Posted on by Tammy Plotner

Lupus

Lupus

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Located south of the ecliptic plane, the constellation of Lupus was once associated with Centaurus, but was listed as a separate constellation in Ptolemy’s Almagest. It survived to become one of the 88 modern constellations recognized by the International Astronomical Union. Lupus covers around 334 square degrees of sky and contains 9 stars in its asterism with 41 Bayer Flamsteed designated stars confined within its area. It is bordered by the constellations of Norma. Scorpius, Circinus, Centaurus, Libra and Hydra. Lupus can be seen by all observers located at latitudes between +35° and ?90° and is best seen at culmination during the month of June.

In mythology, Lupus represents the Wolf and was once thought to represent the wild African dog associated with the mythical first king of Arcadia. The stars were only a representation of some type of creature – a beast – caught by the Centaur and about to be slain. Actually, no animal even entered the picture until Ptolemy called it Lupus and the Latin translation transformed it from the “beast” into a wolf!

Let’s start our binocular tour of Lupus with Alpha Lupi – the “a” symbol on our map. Known as Men, the “Star of Fortune” is a Beta Cephii variable star located about 550 light years from Earth. Its magnitude changes happen every 6 hours and 14 minutes – just like clockwork – but they aren’t very radical. Even a sharp-eyed observer isn’t likely to notice a .03 stellar magnitude drop in this blue giant star! But pay a little closer attention. Do you see a companion there? Even though it’s only an optical double star, it helps to make Men just a little bit more interesting!

Now turn your binoculars towards Beta Lupi – the “B” symbol on our map. Kekouan is also a blue giant star and is similarly distant at about 525 light years from our solar system. It’s another one of those hot class B stars that shine in that wonderful blue/white light and part of the expanding “Upper Centaurus Lupus” (UCL) OB association. What would it be like if it were closer? Try 13,600 brighter than our Sun. It’s a subgiant right near the end of its life and very near to becoming a red supergiant star…. and one day… a supernova!

Travel on in binoculars to the next star in the Association – Gamma Lupi – the “Y” symbol on our map. Gamma’s proper name is Thusia, meaning “The Sacrifice”, but the only thing you’ll have to sacrifice is a moment of your time to take a look through the telescope, because Thusia is a binary star. Located 567 light years from Earth, the blue/white primary is a giant star in its own right, accompanied by a very close companion whose orbit takes it nearly edge on from our perspective with a maximum separation of about .68″. Also try your luck with Epsilon Lupi, the “E” symbol. It, too, is a close binary star with about the same separation and 3.5 and 5.5 magnitude components.

Keep the telescope handy to look up NGC 5824 (RA 15:03:58.5 Dec -33:04:04). Located about 105 light years from where you’re reading, this globular cluster was first discovered by James Dunlop and recovered independently by E.E. Barnard. At around magnitude 9 and a little on the small side, you’ll find it relatively bright with a slightly off-centered, concentrated core region and a bit of resolvability around the edges for larger aperture.

Try your hand at planetary nebula IC 4406 (RA 14:22:26 Dec -44:09:04) too. This bi-polar nebula often goes by the popular name “The Retina Nebula” and will appear almost square because of the angle on which we see it. Chances are, it’s a hollow cylinder, just like all torus shaped planetaries – we just happen to be catching it from the side. At magnitude 10, it’s not going to wow you like the Hubble images will, but it is still a very worthy target for a larger telescope that will show a little detail.

Small, rich field telescopes and larger binoculars will be happy to take a look at NGC 5822 (RA 15:05.2 Dec -54:21). Spanning 40 arc minutes and shining away at magnitude 7, this well populated open cluster is so huge it will appear like a star cloud. Don’t be fooled into thinking your resolving it when you’re picking out foreground stars! NGC 5822’s population runs into the hundreds and its members average around stellar magnitude 13 and fainter. It will be hard to pick out from the rich Milky Way Galaxy star fields!

Don’t leave the telescope until you’ve tried galactic cluster NGC 5749 (RA 14 48.9 Dec -54 31). In a low power eyepiece, this star cluster will look like a just a loose group of stars which almost blend with the background star field. Containing around 35 members with the brightest about magnitude 10, keep to lower magnification to keep the target in site!

Cutting through our Milky Way galaxy at a rough angle of about 18 degrees is a disc-shaped zone called Gould’s Belt. Lupus is part of this area whose perimeter contains star forming regions which came to life about 30 million years ago when a huge molecular cloud of dust and gas was compressed – much like in the Orion area. In Lupus we find Gould’s Belt extending above the plane of the Milky Way!

Locate Theta Lupi and head around five degrees west for NGC 5986 (RA 15 46 03 Dec 37 47 10), a 7th magnitude globular cluster which can be spotted with binoculars with good conditions. While this Class VII cluster is not particularly dense, many of its individual stars can be resolved in a small telescope. Now sweep the area north of NGC 5986 (RA 17 57 06 Dec 37 05 00) and tell me what you see. That’s right! Nothing. This is dark nebula B 288 – a cloud of dark, obscuring dust which blocks incoming starlight. Look carefully at the stars you can see and you’ll notice they appear quite red. Thanks to B 288, much of their emitted light is absorbed by this region, providing us with a pretty incredible on-the-edge view of something you can’t see – a Barnard dark nebula.

Now let’s have a look at some things gravitationally bound as we start at Eta Lupi – the “n” symbol on our map. Eta is a fine double star which can even be resolved with binoculars. Look for the 3rd magnitude primary and 8th magnitude secondary separated by a wide 15″. You’ll find it by starting at Antares and heading due south two binocular fields to center on bright H and N Scorpii – then one binocular field southwest (RA 16 00 07 Dec 38 23 48).

When you are done, hop another roughly five degrees southeast (RA 16 25 18 Dec 40 39 00) to encounter the fine open cluster NGC 6124. Discovered by Lacaille and known to him as object I.8, this 5th magnitude open cluster is also known as Dunlop 514, as well as Melotte 145 and Collinder 301. Situated about 19 light-years away, it will show as a fine, round, faint spray of stars to binoculars and be resolved into about 100 stellar members to larger telescopes. While NGC 6124 is on the low side for northern observers, it’s worth the wait for it to hit its best position. Be sure to mark your notes, because this delightful galactic cluster is a Caldwell object and a southern skies binocular reward!

Source: Wikipedia
Chart courtesy of Your Sky.

