity to study old dust trails from comet 55P/Tempel-Tuttle. In such old trails, the model of Lyytinen and Nissinen predicts wide trails, which can be tested by measuring the width of the outburst profile.

Let’s take a closer look at the at how the two centuries old trails will affect our observing, beginning with the one created in the year 1466. The exact same trail will be encountered again this year with its maximum rate of up to 115 meteors per hour occurring at 21:43 UT (may be 0.5-1hr later). “The trail will be much closer to the Earth, explaining why we expect a quite high zenith hourly rate.” say J. Vaubaillon (et al), “However the discrepancy between the expected time of maximum remains, as well as a general higher expected ZHR. Among the possible explanations are: sensitivity to initial conditions (given that the trail is 16 Rev. old) or change of cometary activity (impossible to verify unfortunately).”

But don’t count on only this single trail, because the year 1533 trail will encounter the Earth at almost the same time as the 1466 trail. Its maximum time of arrival is expected to be at 21:50 UT on the 17th of November, with a zenith hourly rate of 80 – for a combined rate of perhaps 200 meteors per hour. “The total level of the shower (ZHR~200/hr) was callibrated using the 2008 observations of the 1466 trail, but nothing is known from the 1533 trail. As a consequence, it will be very interesting to check.” comments Vaubaillon, “In particular there might be a difference of up to 1 hour between the 1466 and 1533 trail, or they might even be late together, giving us some insight about how well/poorly we know comet 55P’s orbit.”

Let’s take a closer look with 3D-view of the two trails may have evolved between 1466 and 2009…

Dr. Vaubaillon’s colleagues from MSFC (D. Moser and B. Cooke) pointed out that the best location to view the outburst caused by the 1466 and 1533 trails will be centered around India and includes: Nepal, Thailand, Western China, Tadjikistan, Afghanistan, Eastern Iran, South Central Russia, etc. Dr. P. Atreya (IMCCE), citizen of Nepal, is currently organizing an international Leonid observation campaign in his home country. This campaign will involve many amateurs and researchers from Nepal and other countries. The climate conditions in Nepal at this time of the year makes it an excellent spot.

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 19. Where do you look? For most of us, the best position will be to face east and look overhead. With the Moon out of the picture, even if you don’t see a huge amount of meteoric activity, chances are that even a few minutes of your time will bring a bright and happy reward!

Many thanks to John Chumack for sharing his early 2009 Leonid image and to NASA, Dr. Vaubaillon and colleagues for the illustrations and 3D animation!

November 13, 2009December 24, 2015 by Tammy Plotner

Weekend SkyWatcher’s Forecast – November 13-15, 2009

Planetary scientists Carolyn Porco. Via NASA/JPL.

Greetings, fellow SkyWatchers! It’s a dark sky weekend and for many of us, the weather scene is improving greatly. Are you ready to enjoy some astronomy? Then take the chance to get out in the early morning and admire the alluring dance of the “Old Moon in the New Moon’s Arms” as it silently changes planetary partners over the next few days and catch some bright and early Leonid meteors. You won’t need gigantic optics to enjoy this weekend’s studies as we have a look at some very impressive double stars, galaxies and open clusters. Dust off those optics! And meet me in the backyard….

Friday, November 13, 2009 – Start your day the astronomy way! Get up early and take a look at the pleasing pairing of Saturn and the Moon. On this date in 1990, Carolyn Porco was appointed leader of the imaging team for the Cassini mission to Saturn. Porco’s career as a planetary scientist is unsurpassed, and she is an expert on planetary ring systems. For all of you who look at Saturn’s rings with wonder, be sure to send your best to Porco; her undying love of astronomy began with observations just like yours!

Today is also the birthdate of James Clerk Maxwell. Born in 1831, Maxwell was a leading English theoretician on electromagnetism and the nature of light. Tonight let’s take a journey of 150 light-years as we honor Maxwell’s theories of electricity and magnetism and take a look at a star that is in nuclear decay—Alpha Ceti (RA 03 02 19 Dec +04 14 10). Its name is Menkar, and this 2nd magnitude orange giant is slowly using up its nuclear fuel and gaining mass. According to Maxwell’s theories of the electromagnetic and weak nuclear forces, W bosons must be produced in such circumstances, an extremely advanced line of thinking for the time. Without getting deep into the physics, simply enjoy reddish Alpha for the beauty that it is. Even small telescopes will reveal its 5th magnitude optical partner 93 Ceti to the north. It’s only another 350 light-years further away! You’ll be glad you took the time to look this one up, because the wide separation and color contrast of the pair make this tribute to Maxwell well worth your time!

