Posted on by Tammy Plotner

Portrait Of NGC 5189: New Light On An Old Planetary Nebula

Composite Image of NGC 5189 Courtesy of Robert Gendler

Stretching across three light years of space and located about 3,000 light years away in the direction of the constellation of Musca, an incredible and rather understudied planetary nebula awaits a new hand to bring out new light. While most planetary nebula have a rather normal, bloated star look, NGC 5189 shows an extraordinary amount of loops and curls not normally seen in objects of its type. Just what is going on here?

This incredibly detailed image comes from the one and only Robert Gendler and was assembled from three separate data sources. The detail for the nebula is from Hubble Space Telescope data, the background starfield from the Gemini Observatory/AURA and the color data from his own equipment. Here we see fanciful gas clouds with thick clumps decorating them. Intense radiation and gas streams from the central dying star in waves, fashioning out hollows and caves in the enveloping clouds. While these clumps in the clouds may appear as wispy details, each serves as a reminder of just how vast space can be… for each an every one of them is about the same size as our Solar System.

“The complex morphology of this PN is puzzling and has not been studied in detailed so far. Our investigation reveals the presence of a new dense and cold infrared torus (alongside the optical one) which probably generated one of the two optically seen bipolar outflows and which might be responsible for the twisted appearance of the optical torus via an interaction process.” says L. Sabin (et al). ” The high-resolution MES-AAT spectra clearly show the presence of filamentary and knotty structures as well as three expanding bubbles. Our findings therefore suggest that NGC 5189 is a quadrupolar nebula with multiple sets of symmetrical condensations in which the interaction of outflows has determined its complex morphology.”

And just as incredibly large as some things can be – others can be as small. At the heart of NGC 5189 shines the tiny light of its central star… no bigger than Earth. It wobbles its way through time, rotating rapidly and spewing material into space like a runaway fire hydrant. Astronomers speculate there might be a binary star hidden inside, since usually planetary nebulae of this type have them. However, only one star has been found at the nebula’s center and it might be one very big, very bad wolf.

“Around 15% are known or suspected binaries, while the remaining 18% are non-emission line nuclei which require further study. Selecting for LIS (low ionization structures) therefore will give a mix of mostly binary and emission line nuclei which will require further observations to separate.” explains B. Miszalski (et al). “Almost all the [WR] CSPN in the sample belong to the hot [WO] type that have more extreme and chaotic LIS covering their entire nebulae, presumably due to turbulence from the strong [WR] winds disrupting pre-existing LIS.”

Just why is this celestial tapestry so complicated and complex? The answer isn’t a simple one – it’s one that has many plausible theories. We know that when a star similar to the Sun expends its fuel, it will begin to shed its outer layers… layers which normally take on very basic shape. These “normal” shapes are usually a sphere, sometimes a double lobe and at times it can be a ring or helix. However, NGC 5189 just doesn’t follow rules. Over time, researchers have speculated it has given off different outlfows at different stages – one prominent as a very visible torus situated around mid-point in the structure – consistent with the theory of a binary star system with a precessing symmetry axis. Still, there is clearly more research needed.

“Our preliminary results of a comparative spectroscopic study of these two objects shows that the chemical composition of the two nebulae is completely different, even though their morphology is most probably quite similar.” says VF Polcaro (et al). ” In addition, the PN appears much more chemically homogeneous. These features are clearly associated with the evolutionary paths of the stars.”

“The striking broad emission line spectroscopic appearance of Wolf-Rayet (WR) stars has long defied analysis, due to the extreme physical conditions within their line and continuum forming regions.” explains Paul Crowther. “Theoretical and observational evidence that WR winds depend on metallicity is presented, with implications for evolutionary models, ionizing fluxes, and the role of WR stars within the context of core-collapse supernovae and long-duration gamma ray bursts.”

Is NGC 5189 the handiwork of a binary star? Or is it the product of an intensely hot Wolf-Rayet? Like the proverbial Tootsie Pop equation… the world may never know.

Many thanks to Robert Gendler for sharing this incredible image with us.