Posted on by Tammy Plotner

Libra

Libra

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Libra is a constellation of the zodiac, positioned on the ecliptic plane between between Virgo to the west and Scorpius to the east. It is a faint group of stars and not easy to recognize. Its two major stars once once represented the claws of Scorpius. How and when it came to be recognized by its present designation is unknown. Libra covers approximately 538 square degrees of sky and contains 6 stars in its asterism. There are 46 Bayer Flamsteed designated stars within Libra and it is bordered by Serpens Caput, Virgo, Hydra, Centaurus, Lupus, Scorpius and Ophiuchus. Libra can be seen by all observers at latitudes between +65° and ?90° and is best seen at culmination during the month of June.

In mythology, the Alpha and Beta stars of Libra once represented Chelae Scorpionis, the northern and southern claws of the Scorpion. Who knows exactly where and when it became depicted as a set of scales, but the Romans identified it with the scales held by Astraea, the goddess of justice. They believed the Moon was in Libra when Rome was founded and the astrological sign represented balance because this is where the Sun was housed during autumnal equinox. Oddly enough, Libra is the only astrological symbol that doesn’t depict some type of living creature.

Once you’ve located it, let’s take a binocular tour of Libra, beginning with Alpha Librae – Zubenelgenubi – the “a” symbol on our map. Despite its alpha designation, it’s not the brightest star here, but what you’ll find here is a wonderful, visual double star. Alpha Librae “The Southern Claw” is located approximately 77 light years from the Sun, and the components are easily separated with even the slightest visual aid. Look for a beautiful yellow coloration to the spectral type A3 primary star and a slight blue tinge to the far fainter type F4 companion. Zubenelgenubi is close to the ecliptic so it can be easily occulted by the Moon!

Now, hop to Beta Librae – Zubeneschamali – the “B” symbol on our map. “The Northern Claw” is actually the brightest star in Libra and also one of the furthest away at about 160 light years from Earth. Beta Librae is a blue dwarf star of spectral type B8, what would appear to be a rather ordinary main sequence star – but take a really close look in binoculars. Does it appear a little green to you? Zubeneschamali is running a high temperature – more than twice that of our own Sun – produces light with a simple spectrum. This makes it a perfect candidate for examining interstellar gas and dust which lay between us and it – but its rapid hydrogen fusion also causes it to appear a little more green than other stars. A color rarely seen in stars! What’s more, Beta Librae spins about 100 times faster than our Sun and shines about 130 brighter. Not bad for a star that not even as evolved as Sirius!

Point your binoculars further south for Sigma Librae – the “O” symbol with the little flag on our map. Its traditional name is Zubenhakrabi – a cool class M (M3) rather-luminous red giant. Located approximately 292 light years from our solar system, Sigma is rather special – a prototype of its own group of ultra-small-amplitude variables which are called Sigma Librae variable stars. What are they? Pulsing red giants, of course! It doesn’t change its brightness much, maybe only 0.16 magnitudes over a 20-day period, but knowing you’re looking at dying solar mass star, with a dead helium core, fueled by internal nuclear-burning shells of helium and hydrogen is still undeniably fascinating! What’s Zubenhakrabi future like? Chances are it will just eventually become a Mira-type variable star that will eventually shed its outer skin, leaving its now-content carbon-oxygen center to become just another of the white dwarf stars of the night!

Time to get out the telescope and head for NGC 5694 (RA 14:39:36.5 Dec -26:32:18). This 10th magnitude, irregularly shaped globular cluster was discovered by Sir William Herschel in 1784 and is one of the more remote globular clusters of the Milky Way Galaxy at a distance of about 113 thousand light years. If you find it difficult to resolve, you’d be right. Its brightest stars average about magnitude 16 and so far none of them have been discovered to be variable. Why bother if it is so dim? Because this globular cluster is a curiosity! It’s moving… and it’s moving fast. According to studies, NGC 5694 can either be a hyperbolic orbit or may be elevated into a higher energy orbit during its evolution. It is possible that NGC 5694 may have once belonged to the Magellanic Clouds. Thanks to work done by Lee (et al) who discovered one red giant star, we know that it has a “unique chemical abundance pattern” and an “an extragalactic origin”. No wonder it’s so faint….

Need a big telescope challenge? Then try NGC5792 (RA 14:58.4 Dec -01:05). At around magnitude 12, it’s going to take some dark sky to catch this nearly edge-on spiral galaxy, but it is worth your time and trouble. As part of the Herschel catalog, you’ll find a distracting star on the western edge, but very pretty spiral galaxy structure with a bright nucleus await you. At 85 million light years away, it still shows some very nice form to large aperture.

Before you put away your telescope, try NGC 5903/5898 (RA 15:18.6 Dec -24:04). This binary elliptical galaxy pair is quite achievable in an 8″ telescope with dark skies and good seeing conditions. You’ll find them about three degrees northeast of Sigma, and just north of a pair of 7th magnitude stars. While northernmost NGC 5903 seems to be nothing more than a faint elliptical with a brighter concentration toward the center and an almost identical elliptical – NGC 5898 – to the southwest, you’re probably asking yourself… Why the big deal over two small ellipticals? First off, NGC 5903 is Herschel III.139 and NGC 5898 is Herschel III.138…two more to add to your studies. And second? The Very Large Array has studied this galaxy pair in the spectral lines of neutral hydrogen. The brighter of the pair, NGC 5898, shows evidence of ionized gas which has been collected from outside its galactic realm – while NGC 5903 seems to be running streamers of material toward its neighbor. A double-galaxy, double-accretion event! But there’s more… Look to the southeast and you’ll double your pleasure and double your fun as you discover two double stars instead of just one! Sometimes we overlook field stars for reasons of study – but don’t do it tonight. Even mid-sized telescopes can easily reveal this twin pair of galaxies sharing “their stuff,” as well as a pair of double stars in the same low power field of view. (Psst…slim and dim MCG 043607 and quasar 1514-241 are also here!) Ain’t it grand?

Tip the “scales” in your favor if you have a big telescope and get a good star chart. There’s lots more in Libra than you think!

Source: Wikipedia
Star Chart Courtesy of Your Sky.