Saturday, November 14, 2009 – This morning before dawn, look for the Moon as it nears beautiful, blue-white Spica. This date in history marks the discovery of what we now refer to as a ‘‘Trans-Neptunian Object’’—Sedna. In 2003 Brown, Trujillo, and Rabinowitz went into the history books for having observed the most distant natural Solar System body to date. The rethinking of what it means to be a planet that this discovery inspired would eventually spell the end to Pluto’s reign as our ninth planet! Also on this date in 1971, Mariner 9 became the first space probe to orbit Mars. Can you still spot the faint westering Mars at sunrise?

Tonight let’s have a look at one of the most elusive Messiers’ of all, as we head about two fingerwidths northeast of Eta Piscium in search of M74 (RA 01 36 42 Dec +15 47 00).

Discovered at the end of September in 1780 by Mechain, M74 is a real challenge to smaller backyard telescopes, even at magnitude 9. This near perfect presentation of a face-on spiral galaxy has low surface brightness, and it takes really optimal conditions to spot much more than its central region. Located 30–40 million light-years away, M74 is roughly the size of the Milky Way yet contains no central bar. Its tightly wound spiral arms contain clusters of young blue stars and traces of nebulous star-forming regions that can be seen in photos. Yet little more than vague concentrations in structure are all that can be seen, even in a large scope. But if the sky conditions are great, even a small telescope can see details! Add the slightest bit of light pollution and even the biggest scopes will have problems locating it. Don’t be disappointed if all you see is a bright nucleus surrounded by a small hazy glow. Just try again another time. Who knows what might happen? A supernova was discovered in 2002 by a returning amateur, and again in 2003 from the Southern Hemisphere. When it comes to M74, this is the very best time of year to try with a smaller scope!

Sunday, November 15, 2009 – Up early? Then check out the Moon as it slides its way along the ecliptic toward the Sun and passes Venus! It’s celebrating this day, for in 1738 on this date William Herschel was born. Among this British astronomer’s and musician’s many accomplishments, Herschel was credited with the discovery of the planet Uranus in 1781; detecting the motion of the Sun in the Milky Way in 1785; finding Castor’s binary companion in 1804; and he was the first to record infrared radiation. Herschel was well known as the discoverer of many clusters, nebulae, and galaxies. This came through his countless nights studying the sky and creating catalogs whose information we still use today. Just look at how many we’ve logged this year! For the next few days, let’s look toward Cassiopeia as we remember this great astronomer. . .

Herschel discovered many of the famous ‘‘400’’ objects in Cassiopeia just 2 days after his birthday in 1787. Begin by familiarizing yourself with the area between Delta and Epsilon Cassiopeia as we have a look at NGC 654. At magnitude 6.5, NGC 654 (RA 01 44 00 Dec +61 53 00) is achievable with binoculars but shows as nothing more than a hazy spot bordered by the resolvable star HD 10494. Yet, set a telescope its way and watch this diminutive beauty resolve. It is a very young open cluster, which has been extensively studied spectroscopically. Oddly enough, it did not cease the production of low-mass stars after the heavier ones formed and shows distinct polarization. Enclosed in a shell of interstellar matter, almost all of NGC 654’s stars have reached main sequence, and two have been identified as detached binaries.

Until next week, keep your eyes open as early Leonid meteors are beginning to streak across the morning skies! Wishing you clear and steady…

This week’s awesome images are (in order of appearance); Carolyn Porco (credit—NASA), Alpha Ceti (credit—Palomar Observatory, courtesy of Caltech), M74 (credit—R. Jay GaBany), Sir William Herschel (widely used public image) and NGC 654 (credit—Palomar Observatory, courtesy of Caltech). We thank you so much!

October 20, 2009December 24, 2015 by Tammy Plotner

Skies Sparkle For Both Hemispheres – The Annual Orionid Meteor Shower!