Posted on by Tammy Plotner

Supernovae Seed Universe With Cosmic Rays

In a wave of media releases, the latest studies performed by NASA’s Fermi Gamma-ray Space Telescope are lighting up the world of particle astrophysics with the news of how supernovae could be the progenitor of cosmic rays. These subatomic particles are mainly protons, cruising along through space at nearly the speed of light. The rest are electrons and atomic nuclei. When they meet up with a magnetic field, their paths change like a bumper car in an amusement park – but there’s nothing amusing about not knowing their origins. Now, four years of hard work done by scientists at the Kavli Institute for Particle Astrophysics and Cosmology at the Department of Energy’s (DOE) SLAC National Accelerator Laboratory has paid off. There is evidence of how cosmic rays are born.

“The energies of these protons are far beyond what the most powerful particle colliders on Earth can produce,” said Stefan Funk, astrophysicist with the Kavli Institute and Stanford University, who led the analysis. “In the last century we’ve learned a lot about cosmic rays as they arrive here. We’ve even had strong suspicions about the source of their acceleration, but we haven’t had unambiguous evidence to back them up until recently.”

Until now, scientists weren’t clear on some particulars – such as what atomic particles could be responsible for the emissions from interstellar gas. To aid their research, they took a very close look at a pair of gamma ray emitting supernova remnants – known as IC 443 and W44. Why the discrepancy? In this case gamma rays share similar energies with cosmic ray protons and electrons. To set them apart, researchers have uncovered the neutral pion, the product of cosmic ray protons impacting normal protons. When this happens, the pion rapidly decays into a set of gamma rays, leaving a signature decline – one which provides proof in the form of protons. Created in a process known as Fermi Acceleration, the protons remain captive in the rapidly moving shock front of the supernova and aren’t affected by magnetic fields. Thanks to this property, the astronomers were able to trace them back directly to their source.

“The discovery is the smoking gun that these two supernova remnants are producing accelerated protons,” said lead researcher Stefan Funk, an astrophysicist with the Kavli Institute for Particle Astrophysics and Cosmology at Stanford University in California. “Now we can work to better understand how they manage this feat and determine if the process is common to all remnants where we see gamma-ray emission.”

Are they little speedsters? You betcha. Every time the particle passes across the shock front, it gains about 1% more speed – eventually enough to break free as cosmic ray. “Astronauts have documented that they actually see flashes of light associated with cosmic rays,” Funk noted. “It’s one of the reasons I admire their bravery – the environment out there is really quite tough.” The next step in this research, Funk added, is to understand the exact details of the acceleration mechanism and also the maximum energies to which supernova remnants can accelerate protons.

However, the studies don’t end there. More new evidence of supernovae remnants acting like particle accelerators emerged during careful observational analysis by the Serbian astronomer Sladjana Nikolic (Max Planck Institute for Astronomy). They took a look at the composition of the light. Nikolic explains: “This is the first time we were able to take a detailed look at the microphysics in and around the shock region. We found evidence for a precursor region directly in front of the shock, which is thought to be a prerequisite of cosmic ray production. Also, the precursor region is being heated in just the way one would expect if there were protons carrying away energy from the region directly behind the shock.”

Nikolic and her colleagues employed the spectrograph VIMOS at the European Southern Observatory’s Very Large Telescope in Chile to observe and document a short section of the shock front of the supernova SN 1006. This new technique is known as integral field spectroscopy – a first-time process which allows astronomers to thoroughly examine the composition of the light from the supernova remnant. Kevin Heng of the University of Bern, one of the supervisors of Nikolic’s doctoral work, says: “We are particularly proud of the fact that we managed to use integral field spectroscopy in a rather unorthodox way, since it is usually used for the study of high-redshift galaxies. In doing so, we achieved a level of precision that far exceeds all previous studies.”

It really is an intriguing time to be taking closer looks at supernovae remnants – especially in respect to cosmic rays. As Nikolic explains: “This was a pilot project. The emissions we observed from the supernova remnant are very, very faint compared to the usual target objects for this type of instrument. Now that we know what’s possible, it’s really exciting to think about follow-up projects.” Glenn van de Ven of the Max Planck Institute for Astronomy, Nikolic’s other co-supervisor and an expert in integral field spectroscopy, adds: “This kind of novel observational approach could well be the key to solving the puzzle of how cosmic rays are produced in supernova remnants.”