Posted on by Tammy Plotner

Moon, Venus and Jupiter Dazzle on December 1

Venus, Jupiter and Moon - Shevill Mathers

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Are you ready for some spectacular sky scenery tonight? Then keep your fingers crossed for clear weather as the slender crescent Moon, Venus and Jupiter provide one of the finest sky shows we’ve seen all year – a conjunction in the west to dazzle the eye and boggle the brain! But just exactly why does seeing bright planets draw together command our attention? Step inside and let’s find out…

“Your eye is like a digital camera,” explains Dr. Stuart Hiroyasu, O.D., of Bishop, California. “There’s a lens in front to focus the light, and a photo-array behind the lens to capture the image. The photo-array in your eye is called the retina. It’s made of rods and cones, the fleshy organic equivalent of electronic pixels.” Near the center of the retina lies the fovea, a patch of tissue 1.5 millimeters wide where cones are extra-densely packed. “Whatever you see with the fovea, you see in high-definition,” he says. The fovea is critical to reading, driving, watching television. The fovea has the brain’s attention. The field of view of the fovea is only about five degrees wide.” Tonight, Venus, Jupiter and the crescent Moon will all fit together inside that narrow angle, signaling to the brain, “this is worth watching!”

When it comes to our eyes, almost every photoreceptor has one ganglion cell receiving data in the fovea. That means there’s almost no data loss and the absence of blood vessels in the area means almost no loss of light either. There is direct passage to our receptors – an amazing 50% of the visual cortex in the brain! Since the fovea doesn’t have rods, it isn’t sensitive to dim lights. That’s another reason why the conjunctions are more attractive than the surrounding starfields. Astronomers know a lot about the fovea for a good reason: it’s is why we learn to use averted vision. We avoid the fovea when observing very dim objects in the eyepiece.

Let’s pretend we’re a photoreceptor. If a light were to strike us, we’d be “on” – recording away. If we were a ganglion cell, the light really wouldn’t do much of anything. However, the biological recorder would have responded to a pinpoint of light, a ring of light, or a light with a dark edge to it. Why? Light in general just simply doesn’t excite the ganglion, but it does wake up the neighbor cells. A small spot of light makes the ganglion go crazy, but the neighbors don’t pay much attention. However, a ring of light makes the neighbors go nuts and the ganglion turns off. It’s all a very complicated response to a simple scene, but still fun to understand why we are compelled to look!

Many of us have been watching the spectacle draw closer over the last several days. How many of you have seen the Venus and Jupiter pair appear one over the top of each other – looking almost like a distant tower with bright lights? What we’ve been observing is Kepler’s Laws of Planetary Motion in action – and it’s a great way to familiarize yourself with celestial mechanics. What’s happening tonight is called a conjunction. This is a term used in positional astronomy which means two (or more) celestial bodies appear near one another in the sky. Sometimes the event is also called an appulse.

No matter what you call it, what you’ll see tonight is a worldwide happening and will look hauntingly like a “happy face” painted on the early evening sky. Don’t miss it!

Our deepest appreciation goes to Shevill Mathers for his dedication in getting this shot to share with us, and all the rest of the great astrophotographers at Northern Galactic and Southern Galactic who have also gave it their best shot! There can be only one…

Posted on by Tammy Plotner

Weekend SkyWatcher’s Forecast – November 28-30, 2008

Greetings, fellow SkyWatchers! Are you ready for a bit of a challenge this weekend? Then break out the big telescope and let’s go galaxy hunting in Cetus as we have a look at Hickson Compact Group 16. If you’d like to try something a little easier, then “monkey” around with planetary nebula, NGC 246! Got binoculars or a small scope? Then take on NGC 247 – it’s big, bright and beautiful! When ever you’re ready, I’ll see you out under the stars….

Friday, November 28, 2008 – Tonight in 1659, Christian Huygens was busy at the eyepiece – but he wasn’t studying Saturn. This was the first time any astronomer had seen dark markings on Mars! If Huygens and Herschel were alive to enjoy today’s new technology, you could bet they’d have a big backyard scope aimed about four degrees east of the Zeta-Chi pairing in Cetus to have a look at Hickson Compact Galaxy Group 16 (RA 02 09 31 Dec -10 08 59).

Consisting of four faint, small, galaxies designated as NGCs 835, 833, 838, and 839 clustered around a 9th magnitude star, these aren’t for average equipment – but are a true challenge for a seasoned observer. Groups of galaxies such as Hickson 16 are believed to be some of the very oldest things in our Universe – and this particular assemblage has a reputation for having an extremely large amount of starburst activity. It is also close enough for scientists to study. Its members were all discovered and cataloged by Sir William Herschel on this very night – 223 years ago! The northernmost, NGC 833, is known as H II.482, roughly of magnitude 13, followed by NGC 835 (H II.483) which holds a magnitude of 12. Next in line is NGC 838 (H II.484) at close to magnitude 13, followed by southernmost NGC 839 (H II.485) at magnitude 13. Not easy… But this beautiful crescent of four is worth the effort. If Herschel could do it – so can you!

Saturday, November 29, 2008 – Today in 1961 Enos the Chimp launched into fame! His story is a long and colorful one – but Enos was a true astronaut. Selected to make the first American orbital animal flight only three days before the launch, he flew into space on board Mercury-Atlas 5 and completed his first orbit in just under 90 minutes. Although Enos was scheduled to complete three orbits, he was brought back due to “attitude difficulties.” But whose? Malfunctions caused the chimp to be repeatedly shocked when performing the correct maneuvers, but Enos continued to perform flawlessly – and was said to run and jump enthusiastically on board the recovery ship, shaking the hands of the crew.

Although he died a year later from an unrelated disease which could not be cured at the time, Enos the chimp remains one of our most enduring space heroes. Tonight let’s monkey around with a planetary nebula as we’ll take a look at 8th magnitude NGC 246 about five degrees north of Beta Ceti.

On the large side as planetaries go, this variegated shell of gas envelops a dying star about 1600 light-years away. Once upon a time, the star was much like our Sun, but over thousands of years its atmosphere expanded, interacting with the gas and dust in the interstellar medium to create what you see tonight. With the outer shell visible to even small telescopes, larger aperture can spot the fainter member of the binary at the heart of this planetary…a star well on it’s way to becoming a white dwarf.

Discovered by Sir William Herschel, it is often referred to as the “Skull” nebula, but perhaps tonight you’ll see the smiling face of Enos forever leaving its mark on space!

Sunday, November 30, 2008 – Just as a curiosity, on this day in 1954, Elizabeth Hodges was struck by a five kilogram meteorite in Alabama. Duck! If you’re out at sunset tonight, you’ll be struck by the beauty of the slender crescent Moon illuminated by Earthshine. Not far away, look for the pairing of Venus and Jupiter, because things are going to get a lot cozier as the last month of the year begins!