It’s not often that both hemispheres of the Earth get treated to an annual meteor shower, but in a matter of hours the complex Orionid stream is heading to dark sky your way! Where and when do you watch? Will it be as good as this year’s Perseids as filmed by John Chumack above? Try even better! Follow me…

We are now slipping into the stream of Comet Halley and one of the finest meteor showers of the year. If skies are clear tonight, this would be the perfect chance to begin observations of the Orionid meteor shower. But get to bed early and rise well before dawn to enjoy one of the year’s most reliable meteor showers. The offspring of Comet Halley grace the early morning hours as they return as the Orionid meteor shower. This dependable shower produces an average of 10-20 meteors per hour maximum, and best activity begins before local midnight on the 20th, and reaches its peak as Orion stands high to the south about two hours before local dawn the 21st. With only the tiniest crescent of a Moon gone in the early evening, this looks to be the year’s premier meteor shower!

Although Comet Halley has now departed the inner Solar System, its debris trail remains well organized – allowing us to predict when this meteor shower will occur. The Earth first enters the stream at the beginning of October and does not leave until the beginning of November. This makes your chances of “catching a falling star” above average! These meteors are very fast, and although faint, occasional fireballs do leave persistent trails.

For best success, get away from city lights. Face south-southeast in the northern hemisphere and almost overhead in the southern – then relax and enjoy the stars of the Winter Milky Way. The radiant is near Betelguese, but may occur from any part of the sky. The meteor watching experience is much more comfortable if you include a lawn chair, blanket, and thermos of your favorite beverage.

Orionid Meteor Shower – Key Points

The nights of October 21st and 22nd are the best times to watch.
Maximum hours rates are typically 20/hr and meteors are described as “fast”.
The radiant is at RA=06h20m, DEC=+16o, just above the left shoulder of Orion.
The average magnitude of an Orionid meteor is 3.

Clouded out? Don’t despair. You don’t always need eyes or perfect weather to keep the watch. Tune an FM radio to the lowest frequency that doesn’t receive a clear signal. An outdoor FM antenna pointed to the zenith increases your chances – but isn’t essential. Simply turn up the static and listen. Those hums, whistles, beeps, bongs, and occasional snatches of signals are distant transmissions being reflected off a meteor’s ion trail!

Sky Chart Courtesy of NASA.

October 16, 2009December 24, 2015 by Tammy Plotner

Request For Twilight Observations of U Scorpii

Further to AAVSO Alert Notice 367 and Special Notices 127 and 141, the AAVSO requests twilight observations of the recurrent nova U Scorpii prior to its solar conjunction in late 2009. These observations are in support of the long-term campaign by Dr. Bradley Schaefer (LSU) to catch this very fast nova during its rise.

AAVSO Special Notice #171: In 2008, the last ground-based observation of U Sco was made on 2008 November 2 (S. Kerr,
Glenlee, QLD, Australia). Observers are asked to do the best they can to observe U Sco as close to the Sun as possible. For this project, fainter-than observations are just as important as positive ones, and observers are asked to report all observations as promptly as possible via AAVSO WebObs.

For more information on the U Sco campaign and its science goals, please see the following URL: http://www.aavso.org/news/usco.shtml

U Sco is located at the following (J2000) coordinates:
RA:16:22:30.80, Dec: -17:52:43.0

Charts for U Sco may be plotted using AAVSO VSP: http://www.aavso.org/observing/charts/vsp/index.html?pickname=U%20Sco

(AAVSO Special Notice was prepared by M. Templeton)

Located north of Antares, U Scorpii is one of the most famous recurrent novae… and one of the fastest known. Able to shoot up to 8 or 9 magnitudes in less than 6 hours, dedicated observers are predicting that 2009 should see this cataclysmic variable star erupt with a vengeance. “I’ve calculated that the recurrent nova U Scorpii, north of Antares and east of the head of Scorpius, should explode any month now.” says Bradley E. Schaefer of Sky & Telescope, “My ‘crystal ball’ is based on old archival photographs and data from amateur astronomers. This brings a golden opportunity for amateurs and professionals to catch the early hours of a nova eruption and to prepare in advance for an intensive observing campaign.”

While professional observatories and NASA’s Swift Satellite will be busy gathering information about any possible eruption, there’s more than enough room for amateur observations. While it’s great to have modern equipment and credited astronomers to capture the action, their eyes can’t watch 24/7 – and chances are good that any outburst may very well be captured by ordinary viewers working in the field. “Amateurs provided essentially the whole light curves for the last three eruptions.” says Brad, “Now, with some advance warning to allow preparations, and with a little luck, the upcoming eruption of U Sco could produce the best record of a nova outburst — of any kind — ever.”