Kavli Institute Director Roger Blandford, who participated in the Fermi analysis, said, “It’s fitting that such a clear demonstration showing supernova remnants accelerate cosmic rays came as we celebrated the 100th anniversary of their discovery. It brings home how quickly our capabilities for discovery are advancing.”

Original Story Sources and Further Reading: Novel approach in hunt for cosmic particle accelerator, NASA’s Fermi Proves Supernova Remnants Produce Cosmic Rays, and Proof: Cosmic Rays Come from Exploding Stars.

Posted on by Tammy Plotner

New Research Sheds Light On Black Hole Growth

The black hole that has grown the most can be found in the Sombrero galaxy . The researchers estimate that this black hole has been swallowing the equivalent of one Sun every twenty years and is now over 500 million times as heavy as the Sun. ESO Public Image Release

In a new study led by University of Central Lancashire astronomer Dr. Victor Debattista, researchers are looking into the mystery of how black holes grow and evolve. For many years, astronomers surmised black holes took on mass when their host galaxies merged, but now new modeling techniques show that black holes in spiral galaxies are forced to take on mass.

“Recent Hubble Space Telescope (HST) observations have revealed that a majority of active galactic nuclei (AGN) are resident in isolated disk galaxies, contrary to the usual expectation that AGN are triggered by mergers.” says Debattista. “Here we develop a new test of the cosmic evolution of supermassive black holes (SMBHs) in disk galaxies by considering the local population of SMBHs. We show that substantial SMBH growth in spiral galaxies is required as disks assemble.”

Weighing in a range of one million to one billion times that of the Sun, the black holes located at the core of most galaxies would appear to be gaining at much quicker rates than expected. These are not just exceptions – more like rules. Even the Milky Way’s quiescent black hole might be gaining as much mass as the Sun every 3,000 years. Past observations have shown growth during collision events, when huge amounts of gas around the black hole become intensely hot and shine as an active galactic nucleus. This is a process which can be spotted as far back as the first formations in our Universe. However, these new simulations are giving insight into large scale growth without the need for violence.

“The X-ray-selected sample of moderate luminosity AGN consists of more than 50% disk galaxies, with ongoing mergers evident no more frequently than in nonactive galaxies.” explains the research team. “Some show that even heavily obscured quasars are hosted largely by disks, not by mergers. Studies of star-formation using Herschel find that the specific star formation rates of X-ray selected AGN hosts are no different from those of inactive galaxies, also indicating that AGN hosts are not undergoing fundamentally different behaviors”

These modeling techniques, combined with current observations done with the Hubble Space Telescope, give credence to the theory that black holes can gain significant mass even in “quiet” spiral galaxies. As a matter of fact, there is a strong possibility that AGNs present in some spiral galaxies may even outnumber galaxy mergers. To make this concept even more exciting, astronomers are anticipating an event later this year in our own galaxy – an event where a gas cloud near the Milky Way’s nucleus will encounter our own central black hole. According to predictions, our black hole may take on as much as 15 Earth masses in a period of 10 years from this cloud.

This concept of black hole growth isn’t entirely new, though. According to other research done with the Hubble Space Telescope and led by Dr. Stelios Kazantzidis of Ohio State University and Professor Frank C. van den Bosch of Yale University, they had previously pinpointed mass properties of black holes – making size predictions which utilized the speed of stars residing in the galaxies. In this instance, the team disproved previous assumptions that black holes were unable to grow while the host galaxy grew. Their comparison of spiral and elliptical galaxies “found there is no mismatch between how big their black holes are.” This means black holes would be gaining in mass – growing along at the same rate as the galaxy itself.

“These simulations show that it is no longer possible to argue that black holes in spiral galaxies do not grow efficiently. ” comments Debattista on this new research. ” Our simulations will allow us to refine our understanding of how black holes grew in different types of galaxies.”