Before the Moon once again interferes with study, last take one last look at Cetus before we move on. Our last target is a beauty – one which can be seen with larger binoculars, is easy with a small telescope, and becomes breathtaking with large aperture. Set your sights on bright Beta and drop less than three degrees south-southeast for NGC 247 (RA 00 47 09 Dec -20 45 38)…

As one of the largest members of a group of galaxies located around our galactic south pole, NGC 247 seems to be standing still in space – at a distance of six to eight million light-years. At its core is a near stellar-sized nucleus – a bright, central mass of stars which dominates its patchy looking structure. Look closely at its northern edge, for NGC 247 sports a huge area of dark, obscuring dust – or what may just be an empty space between its clouds of stars. Note a bright star caught on its southern flank.

While you may find this low surface brightness galaxy a bit difficult unless you stick with the most minimal of magnification, you can not only congratulate yourself for capturing another Herschel “400” object, but Bennett 3 as well.

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

This week’s awesome photos are: Hickson 16 – Credit: Palomar Observatory, courtesy of Caltech, Enos (and handler) – Credit: NASA, NGC 246 (south is up) – Credit: Palomar Observatory, courtesy of Caltech and NGC 247 – Credit: Palomar Observatory, courtesy of Caltech. We thank you so much!

Posted on by Tammy Plotner

Weekend SkyWatcher’s Forecast – November 21 – 23, 2008

Greetings, fellow SkyWatchers! Are you ready for the weekend? It’s Friiiiiday and it’s time to make a date with the Queen as we gather up a few more studies in the great constellation of Cassiopeia. Since we’ve got some dark skies ahead of us, expect to be a little more “challenged” this time! For you Messier fans, break out your telescope and go fishing in Pisces for the awesome M74 – but don’t sell this week’s observing article short. Are you looking for an alternative catalog study that you may not have seen? Then step outside and let’s find one…

Friday, November 21, 2008 – Tonight we will haunt Cassiopeia one last time – with studies for the seasoned observer. Our first challenge of the evening will be to return to Gamma where we will locate two patches of nebulosity in the same field of view. IC 59 and IC 63 are challenging because of the bright influence of the star, but by moving the star to the edge of the field of view you may be able to locate these two splendid small nebulae. If you do not have success with this pair, why not move on to Alpha? About one and a half degrees due east, you will find a small collection of finderscope stars that mark the area of NGC 281 (RA 00 52 25 Dec +56 33 54). This distinctive cloud of stars and ghostly nebulae make this NGC object a fine challenge!

NGC 185
NGC 185
NGC 147
NGC 147

The last things we will study are two small elliptical galaxies that are achievable in mid-sized scopes. Locate Omicron Cassiopeiae about seven degrees north of M31, and discover a close galactic pair that is associated with the Andromeda group – NGC 185 (RA 00 38 57 Dec +48 20 14) and NGC 147 (RA 00 33 11 Dec +48 30 24).

The constellation of Cassiopeia contains many more fine star clusters and nebulae – and even more galaxies. For the casual observer, simply tracing over the rich star fields with binoculars is a true pleasure, because there are many bright asterisms best enjoyed at low power. And scopists will return year after year to “rock with the Queen.” Enjoy its many challenging treasures tonight!

Saturday, November 22, 2008 – 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 Dec +15 47).

Discovered at the end of September, 1780, by Méchain, 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 to 40 million light-years away, M74 is roughly the size of the Milky Way, yet has 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 some vague concentrations in structure are all that can be noted visually…even in a large scope. But, if 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 by an observer in the southern hemisphere. When it comes to M74, this is the very best time of year to try with a smaller scope!

Sunday, November 23, 2008 – Tonight in 1885, the very first photograph of a meteor shower was taken. Also, the 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; it successfully tested 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 the orientation of the satellite’s spin. Coincidentally, a similar mission – Meteosat 1 – became the first satellite put into orbit by the European Space Agency, in 1977 on this day. Where is all this leading? Why not try observing satellites on your own? Thanks to wonderful online tools from NASA you can be alerted by e-mail whenever a bright satellite makes a pass over your specific area – or you can use other available tools to predict passes. It’s fun and doesn’t require any special equipment!

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

While you might find this little, sparkling, double handful of stars of little interest – think twice before you hop on. While DoDz studies are far more scattered and less populous that most galactic clusters, it doesn’t make them less interesting. What you are looking at are basically the fossils of a once active and more concentrated region of stars. As the cluster itself has matured, the lower mass members have been stripped away and have gone off to join 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!

For now? Ask for the Moon… But keep on reaching for the stars!

This week’s awesome images are: NGC 281, NGC 185 and NGC 147 – Credit: Palomar Observatory, courtesy of Caltech, M74 by R. Jay Gabany (for full image), and DoDz 1 – Credit: Palomar Observatory, courtesy of Caltech. Thank you so much!

Posted on by Tammy Plotner

Lepus

Lepus

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Created as one of Ptolemy’s original 48 constellations and positioned just south of the celestial equator, Lepus has endured the test of time to become one of the 88 modern constellation recognized by the IAU. Spanning 290 square degrees of sky, it ranks fifty-first in size and contains only 2 bright stars, yet has 8 stars in its major asterism. Within the confines of Lepus you will also find 20 stars with Bayer/Flamsteed designations. It is bordered by the constellations of Orion, Monoceros, Canis Major, Columba, Caelum and Eridanus. Lepus is visible to all observers at latitudes between +63° and ?90° and is best seen at culmination during the month of January.

In mythology, or perhaps more correctly story and legend, Lepus represents the hare at Orion the Hunter’s feet. It is believed the winged messenger god, Hermes honored the hare for its speed, giving it a place amongst the stars. It is also believed that Canis Major, Orion’s dog, forever pursues Lepus across the sky. The Egyptians saw this constellation as associated with Osiris and fertility… Of course, there is no more fertile creature than a rabbit!

Let’s start our binocular tour of Lepus with Alpha Leporis – the “a” symbol on our map. Its name is Arneb and it literally means “hare” in Arabic. Arneb is an older, dying star that may have already passed through a supergiant phase and is now contracting and heating up in the latter phases of stellar evolution, or perhaps is still expanding into the supergiant phase. With a mass of likely less than 10 times that of the Sun, it will likely end its life as a hot white dwarf, although if it is at the heavier end of its estimated mass it may end in a spectacular stellar explosion known as a supernova. Positioned about 1300 light years from Earth, Arneb may be dying… But it still has a few years of light left for you to enjoy!