Please promptly report all observations to the AAVSO with the name “U SCO”.

October 16, 2009December 24, 2015 by Tammy Plotner

Weekend SkyWatcher’s Forecast – October 16-18, 2009

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Greetings, fellow Stargazers! Were you up early this morning? If so, you were greeted by an awesome scene, much like this one captured by Danilo Pivato. There’s nothing more eyecatching the a close appearance of Venus and the Moon! With dark skies this weekend, it will be a good opportunity to broaden your astronomical horizons by chasing lesser known objects in both binoculars and telescopes. Of course there are challenges, too! Whenever you’re ready, I’ll see you in the back yard….

Friday, October 16 – Celestial scenery alert! Be up and outside this morning before dawn. The incredible duo of Venus and Saturn will be joined by the Moon! In 1982, the 30th return of Halley’s Comet was observed with the 5-meter (20000) Hale Telescope at the Mount Palomar Observatory. The comet was beyond the orbit of Saturn!

Tonight let’s head toward the region of Cas A and see what we can find. Although Cas A is itself not visible in amateur equipment, it is known to be associated with a 10,000-light-year-distant supernova remnant related to an unnoticed event occurring more than 300 years ago. The remnant itself has now expanded to a region filling some 10 light-years of space and has been imaged using orbiting X-ray observatories.

The closest deep-sky study to Cas A is the dense and compact open cluster NGC 7510 (RA 23 11 00 Dec +60 34 00). This diminutive, magnitude 7.9 study can just be glimpsed as a hazy patch in large binoculars and small scopes, with a few of its brightest 10th magnitude members resolvable at higher magnifications. Doubling the aperture brings out a dozen or so of NGC 7510’s 12th magnitude stars against the teeming glow of numerous fainter members. Double the aperture again, and 60 stars to magnitude 14 are possible. Many amateurs have discovered that the combination of a small rich field refractor, a 600 apochromatic refractor, and a 1200 Newtonian makes for the ultimate in observing equipment. But don’t forget those binoculars!

Saturday, October 17 – Today we mark the birth of Dr. Mae C. Jemison, the first black woman to go into space! Tonight let’s revisit M39 and use it as our touchstone to seek out other deep-sky gems. Starting with M39, head less than two finger-widths east-southeast (RA 21 53 32 Dec +47 16 06) to a 7.2 magnitude open cluster, one associated with the 12th magnitude ‘‘Cocoon Nebula.’’

Collectively known as IC 5146, this cluster with nebulosity consists largely of 12th magnitude stars and is just about mid-sized. Barely detectable in a small scope, this 4,000-light-year-distant cluster needs aperture to come out and play. Large scopes may make seeing the nebula possible, although an appropriate filter may be necessary from most observing sites. To assist in finding the Cocoon, look for the stream of the dark obscuration nebula B168 touching its eastern frontier.

Returning again to M39, head two finger-widths southwest in the direction of Deneb to seek 6.8 magnitude IC 1369 (RA 21 12 06 Dec +47 44 00). Mid-sized instruments will show a dozen or so 12th and 13th magnitude members within a misty haze of those waiting to be resolved. Also known as alternative catalog study Pechue (AN 3259), IC 1369 has been studied for luminosity features.

Sunday, October 18, 2009 – Tonight it’s a New Moon! Time to break out the muscle and challenge big telescope users to hone their skills. It’s galaxy-hunting time, and our destination for tonight is the Hickson Compact Group 87 (RA 20 48 11 Dec -19 50 24).

Several billion years ago, on the ecliptic plane about 4 degrees west/southwest of Theta Capricorni, and around 400 million light-years from our Solar System, a galactic association decided to form its own ‘‘Local Group.’’ Orbiting around a common center every 100 million years, their mutual gravity is pulling each of them apart, creating starbursts and feeding their active galactic nuclei. Small wonder they’re shredding each other. They’re only 170,000 light-years apart! One day HCG 87 may even form a single elliptical galaxy bright enough for the average telescope to see, but as they are now, this group isn’t going to be seen with anything less than 20 inch aperture.

So, shall we try something a little more within the realm of reality? Then go ahead and drop about 8 degrees south of Theta, and try picking up on the NGC7016/17/18 group (RA 21 07 20 Dec -25 29 15). Are they faint? Of course! It wouldn’t be a challenge if they were easy, would it? With an average magnitude of 14, this tight trio known as Leavenworth 1 is around 600 million light-years away. They’re very small and not very easy to locate, but for those who like something a bit different, give it a try!