Posted on by Tammy Plotner

Messier 106: Amateur and Professional Astronomers Join Together to Peer Into the Eyes of Creation

Traveling to distant galaxies may have interesting consequences. Credit: Hubble Release, Messier 106

Nearly four million light years away in the direction of the constellation of Canes Venatici, a visage of creation awaited to be revealed. Now, thanks to the teamwork of the astronomical image processors at the Space Telescope Science Institute in Baltimore, Maryland, and world-renowned astrophotographers Robert Gendler and Jay GaBany, we’re able to see combined Hubble Space Telescope data with ground-based telescope imaging. Let’s look deep into spiral galaxy, Messier 106.

This wasn’t an overnight imaging project. “A few months ago the Hubble Heritage Team contacted me and asked if I’d be interested in making a large format image of M106 from the available data on the Hubble Legacy Archive,” says Gendler. “I agreed and went to work downloading a large number of data sets from the HLA. I realized this would be a massive project. The image would be a mosaic of more than 30 panels and would incorporate both wideband and narrowband data sets.”

With the cooperation of Jay GaBany, they combined their own observations/images of this magnificent structure and compiled it with Hubble data – filling in areas where no data was available. The resulting image is a portrait of such depth and beauty that it’s almost like looking into the eyes of creation itself.

Be swept away…

If you’re drawn to the core of Messier 106, there’s good reason. It isn’t just an ordinary spiral galaxy, it’s one that has a peculiar jet flow which can be detected in radio and in H-alpha wavelengths. “Due to the special geometry of the galaxy, the jets emerge from the nuclear region through the galactic disk,” says Marita Krause (et al). “Also the distribution of molecular gas looks different from that in other spiral galaxies.” It is just this difference that makes NGC 4258 (M106) stand out a bit from the crowd and so worthy of further processing. According to new modeling techniques the “concentration of CO along the ridges is due to interaction of the rotating gas clouds with the jet’s magnetic field by ambipolar diffusion. This magnetic interaction is thought to increase the time the molecular clouds reside near the jet thus leading to the quasi-static CO ridge.”

Knowing those jets are present and the hunger to reveal them through imaging became the driving force for R. Jay GaBany. “Since the early 1960s, M106, also known as NGC 4258, has been known to exhibit an extra pair of arms, located between the spiral arms comprised of stars, dust and gas. But an explanation for their existence remained elusive until earlier in this decade,” says Jay. “My contribution to the image came from my 2010 image of M-106 that revealed the full extent of its amazing jets. My image include 22 hours of white light exposures through clear, red, blue and green filters plus and other 15 hours of imaging through a 6nm narrow band h-alpha filter.”

Messier 106 Courtesy of R. Jay GaBany
Messier 106 Courtesy of R. Jay GaBany

“Seen in the light emitted by hydrogen molecules when they become ionized, these arms display an artificial red hue to make them visible in the image I produced. The extra arms are now believed to be caused by high energy jets emanating from an active 40 million solar mass super-massive black hole menacing the galaxy’s center,” explains GaBany. “Because the jets are tilted at a low inclination they pierce the disk and surrounding halo of this galaxy. So, as the jets pass through regions of gas, they create an expanding cocoon of shock waves that heats the surrounding material causing it to release radiation in optical wavelengths. The curvature and fraying seen at their extremities represents previous trajectories of the jet due to past precession. Precession is a change in the orientation of the rotation axis of a spinning object. For example, the wobble of a spinning top.”

Yet, that’s not all. This low luminosity Seyfert II galaxy is also hosting a maser – its warped disk of water molecules discovered in 1994. Through radio observations, M106 became the first of its kind to show the exact location of the core of an AGN (active galactic nucleus). According to a study done by JR Herrnstein (et al): “NGC 4258 is an exceptional laboratory for the study of AGN accretion processes. The nuclear maser reveals details about the kinematics and structure of the accretion disk on subparsec scales and permits the determination of the central mass with great precision.”