Stay with binoculars and head south for Beta Leporis – the “B” symbol on our map. Beta’s proper name is Nihal – the “drinking camel”. Somewhat similar to our Sun, this unusual 159 light year distant dwarf star outshines Sol by 165 times. Why? Probably because it’s 16 times larger. Inside it has a rapidly evolving helium core and in less than a million years it will brighten as it begins to fuse its internal helium into carbon. Now take a look in a telescope. That’s right, Nihal is a binary star. About 2.5 seconds of arc away you’ll find a companion star that’s sometimes as bright as stellar magnitude 7 and sometimes as dim as 11. So what’s going on here? Chances are the companion star is an eclipsing double, much like an Algol-type. What’s more, the primary star – Nihal A – is also a bright X-ray source, which means it has strong stellar magnetic properties. According to research, it has a high content of yttrium and the rare earths praseodymium, neodymium, and samarium – chemicals that occurred because it began life just a little hotter than usual!

Now hop to Gamma Leporis – the “Y” shape on our chart. Gamma is a multiple star system which is about 29 light-years from Earth and consists of 2 or possibly 3 stars. What’s so cool about another multiple system? This one is on the move! Gamma is part of the Sirius Moving Group Of Stars. These stars are all about the same distance away and part of a larger collective of stars known as the Ursa Major Moving Group. Based upon its stellar characteristics and distance from Earth, Gamma Leporis, a main-sequence white-yellow dwarf star, is considered a high-priority target for NASA’s Terrestrial Planet Finder mission as well!

Point your binoculars or telescope at R Leporis – better known as “Hind’s Crimson Star”. Very few places in the sky will you find such ruby beauty! This well-known variable star is right on the border of Eridanus, but since the border doesn’t show on the sky, simply use bright Rigel to help you locate it. Named after famous British astronomer J.R. Hind, who observed it in 1845, you’ll find the most excellent carbon star varies from around magnitude 5 to 12 in about 427 to 432 days. In other words, you basically observe it from one year to the next! Hind’s Crimson star is the most beautiful when it is a minima, displaying an incredible smoky red color, which turns almost garnet as it brightens the following year. Enjoy this annual favorite!

Now keep those binoculars and telescopes handy as we drop a little less than four degrees south/southwest (a binocular field) of Beta and go for Messier 79 (RA 05:24.5 Dec -24:33). This 7th magnitude globular cluster was originally discovered by Pierre Mechain and later added to the Messier Catalog. Located about 40,000 light years from our solar system, the huge ball of stars spread across 118 light years of space an incorporates tens of thousands of distant suns. What’s unusual about it? Chances are, M79 is an import to our Milky Way Galaxy. From what we can tell through recent studies, this globular cluster may have actually belonged the the Canis Major dwarf galaxy at one time and became part of our galaxy through a galaxy collision! For double star fans, look another half degree southwest where you’ll see fifth magnitude ADS 3954 and its seventh magnitude companion. A nice same field bonus!

Sources: SEDS, Wikipedia
Chart Courtesy of Your Sky.

Posted on by Tammy Plotner

Leo Minor

Leo Minor

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Leo Minor is a very small and dim constellation which was created by Johannes Hevelius in 1687 and later recognized as one of the 88 modern constellations. While Leo Minor did not belong to any older star catalogs such as those drawn up by Ptolemy in the 2nd century AD, this set of stars became part of the Firmamentum Sobiescianum, a 56 sheet atlas created by master astronomer Hevelius in an attempt to update star catalogs using what (was then) considered modern equipment. Leo Minor was one of seven new constellations and endured to become officially recognized by the International Astronomical Union. It possesses no bright stars and has only 2 main stars in its asterism, yet there are 34 Bayer/Flamsteed designated stars within Leo Minor’s confines. It spans 232 square degrees of sky and is bordered by the constellations of Ursa Major, Lynx, Cancer and Leo. Leo Minor is visible to all observers at latitudes between +90° and ?45° and is best seen at culmination during the month of April.

Since Leo Minor, the “Little Lion” is consider a new constellation, it has no ancient mythology associated with it. As you may have noticed by looking at the chart, it curiously has no Alpha star. When it came to making charts, Hevelius was great – but he didn’t label stars. It wasn’t until the 19th-century when English astronomer Francis Baily had a go at Leo Minor that he assigned the stars with their Greek letters and he simply overlooked the Alpha designation! Leo Minor is just another example of how constellation names and figures can sometimes repeat themselves, like Ursa Major and Minor, Canis Major and Minor, Pegasus and Equuleus… Hydra and Hydrus. Half the challenge to this constellation is simply finding it!

Break out your binoculars and let’s have a look at Beta Leonis Minoris – the “B” shape on our map.. This is a very rapid binary star – not in terms of movement through space – but in orbit of its companion star. Believe it or not, the 6th magnitude companion completes a full orbit in less than 40 years. That’s just a little bit slower than Saturn takes to orbit our Sun and over twice as fast at it takes Neptune!

Now head east for 46 Beta Leonis Minoris. By all rights, this should have been the Alpha star and it’s the only Bayer/Flamsteed numbered stellar designation to have a proper name – Praecipua. As stars go? Well, Praecipua is actually pretty ordinary. Just another orange giant star hanging out in space around 98 light years from Earth. It is happily radiating away about 32 times brighter than our Sun and it is around 9 times bigger. One of the coolest things about this star is just how well we know it! According to Jim Kaler’s excellent information; “Recent accurate measures of angular diameter by the Navy Interferometer show it to be 0.00254 seconds of arc across (the separation of car headlights seen from a distance of 80,000 kilometers, 20 percent of the way to the Moon), which gives it a physical diameter 8.2 times that of the Sun, the agreement with the previously calculated diameter showing that we know the size, temperature, luminosity, and distance very well.”

Now, get out your telescope and let’s go on a galaxy hunt. Our first target is NGC 3486 (RA 11:00.4 Dec +28:58). At magnitude 10, this barred spiral galaxy discovered by Sir William Herschel is around 33 million light years away and it has attitude. Even in a small telescope, observers will note a bright, sharp nucleus and larger instruments will reveal a strong central bar and patchy structure that is the signature of a Seyfert galaxy.