Until next week? Dreams really do come true when you keep on reaching for the stars!

This week’s awesome images are (in order of appearance): The Moon and Venus: Courtesy of Danilo Pivato of Northern Galactic, NGC 7510, IC 5146, IC 1369, Hickson Compact Group 87 and NGC 7016/17/18 (credit—Palomar Observatory, courtesy of Caltech). We thank you so much!

October 9, 2009December 24, 2015 by Tammy Plotner

Weekend SkyWatcher’s Forecast – October 9-11, 2009

Greetings, fellow SkyWatchers! It’s a much darker weekend – and just in time for the Draconid Meteor Shower! If you haven’t been watching the early morning trio of Venus, Mercury and Saturn, there’s still time… Just as there is time to chase a couple of Caldwell Objects and a very challenging galaxy study for more practiced observers. But we’re not forgetting small scopes and binoculars either as we take a look at “What was Charles Messier thinking when he recorded M73?” It’s time to turn your eyes to the skies and I’ll see you in the dark…

Friday, October 9, 2009 – Have you been watching our early morning planetary conjunction? Mercury was nearly touching Saturn 24 hours ago! If you’re up early over the next few days, enjoy celestial mechanics in action as Venus, Mercury and Saturn slowly shift their positions in the sky.

Tonight is the peak of the northern Draconid meteor shower, whose radiant is near the westering constellation of Hercules. This particular shower can be quite impressive when comet Giacobini–Zinner passes near Earth. When this happens, the fall rate jumps to 200 per hour and has even been known to reach 1,000. Comet Giacobini–Zinner reached perihelion on July 2, 2005, passing within 8 million kilometers of Earth but has now greatly distanced itself from our region of the Solar System. Chances are the Draconids will produce only about 3–5 meteors per hour, but this number can vary.

Tonight’s skies remain dark into the early hours, so let’s take this opportunity to have a look at two objects from one of the more obscure catalogs. Set your sights on Alpha Pegasi, and drop due south less than 5 degrees to pick up NGC 7479 (RA 23 04 56 Dec +12 19 23).

Discovered by William Herschel in 1784, this 11-magnitude barred spiral galaxy experienced a supernova as recently as 1990. Although the 16th magnitude event near its nucleus is no longer visible, modest telescopes will easily pick out the bright core and elongation of the central bar. Larger aperture will find this one a real treat, as the spiral arms curl over and under the central structure, resembling a ballet dancer en pointe.

Congratulations! If you’ve found it, you’ve just observed Caldwell 44.

NGC 7814 is easy enough to find. Start at Gamma Pegasi and use the finderscope to center on a star around 3 degrees northwest (RA 00 03 14 Dec þ16 08 43). In the scope, look southeast to see NGC 7814 as a scratch of light in the low power field. Magnify and enjoy! This galaxy has a deeply concentrated nucleus and a very prominent dissecting dark dust lane. This one is also known by another name, Caldwell 43.

Saturday, October 10, 2009 – On this date in 1846, William Lassell was busy at his scope as he made a new discovery, Neptune’s moon Triton. Although our everyday equipment can’t ‘‘see’’ Triton, we can still have a look at Neptune! You’ll find it on the ecliptic around 21:45 in right ascension. On this date 140 years later (1986), a tiny asteroid, Asteroid 3753, was found orbiting Earth. Named Cruithne, the little body will orbit our Earth for at least another 5,000 years from a minimum distance of 15 million kilometers. While time and the stars appear to stand still, and astronomical twilight begins earlier each night, let’s take one last look at the exiting constellation of Sagittarius. Our return study for this evening is a telescopic challenge for skilled observers only. Set your sights about 2 degrees northeast of easy double 54 Sagittarii and around 7 degrees west of Beta Capricorni (RA 19 44 58 Dec –14 48 11), and let’s have a look at NGC 6822.