And there is still more…

Deep inside lurks that known supermassive black hole – one that’s extremely active and produces bright microwave radiation. But, don’t stop there. Ordinarily a spiral galaxy has two arms, but M106 has double. These ethereal “extras” can be seen as faint ribbons of gas at optical wavelengths, but become solidified when viewed in x-ray and radio. Here the structure is formed in hot gas rather than stars. While this process was once a mystery to astronomers, new information suggests they may arise from the black hole activity, making them a unique artifact. What could cause it? These “extra arms” could be the result of the violent turbulence at the core – where gases are superheated and interact with their denser counterparts causing them to illuminate. At the perimeter of the galactic structure, the gases are more loose and the arching formation could be the product of the movement of jet activity.

“One goal I had early on was to feature the well known ‘anomalous arms’ of M106,” said Gendler. “This feature, peculiar to M106, is thought to arise from superheated gases, energized by accretion of matter into the galaxy’s massive black hole. The anomalous arms emit light in the visual spectrum around 656nm (hydrogen alpha) and I found a fair amount of hydrogen alpha data sets for the arms in the HLA.”

Gendler was responsible for all the image assembly and processing. “Assembling the image required over two months,” he said. “The quality of the data ranged from good to very poor. The central galaxy had sufficient color data but away from the center the Hubble data was incomplete and in some areas did not exist. I then decided to use ground based data from my own image and Jay GaBany’s image of M106 to fill in areas of missing or incomplete Hubble data. I also used ground based data to boost the signal of the outer areas of the galaxy as the Hubble data was sparse and of short exposure for the more remote areas of the galaxy.”

All in all, Messier 106 is a galaxy that deserves attention – attention and a loving touch given by two of the very best amateur astronomers and dedicated astrophotographers to be found.

Original News Source: HubbleSite Image Release.

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: December 3-9, 2012



NGC 457 Courtesy of Ken and Emilie Siarkiewicz/Adam Block/NOAO/AURA/NSF

Greetings, fellow SkyWatchers! With a whole lot less Moon present in the early evenings, it’s time to do some very different studies – from North to South! We’ll be having a look at planetary nebulae, globular clusters, galactic star clusters and some great galaxies, too! Need more? Then SH viewers can kick back and relax to a meteor shower, too! Whenever you’re ready, just meet me in the back yard…

Monday, December 3 – Today in 1971, the Soviet Mars 3 became the first spacecraft to make a soft landing on the red planet, and two years later on this same date the Pioneer 10 mission became the first spacecraft to fly by Jupiter. One year later on this same date? Pioneer 11 did the same thing!

Tonight let’s familiarize ourselves with the vague constellation of Fornax. Its three brightest stars form a shallow V just south of the Cetus/Eridanus border and span less than a handwidth of sky. Although it’s on the low side for northern observers, there is a wealth of sky objects in this area.

Try having a look at the easternmost star – 40-light-year distant Alpha. At magnitude 4, it is not easy, but what you’ll find there is quite beautiful. For binoculars, you’ll see a delightful cluster of stars around this long-term binary – but telescopes will enjoy it as a great golden double star! First measured by John Herschel in 1835, the distance between the pair has narrowed and widened over the last 172 years and it is suspected its orbital period may be 314 years. While the 7th magnitude secondary can be spotted with a small scope – watch out – because it may also be a variable which drops by as much as a full magnitude!

Tuesday, December 4 – Today in 1978, the Pioneer/Venus Orbiter became the first spacecraft to orbit Venus. And in 1996, the Mars Pathfinder mission was launched!

For larger telescopes, set sail for Beta Fornacis tonight and head 3 degrees southwest (RA 02 39 42.5 Dec -34 16 08.0) for a real curiosity – NGC 1049.

At magnitude 13, this globular cluster is a challenge for even large scopes – and with good reason. It isn’t in our galaxy. This globular cluster is a member of the Fornax Dwarf Galaxy – a one degree span that’s so large it was difficult to recognize as extra-galactic – or at least it was until the great Harlow Shapely figured it out! NGC 1049 was first discovered and cataloged by John Herschel in 1847, only to be reclassified as “Hodge 3″ in a 1961 study of the system’s five globular clusters by Paul Hodge. Since that time, yet another globular has been discovered! Good luck…

Wednesday, December 5 – How about something a little more suited to the mid-sized scope tonight? Set your sights on Alpha Fornacis and let’s head about 3 fingerwidths northeast (RA 03 33 14.65 Dec -25 52 18.0) for NGC 1360.