Next up is a large telescope challenge – NGC 3344 (RA 10:43.31 Dec +24:55). Located much closer to the Milky Way Galaxy at 25 million light years in distance, this 13th magnitude grand design spiral galaxy is a face-on presentation, and only about half the size of our own galactic home. Like our preceding observation, it, too, has a central bar – but don’t be fooled by the foreground stars! According to studies done by Verdes-Montenegro (et al), the bar is exponential and dominates the central parts, while the bulge component is small. This makes this faint customer belong to the classification of a “ringed galaxy”.

Sources: SEDS, Wikipedia
Chart Courtesy of Your Sky.

Posted on by Tammy Plotner

Leo

Leo

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Positioned directly on the ecliptic plane, Leo is a constellation of the zodiac preceded by Cancer to the west and followed by Virgo to the east. It is an ancient constellation, originally charted by Ptolemy and recognized by the International Astronomical Union as one of the 88 modern constellations. Leo spans 947 square degrees of sky and is the twelfth largest of all. It contains 3 bright stars and around 15 stars in its asterism, with 92 Bayer/Flamsteed designated stars within its confines. It is bordered by the constellations of Ursa Major, Leo Minor, Lynx, Cancer, Hydra, Sextans, Crater, Virgo and Coma Berenices. Leo is visible to all observers located at latitudes between +90° and ?65° and is best seen at culmination during the month of April.

There are five annual meteor showers associated with constellation Leo. The first is the Delta Leonid meteor stream which begins becoming active between February 5 through March 19 every year. The activity peaks in late February with no exact date, and the maximum amount of activity averages around 5 meteor per hour. The next date is April 17 and the Sigma Leonid meteor shower. Look for this rare occurrence to happen near the Leo/Virgo border. It is a very weak shower and activity rates no higher than 1 to 2 meteors per hour. The next is the most dependable shower of all – the November Leonids. The peak date is November 17th, but activity occurs around 2 days on either side of the date. The radiant is near Regulus and this is the most spectacular of modern showers. The year 1966 saw 500,000 per hour a rate of up 140 per second! Just a few years ago, in 2005 the rates were equally impressive. Why? Comet Temple-Tuttle is the answer. Whenever it nears perihelion, it adds fresh material to the stream and gives us a spectacular show. On the average, you can expect around 20 per hour between 33 year shows, but they are the fastest known at 71 kps. The last is the Leo Minorids which peak on or about December 14. This meteor shower was discovered by amateurs in 1971 and hasn’t really been confirmed yet, but do look for around 10 faint meteors per hour.

In Greek mythology, Leo was identified as the Nemean Lion, which may have been the source of the “tail” of the lion that killed Hercules during one of his twelve labors. While many constellations are difficult to visualize, Leo’s backwards question-mark is relatively easily to picture as a majestic lion set in stars. One of the reasons for its placement in the zodiac is possibly due to the fact that lions left their place in the desert for the banks of the Nile when the Sun was positioned in these stars. It is also possible that the Nile’s rise at this time and the lion’s migration is also the reason for the Sphinx to appear as it does – a leonine figure. The Persians called it Ser or Shir; the Turks, Artan; the Syrians, Aryo; the Jewish, Arye; the Indians, “Sher”; and the Babylonians, Aru — all meaning a lion. Early Hindu astronomers recognized it by regal names, as did other cultures. All befitting of the “King of Beasts”!

Let’s begin our tour by taking a look at the brightest star – Alpha Leonis – the “a” symbol on our map. Its name is Regulus and it is one hot customer when it comes to spin rate. Revolving completely on its axis in a little less than 16 hours, oblate Regulus would fly apart if it were moving any faster. Ranking as the twenty-first brightest star in the night sky, Alpha Leonis is a helium type star about 5 times larger and 160 times brighter than our own Sun. Speeding away from us at 3.7 kilometers per second, Regulus isn’t alone, either. The “Little King” is a multiple star system composed of a hot, bright, bluish-white star with a pair of small, faint companions easily seen in small telescopes. The companion is itself a double at around magnitude 13 and is a dwarf of an uncertain type. There is also a 13th magnitude fourth star in this grouping, but it is believed that it is not associated with Regulus since the “Little King” is moving toward it and will be about 14″ away in 785 years. Not bad for a star that’s been reigning the skies for around for a few million years!

Let’s fade east now, and take a look at Beta Leonis – the “B” symbol on our map. Its name is Denebola which means the “Lion’s tail” in Arabic. Located about 36 light years from Earth, this white class A dwarf star is more luminous than the Sun, emitting 12 times the solar energy and a Delta-Scuti type variable star. While that in itself isn’t particularly rare, what makes Denebola unusual is that it belongs to the Vega-class stars – ones that have a shroud of infra-red emitting dust around them. This could mean a possibility of planet forming capabilities! In binoculars, look for an optical double star companion to Beta. It’s not gravitationally, or physically related, but it’s a pleasing pairing.

Now, return to Regulus and hop up for Eta Leonis, the “n” symbol on our map. Eta is very special because of its huge distance – about 2100 light years from our solar system – and that’s only a guess. It is a supergiant star, and one that is losing its stellar mass at a huge rate. Compared to Sol, Eta loses 100,000 times more mass each year! Because of its position near the ecliptic plane, Eta is also frequently occulted by the Moon. Thanks to alert observers, that’s how we learned that Eta is also a very close binary star, too – with a companion only about 40% dimmer than the primary. Some time over the next 17 million years, the pair of red supergiant stars will probably merge to become a pair of massive white dwarf stars… or they may just blow up. Only time will tell…

Hop north for Gamma Leonis – the “Y” symbol on our map. Its name is Algeiba and it is a very fine double visual star for binoculars and and true binary star small telescopes. Just take a look at this magnificent orange red and and yellow pair under magnification and you’ll return again and again. The brighter primary star is a giant K type and orbiting out about four times the distance of Pluto is its giant G type companion. Further north you’ll find another excellent visual double star for binoculars – Zeta Leonis. It’s name is Aldhafera and this stellar spectral class F star is about 260 light years away.