Often referred to as ‘‘Barnard’s Galaxy’’ for its discoverer (E.E. Barnard, 1884), this unusual customer is actually a member of our local galaxy group. For the 400–600 telescope, this 11th magnitude, 1.7-million-light-year-distant object will not be easy to see, but it can be achieved with good conditions. Lower power is essential in even larger scopes, and those into the 1200–1600mm range will see NGC 6822 burst into stunning resolution. Barnard’s Galaxy almost appears like an open cluster overlaid with nebulosity, but the experienced eye will clearly see that the ‘‘shine’’ behind the stars is galactic in nature. It’s a very clumpy and unusual galaxy, one that you will very much enjoy. Be sure to look for the small, pale blue, 10th magnitude planetary nebula NGC 6818 in the same field to the north-northwest. This pair rocks!

Sunday, October 11, 2009 – Today we begin with the 1758 birth on this day of Heinrich Olbers, a German astronomer who calculated the orbit of the 1779 comet, discovered the minor planets (asteroids) Pallas (1802) and Vesta (1807), and discovered five comets during his career. Tonight we’ll have a look at a collection of stars as we ponder the age-old mystery of M73. Located about three finger-widths north-northwest of Theta Capricorni (RA 20 59 00 Dec –12 38 00), this 9th magnitude open cluster consisting of four stars was discovered by Charles Messier on October 4, 1780. Messier described it as a ‘‘cluster of three or four small stars, which resembles a nebula at first glance. . ..’’ Hotly debated as to whether or not the grouping is a genuine cluster or simply an asterism, it was also included in J. Herschel’s catalog (GC 4617) and given the NGC 6994 designation by Dreyer. In 1931, Collinder cataloged M73 as Cr 426, with an estimated distance of 12,000 light-years. Still, the debate about its authenticity as a physically related group continues.

At least two stars show the same proper motion, leading scientists to believe that M73 may be the remnant of a much older and now dispersed cluster—or simply two related stars. Of the 140 stars
investigated in the region, 24 may be real members, including those in Messier’s original observation. Thanks to the work of Hertzsprung and Russell, these candidates fall within the color-magnitude diagram of a 2–3-billion-year-old cluster with Messier’s suspect four being evolved giants. Although more recent data indicate that M73 may simply be an asterism—sharing no common proper motion— you can still enjoy this unusual Messier in even a small telescope!

Until next week? Dreams really do come true when you keep on reaching for the stars!

This week’s awesome images are (in order of appearance): NGC 7479 and NGC 7814 (credit—Palomar Observatory, courtesy of Caltech), NGC 6822 (credit—Local Group Galaxies Survey Team/NOAO/AURA/NSF), Heinrich Olbers (historical image) and M73 (credit—Palomar Observatory, courtesy of Caltech). We thank you so much!

October 2, 2009December 24, 2015 by Tammy Plotner

Weekend SkyWatcher’s Forecast – October 2-4, 2009

Greetings, fellow SkyWatchers! Are you ready to catch the planetary action? Then get thee out into the night, because right now is the perfect time of year to catch all of our solar system bodies in the same day! Be sure to be out on Saturday night, too… Because it’s “Harvest Moon”! Need a little bit more of a challenge? Then fly off to Cygnus as we take a look at two of its most beautiful (and challenging) double stars! Whenever you’re ready, I’ll see you in the dark…

Friday, October 2, 2009 – It’s that time of year! Time to be able to see all the planets in 24 hours! If you’re able to get up before sunrise, it’s a good time to watch celestial mechanics in action as Mercury, Venus, and Saturn are beginning to draw together just before dawn. Be on the lookout for Mars nearly overhead. Now is a good time to see details.

If you haven’t spotted Uranus yet, let the Moon be your guide tonight for finding it about 5 degrees south. Even with bright skies, you should be able to distinguish its faint greenish disk from surrounding stars. What of Neptune? The blue world is a bit further from the Moon tonight on the ecliptic, and you’ll find it around 21:45 in right ascension. The last is the mighty Jove. For binoculars and telescopes, Jupiter is definitely the king of the observable planets for detail. Not only can you spot its different zones and equatorial belts, but refractor users can also regularly distinguish the faded Great Red Spot and other fine features, such as white ovals. For all larger apertures, be on the lookout for the moons! It’s very exciting to watch a shadow transit or to catch a Galilean as it reappears from behind the limb. In just a matter of a few hours, Jupiter’s details can change greatly!

For those who still cheer for Pluto’s status as a planet? The tiny god of the underworld still holds its place in our Solar System. . .and the sky! You can find it during the early evening around 18:02 in right ascension. Good luck on your planet quest!!