In a 6? telescope, you’ll find the 11th magnitude central spectroscopic double star of this planetary nebula to be very easy – but be sure to avert because the nebula itself is very elongated. Like most of my favorite things, this planetary is a rule-breaker since it doesn’t have an obvious shell structure. But why? Rather than believe it is not a true planetary by nature, studies have shown that it could quite possibly be a very highly evolved one – an evolution which has allowed its gases to begin to mix with the interstellar medium. Although faint and diffuse for northern observers, those in the south will recognize this as Bennett 15!

Tonight let’s take advantage of early dark and venture further into Cassiopeia. Returning to Gamma, we will move towards the southeast and identify Delta. Also known as Ruchbah, this long-term and very slight 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. As the last object in the original Messier catalog, M103 (NGC 581) was actually credited to Mechain in 1781. Easily spotted in binoculars and small scopes, this rich open cluster is around magnitude 7, making it a prime study object. At about 8000 light-years away and spanning approximately 15 light-years, M103 offers up superb views in a variety of magnitudes and colors, with a notable red in the south and a pleasing yellow and blue double to the northwest.

Viewers with telescopes and larger binoculars are encouraged to move about a degree and half east of M103 to view a small and challenging chain of open clusters, NGCs 654 (Right Ascension: 1 : 44.1 – Declination: +61 : 53), 663 and 659! Surprisingly larger than M103, NGC 663 (Right Ascension: 1:46.0 – Declination: +61:15) is a lovely fan-shaped concentration of stars with about 15 or so members that resolve easily to smaller aperture. For the telescope, head north for NGC 654, (difficult, but not impossible to even a 114mm scope) which has a bright star on its southern border. South of NGC 663 is NGC 659 (Right Ascension: 1 : 44.2 – Declination: +60 : 42) which is definitely a challenge for small scopes, but its presence will be revealed just northeast of two conspicuous stars in the field of view.

Thursday, December 6 – For northern observers clamoring for brighter stellar action, look no further tonight than the incredible “Double Cluster” about four fingerwidths southeast of Delta Cassiopeiae (Right Ascension: 2 : 22.4 – Declination: +57 : 07). At a dark sky site, this incredible pair is easily located visually and stunning in any size binoculars and telescopes. As part of the constellation of Perseus, this double delight is around 7000 light-years away and less than 100 light-years separates the pair. While open clusters in this area are not really a rarity, what makes the “Double Cluster” so inviting is the large amount of bright stars within each of them. Well known since the very beginnings of astronomy, take the time to have a close look at both Chi (NGC 884) and H Persei very carefully. Note how many colorful stars you see, and the vast array of double, multiple and variable systems!

Now, let’s return again to Cassiopeia and start at the central-most bright star, Gamma. Four degrees southeast is our marker for this starhop, Phi Cassiopeiae. By aiming binoculars or telescopes at this star, it is very easy to locate an interesting open cluster, NGC 457 (Right Ascension: 1 : 19.1 – Declination: +58:20), because they will be in the same field of view.

This bright and splendid galactic cluster has received a variety of names over the years because of its uncanny resemblance to a figure. Some call it an “Angel,” others see it as the “Zuni Thunderbird;” I’ve heard it called the “Owl” and the “Dragonfly,” but perhaps my favorite is the “E.T. Cluster,” As you view it, you can see why! Bright Phi and HD 7902 appear like “eyes” in the dark and the dozens of stars that make up the “body” appear like outstretched “arms” or “wings.” (For E.T. fans? Check out the red “heart” in the center.)