Are you ready to try your hand at locating a pair of galaxies with binoculars? Then let’s try the “Leo Trio” – M65, M66 and NGC 3623. Return towards Beta and look for the triangular area that marks the asterism of Leo’s “hips”. If the night is suitable for binocular galaxy hunting, you will clearly see fifth magnitude Iota Leonis south of Theta. Aim your binoculars between them. Depending on the field of view size of your binoculars, a trio of galaxies will be visible in about one third to one fourth of the area you see. Don’t expect them to walk right out, but don’t sell your binoculars short, either. The M65 and M66 pair have higher surface brightness and sufficient size to be noticed as two opposing faint smudges. NGC 3623 is spot on the same magnitude, but is edge on in presentation instead of face-on. This makes it a lot harder to spot, but chances are very good your averted vision will pick it up while studying the M65/66 pair. The “Leo Trio” makes for a fine challenge!

Now let’s begin working with larger binoculars and small telescopes as we head for M96 galaxy group (RA 10h 46m 45.7s Dec +11 49′ 12″). Messier 96 is the brightest spiral galaxy within the M96 Group which includes Messier 95 and Messier 105 as well as at least nine other galaxies. Located about 38 million light years away, this group of galaxies with the Hubble Space Telescope and 8 Delta Cephei variable stars were found to help determine each individual galaxy’s distance. While you can’t expect to see each member in small optics, larger telescopes can hope to find elliptical galaxies NGC 3489 (11:00.3 +13:54), NGC 3412 (10:50.9 +13:25), NGC 3384 (10:48.3 +12:38) and NGC 3377 (10:47.7 +13:59), as well as barred spiral galaxy NGC 3299 (10:36.4 +12:42),

For an awesome spiral galaxy in a small telescope, don’t overlook NGC 2903 (RA 9:32.2 Dec +21:30). At a bright magnitude 9, you can often see this particular galaxy in binoculars from a dark sky site as well. Discovered by William Herschel in 1784, this beauty is often considered a missing Messier because it just so bright and conspicuous. As a matter of fact, the comet of 1760 passed it on a night Messier was watching and he didn’t even see it! For larger telescopes, look for NGC 2905 – a bright knot which is actually a star forming region in the galaxy itself with its own Herschel designation.

Before we leave, you must stop by NGC 3521 (RA 11:05.8 Dec -00:02). This 35 million light year distant spiral galaxy is often overlooked for no apparent reason – but it shouldn’t be. At a very respectable magnitude 9, you can often find this elongated gem with the bright nucleus in larger binoculars from a dark sky site and you can easily study spiral galaxy structure with a larger telescope. Look for an inclined view with patchiness in the structure that indicates great star forming regions at work. Its stellar counter rotation is being studied because it has a bar structure that we are seeing “end on”!

This doesn’t even begin to scratch the surface of what you can find on Leo’s hide. Be sure to get yourself a good star chart or sky atlas and go lion taming!

Sources: SEDS, Wikipedia
Chart Courtesy of Your Sky.

Posted on by Tammy Plotner

Lacerta

Lacerta

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The constellation of Lacerta is unusual, because it did not belong orignally to those created by Ptolemy – but to the works of Johannes Hevelius. Lacerta was included in Firmamentum Sobiescianum, a 56 page atlas created by Hevelius, which outlined seven new constellations which survived time – and many which did not. Positioned north of the ecliptic plane, it spans 201 square degrees of sky and contains 5 main stars in its asterism and 17 Bayer/Flamsteed designated stars within its boundaries. Lacerta is bordered by the constellations of Andromeda, Cassiopeia, Cepheus, Cygnus and Pegasus. It is visible to all observers at latitudes between +90° and ?90° and is best seen at culmination during the month of December.

Since Lacerta is considered a “modern” constellation, there is no mythology associated with it – although the stellar pattern was very visible to the ancient Greeks and Romans. At the time, Native American culture was highly regarded and the Chusmash of the California region referred to this area of the sky as the “Lizard”. Perhaps Hevelius honored their many stories and their culture by adopting the Latin term for lizard – Lacerta – and placing it upon this constellation.

Although Lacerta contains no bright stars, once you pick out its dim lightning bolt pattern of stars you’re well on the way to exploring with binoculars or a telescope. A sure way to help locate it is to wait for a dark night and scan the sky between Cassiopeia and Cygnus. When you’re ready, let’s take a look at Alpha Lacertae – the “a” symbol on our map. While it is just a rather ordinary A-class star residing about 102 light years away from our solar system, Alpha is about twice the size of our Sun and shines about 27 more brightly. Take a look through a telescope and you will see that Alpha appears to have a companion, but it is only an optical double star. The 11.8 magnitude line of sight interloper is really almost 2600 more light years away!

Now hop to Beta Lacertae – the “B” symbol on our map. Located about 170 light years from Earth, Beta is a giant yellow star, similar in some ways to our own Sun, but far more massive. If you’re seeing a field of stars to the west/southwest of Beta in binoculars, you’d be correct. Positioned about 2.6 degrees away from Beta is loose open cluster NGC 7243, also known as Best 59 or Caldwell 16. It contains about 40 stars and is spread out over a very large area which makes it a nice binocular object. If you’ve got the magnification power of a telescope on it, be sure to check out the brightest star in the cluster. Its name is Struve 2890 and it’s a great double star! For a telescope viewing challenge, look about 2 degrees west/northwest of Beta for IC 1434 – another open cluster. At magnitude 10, the small compressed beauty is meant for larger optics!

For another great rich field telescope treat, aim your sights towards NGC 7209 (RA: 22h 05m 12.0s Dec.:+46 29’ 59”). At a comfortably bright magnitude 7.7, this galactic star cluster is well compressed and very rich in stars. Also known as Collinder 444 and Melotte 238, this stellar beauty has been studied photometrically for reddening and metallicity, as well as the presence of suspected binary stars. Viewable in binoculars as a dim, hazy patch and well resolved in the telescope.

For binary star fans, have a look at 8 Lacerta (RA 22h 35m 52.28s Dec.: +39d 38’ 03.6”). Here you’ll find a beautiful multiple star system that’s also on the Astronomical League 100 list. In the telescope eyepiece, look for a 5.7 magnitude primary star accompanied by a 6.5 secondary star separated by about 22″. Further away you’ll find the 7.2 magnitude C star separated by about 82″. It’s very worthy of your time and attention!

Source: Wikipedia
Chart Courtesy of Your Sky.

Posted on by Tammy Plotner

Weekend SkyWatcher’s Forecast – November 14-16, 2008

Greetings, fellow SkyWatchers! Are you ready for one terrific weekend? Although the Moon will interfere, one of the year’s best meteor showers is about to happen – the Leonids. Will it be the super-storm that produced thousands of meteors as it did a few years ago? Don’t hold your breath – but chances are very good you’ll spot more than one meteor for just spending a little bit of time observing. For those who enjoy using small telescopes and binoculars, it’s time to rock with the Queen as we take a look around in Cassiopeia, too. Are you ready to rock the night? Then let’s go….