Saturday, October 3, 2009 – When the Universal Date changes tonight, the Moon will become full, and this will be the one closest to the autumnal equinox. Because the Moon’s orbit is more nearly parallel to the eastern horizon, it will rise near dusk for the next several nights in a row. On the average, the Moon rises about 50 minutes later each night, but at this time of year it’s around 20 minutes later for mid-northern latitudes and even later further north. Because of this added light, the name ‘‘Harvest Moon’’ was coined; it allowed farmers more time to work in the fields.

Often times we perceive the Harvest Moon as being more orange than at any other time of the year. The coloration is caused by the scattering of the light by particles in our atmosphere. When the Moon is low, like now, we get more of that scattering effect, and it truly does appear more orange. The very act of harvesting itself produces more dust, and often times that coloration will last the whole night through. And we all know the size is only an ‘‘illusion’’. . .

So, instead of cursing the Moon for hiding the deep-sky gems tonight, enjoy it for what it is, a wonderful natural phenomenon that doesn’t even require a telescope!

Sunday, October 4, 2009 – This date in 1957, the USSR’s Sputnik 1 made space history, as it became the first man-made object to orbit Earth. Earth’s first artificial satellite was tiny, roughly the size of a basketball, and weighed no more than the average man. Every 98 minutes it swung around Earth in its elliptical orbit. . .and changed everything. It was the beginning of the ‘‘Space Age.’’ Take the time with your children or grandchildren to check Heaven’s Above for visible passes of the International Space Station (ISS), and think about how much our world has changed in just over half a century!

Tonight we’ll begin with an easy double star and make our way toward a more difficult one. 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 has 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 blue, almost violet. The pair’s wide separation of 3400 makes Beta Cygni an easy split for all telescopes at modest power, and even for larger binoculars. At approximately 410 light-years away, this colorful pair has a separation of about 4,400 Astronomical Unit (AU). 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!’’

Now let’s have a look at Delta (RA 19 44 58 Dec +45 07 50). Located around 270 light-years away, Delta is a more difficult binary star. Its duplicity was discovered by F. Struve in 1830, and it is a very tough test for smaller optics. Located no more than 220AU away from the magnitude 3 parent star, the companion takes anywhere from 300 to 540 years to orbit its star and is often rated as dim as 8th magnitude. If skies aren’t steady enough to split it tonight, try again! Both Beta and Delta are on many challenge lists.

Until next week? Ask for the Moon… But keep on reaching for the stars!

This week’s awesome images are (in order of appearance): Solar System Montage (credit—NASA), Saguaro Moon (credit and copyright—Stefan Seip (NASA/APOD), Sputnik Archival Image, Beta Cygni: Albireo (credit—University of Nebraska-Lincoln) and Delta Cygni (credit—Palomar Observatory, courtesy of Caltech). We thank you so much!

September 25, 2009December 24, 2015 by Tammy Plotner

Infrared Moonset

When it comes to the Moon, there are times when I feel like the “Queen of Selene”. In just a few short weeks there will be a whole new style of lunar observing book out on the market, and just when I thought I’d heard it all and seen it all… along comes something new! While the header photograph on this article is absolutely spectacular, you’re going to go about your day (and night) smiling if you stop to take a look at what’s inside…

After spending an entire weekend with close friend, professional astronomer and member of the USGS team – Brent Archinal – who has been mapping out the information from the LRO, I’ve been in a real “Moon” mindset. Even our UT articles have seemed to have been geared towards our nearest astronomical neighbor, too! So, it just stands to reason that others might be feeling the call of lunacy as well. As it just so happens, one of the most prolific, dedicated and innovative astrophotographers I know – Joe Brimacombe – wasn’t cursing the Moon for re-appearing this month… He was celebrating it. Using a variety of techniques, he’s captured one of the most unique sets of sequences I’ve ever seen and I just had to share it with you!

“On the 20th September 2009 a crescent Moon set over the mountains behind Cairns and was captured in all its glory from Coral Towers Observatory using a variety of infrared cameras.” said Dr. Brimacombe, “These recordings not only show a majestic Moonset, but also the dramatic retrograde motion of the Moon against the fixed background of stars over a mere six minute period.”

This is simply one of those videos that were too good to go left unnoticed. Not only did it appeal to my scientific side, but it totally restored my faith that others can not only be creative and innovative – but know how to have fun, too!

I hope you enjoyed…

“Infrared Moonset” photo and video are courtesy, credit and copyright of Joe Brimacombe – Southerngalactic Imagers.