All this is very fanciful, but what is NGC 457, really? Both Phi and HD 7902 may not be true members of the cluster. If 5th magnitude Phi were actually part of this grouping, it would have to have a distance of approximately 9300 light-years, making it the most luminous star in the sky, far outshining even Rigel! To get a rough idea of what that means, if we were to view our own Sun from this far away, it would be no more than magnitude 17.5. The fainter members of NGC 457 comprise a relatively young star cluster that spans about 30 light-years. Most of the stars are only about 10 million years old, yet there is an 8.6 magnitude red supergiant in the center. No matter what you call it, NGC 457 is an entertaining and bright cluster that you will find yourself returning to again and again. Enjoy!

Friday, December 7 – Today is the birthday of Gerard Kuiper. Born 1905, Kuiper was a Dutch-born American planetary scientist who discovered moons of both Uranus and Neptune. He was the first to know that Titan had an atmosphere, and he studied the origins of comets and the solar system.

Tonight let’s honor his achievements as we have a look at another bright open cluster known by many names: Herschel VII.32, Melotte 12, Collinder 23, and NGC 752. You’ll find it three fingerwidths south (RA 01 57.8 Dec +37 41) of Gamma Andromedae…

Under dark skies, this 5.7 magnitude cluster can just be spotted with the unaided eye, is revealed in the smallest of binoculars, and can be completely resolved with a telescope. Chances are it was first discovered by Hodierna over 350 years ago, but it was not cataloged until Sir William gave it a designation in 1786. But give credit where credit is due… For it was Caroline Herschel who observed it on September 28, 1783! Containing literally scores of stars, galactic cluster NGC 752 could be well over a billion years old, strung out in chains and knots in an X pattern of a rich field. Take a close look at the southern edge for orange star 56: while it is a true binary star, the companion you see is merely optical. Enjoy this unsung symphony of stars tonight!

Now, let’s go back to Cassiopeia. Remembering Alpha’s position as the westernmost star, go there with your finderscope or binoculars and locate bright Sigma and Rho (each has a dimmer companion). They will appear to the southwest of Alpha. It is between these two stars that you will find NGC 7789 (RA 23 57 24.00 Dec +56 42 30.0).

Absolutely one of the finest of rich galactic opens bordering on a loose globular, NGC 7789 has a population of about 1000 stars and spans a mind-boggling 40 light-years. At well over a billion years old, the stars in this 5000 light-year distant galactic cluster have already evolved into red-giants or super-giants. Discovered by Caroline Herschel in the 18th century, this huge cloud of stars has an average magnitude of 10, making it a great large binocular object, a superb small telescope target, and a total fantasy of resolution for larger instruments.

Saturday, December 8 – Today in history (1908) marks “first light” for the 60? Hale Telescope at Mt. Wilson Observatory. Not only was it the largest telescope of the time, but it ended up being one of the most productive of all. Almost 100 years later, the 60? Hale is still in service as a public outreach instrument. If we could use the 60? tonight to study, where would we go? My choice would be the Fornax Galaxy Cluster!

Containing around 20 galaxies brighter than 13th magnitude in a one degree field, here is where a galaxy hunter’s paradise begins! About a degree and a half north of Tau Fornacis is the large, bright and round spiral NGC 1398 (Right Ascension: 3 : 38.9 – Declination: -26 : 20). A little more than a degree west-northwest is the easy ring of the planetary nebula NGC 1360. Look for the concentrated core and dark dustlane of NGC 1371 a degree north-northeast – or the round NGC 1385 which accompanies it. Why not visit Bennett 10 or Caldwell 67 as we take a look at NGC 1097 (Right Ascension: 2:46.3 – Declination: -30:17) about 6 degrees west-southwest of Alpha? This one is bright enough to be caught with binoculars!

Telescopes will love NGC 1365 (Right Ascension: 3:33.6 – Declination: -36:08) at the heart of the cluster proper. This great barred spiral gives an awesome view in even the smallest of scopes. As you slide north, you will encounter a host of galaxies, NGCs 1386, 1389, 1404, 1387, 1399, 1379, 1374, 1381 and 1380. There are galaxies everywhere! But, if you lose track? Remember the brightest of these are two ellipticals – 1399 and 1404. Have fun!