Friday, November 14, 2008 – 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 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 day in 1971, Mariner 9 became the first space probe to orbit Mars. Can you still spot the faint Mars at sunset?

While Cassiopeia is in prime position for most northern observers, let’s head that way tonight for some fun studies. Starting with Delta, let’s hop to the northeast corner of our “flattened W” and identify 520 light-year distant Epsilon. For larger telescopes only, it will be a challenge to find the 12″ diameter, magnitude 13.5, planetary nebula known as I.1747 in the same field as magnitude 3.3 Epsilon!

Using both Delta and Epsilon as our “guide stars,” let’s draw an imaginary line between the pair extending from southwest to northeast, continuing it the same distance until you stop at visible Iota (RA 02 29 03 Dec +67 24 08). Now go to the eyepiece… As a quadruple system, Iota will require a telescope and a night of steady seeing to split its three visible components. Approximately 160 light-years away, this challenging system will show little or no color to smaller telescopes, but to large aperture, the primary may appear slightly yellow and the companion stars a faint blue. At high magnification, the 8.2 magnitude C star will easily break away from the 4.5 primary, 7.2″ to the east-southeast. But look closely at that primary: hugging in very close (2.3″) to the west-southwest and looking like a bump on its side is the B star!

Dropping back to the lowest of powers, place Iota at the southwest edge of the eyepiece. It’s time to study two incredibly interesting stars that should appear in the same field of view to the northeast. When both of these stars are at their maximum, they are easily the brightest stars in the field. Their names are SU (southernmost – right) and RZ (northernmost – left) Cassiopeiae, and each is unique! SU (RA 02 51 58 Dec +68 53 18) is a pulsing Cepheid variable located about 1000 light-years away, and will show a distinctive red coloration. RZ (RA 02 48 55 Dec +69 38 03) is a rapidly eclipsing binary which can change from magnitude 6.4 to magnitude 7.8 in less than two hours. Wow!

Saturday, November 15, 2008 – On this day in 1990, Phil Harrington’s first book Touring the Universe through Binoculars was released, making the author a household name in the astronomy world. Since that time, Phil has published seven additional books, given countless lectures, is a contributing author to well-known astronomy periodicals, and presents technical training at Brookhaven National Laboratory. His achievements are many, and we salute you!

Above all, today we mark a very special birthday: on this day in 1738 my personal hero William Herschel was born. Among this British astronomer 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 writing catalogs whose information we still use today. Just look at how many we’ve logged this year! Tonight let’s look toward Cassiopeia as we remember this great astronomer…

Although Herschel discovered many of the famous “400” objects in Cassiopeia just two days after his birthday in 1787, we only have a short time before the Moon rises, so let’s set our sights on the area between Delta and Epsilon and have a look at three of them: NGC 654, NGC 663 and NGC 659.

At magnitude 6.5, NGC 654 (RA 01 44 00 Dec +61 53 00) is achievable in 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 production of low mass stars after the larger 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.

Now shift your attention to NGC 663 (RA 01 46 12 Dec +61 14 00). At magnitude 7, it is also viewable as a faint glow in binoculars – but is best in a telescope. With an age of about nine million years, this cluster contains the largest concentration of Be-type stars known: such stars show strong emission lines in hydrogen. While this might be considered “normal” for a B-type star, the mystery behind Be-types is that their emissions can simply end at any time – only to resume later. This could be in a matter of days, or it could be decades – but these odd stars may very well be victims of rapid rotation, high magnetic activity (similar to flares), or even interactions with a companion.

Time to head toward the faintest of the three – NGC 659 (RA 01 44 24 Dec +60 40 00). At magnitude 8, it is still within the reach of larger binoculars and will be fully resolved with a mid-sized telescope. Studied as recently as 2001, this looser collection contains seven newly discovered variables – three of which are Be stars. But, give credit where credit is due! For as avid as Sir William was about observing, he had an equally avid observing partner: his sister Caroline. This time it was her call, as she is credited with the discovery of this particular open cluster – four years before her brother added it to his list in 1787!

Sunday, November 16, 2008 – Today in 1974, there was a party at Arecibo, Puerto Rico, as the new surface of the giant 1000-foot radio telescope was dedicated. At this time, a quick radio message was released in the direction of the globular cluster M13.

Tonight let’s take advantage of early dark and venture further into Cassiopeia. Returning to Gamma, we will move toward the southeast and identify Delta. Also known as Ruchbah, this long-term and very slightly variable star is about 45 light-years away, but we are going to use it as our marker as we head just one degree northeast and discover M103 (RA 01 33 24 Dec +60 39 00). As the last object in the original Messier catalog, M103 (NGC 581) was actually credited to Méchain in 1781. Easily spotted in binoculars and small scopes, this rich open cluster is around magnitude 7, making it a prime study object. About 8000 light-years away and spanning approximately 15 light-years, M103 offers up superb stars in a variety of magnitudes and colors, with a notable red in the south and a pleasing yellow and blue double to the northwest.

Keep watch for shooting stars tonight, because the annual Leonid meteor shower is underway. For those of you seeking a definitive date and time, it isn’t always possible. 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 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.

So if you didn’t stay up late, then get up early the next morning to catch the Leonids. 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, but what about this year? On November 8, 2005 the Earth passed through an ancient stream shed in 1001. Predictions ran high for viewers in Asia, but the actual event resulted in a dud. There is no doubt that we crossed through that stream, but its probability of dissipation was impossible to calculate. Debris trails left by the comet in subsequent years look promising, but we simply don’t know.

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. With the Moon blocking the way, it will be difficult this year, but wait until the radiant constellation of Leo rises and the chances are good of spotting one of the offspring of periodic comet Tempel-Tuttle. Remember to dress warmly and provide for your viewing comfort.

Enjoy your weekend and remember… Ask for the Moon, but keep on reaching for the stars!

This week’s awesome images are: Iota, SU and RZ Cassiopeiae – Credit: Palomar Observatory, courtesy of Caltech, Sir William Herschel (widely used public image), NGC 654, NGC 653, NGC 659 and M103 – Credit: Palomar Observatory, courtesy of Caltech and Leonid Meteor Shower – Credit: NASA. We thank you so much!