Now, let’s 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 25.10 Dec +56 33 54.0). This distinctive cloud of stars and ghostly nebulae make this NGC object a fine challenge!

The last things we will study are two small elliptical galaxies that are achievable in mid-sized scopes. Locate Omicron Cassiopeiae about 7 degrees north of M31 and relocate our earlier study, a galactic pair that is associated with the Andromeda group – NGC 185 (RA 00 38 57.40 Dec +48 20 14.4) and NGC 147 (RA 00 33 11.79 Dec +48 30 24.8). The constellation of Cassiopeia contains many, 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, for there are many bright asterisms best enjoyed at low power. Scopists will return to “rock with the Queen” year after year for its many challenging treasures. Enjoy it tonight!

Sunday, December 9 – Southern Hemisphere viewers, you’re in luck! This is the maximum of the Puppid-Velid meteor shower. With an average fall rate of about 10 per hour, this particular meteor shower could also be visible to those far enough south to see the constellation of Puppis. Very little is known about this shower except that the streams and radiants are very tightly bound together. Since studies of the Puppid-Velids are just beginning, why not take the opportunity to watch? Viewing will be possible all night long and although most of the meteors are faint, this one is known to produce an occasional fireball.

Since we’re favoring the south tonight, let’s set northern observers toward a galaxy cluster – Abell 347 – located almost directly between Gamma Andromedae and M34. Here you will find a grouping of at least a dozen galaxies that can be fitted into a wide field view. Let’s tour a few…

The brightest and largest is NGC 910 (Right Ascension: 2 : 25.4 – Declination: +41:50), a round elliptical with a concentrated nucleus. To the northwest you can catch faint, edge-on NGC 898. NGC 912 is northeast of NGC 910, and you’ll find it quite faint and very small. NGC 911 to the north is slightly brighter, rounder, and has a substantial core region. NGC 909 further north is fainter, yet similar in appearance. Fainter yet is more northern NGC 906, which shows as nothing more than a round contrast change. Northeast is NGC 914, which appears almost as a stellar point with a very small haze around it. To the southeast is NGC 923 which is just barely visible with wide aversion as a round contrast change. Enjoy this Abell quest!

And the countdown is on… Enjoy these last few weeks of the SkyWatcher, cuz’ the old woman is going to retire at the end of this year! Until then? Clear skies!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: November 19-25, 2012



Crater Curtius courtesy of Damian Peach

Greetings, fellow SkyWatchers! It’s going to be a great week to study the Moon – and bright Jupiter is just begging for some quality eyepiece time. Need more? Then why don’t we study some very interesting variable stars, too? It’s all out there… Just waiting on you!

Monday, November 19 – Now we’re ready for some serious lunar study. Our first order of business will be to identify crater Curtius. Directly in the center of the Moon is a dark-floored area known as the Sinus Medii. South of it will be two conspicuously large craters – Hipparchus to the north and ancient Albategnius to the south. Trace along the terminator toward the south until you have almost reached its point (cusp) and you will see a black oval. This normal looking crater with the brilliant west wall is equally ancient crater Curtius. Because of its high southern latitude, we shall never see the entire interior of this crater – and neither has the Sun! It is believed the inner walls are quite steep, and so crater Curtius’ full interior has never been illuminated since its formation billions of years ago. Because it has remained dark, we can speculate there may be “lunar ice” (water ice possibly mixed with regolith) pocketed inside its many cracks and rilles which date back to the Moon’s formation!

Because our Moon has no atmosphere, the entire surface is exposed to the vacuum of space. When sunlit, the surface reaches up to 385 K, so any exposed lunar ice would vaporize and be lost because the Moon’s gravity could not hold it. The only way for ice to exist would be in a permanently shadowed area. Near Curtius is the Moon’s south pole, and imaging from the Clementine spacecraft showed around 15,000 square kilometers of area where such conditions could exist. So where did this ice come from? The lunar surface never ceases to be pelted by meteorites – most of which contain water-related ice. As we know, many craters were formed by just such impacts. Once hidden from the sunlight, this ice could continue to exist for millions of years.

Now turn your eyes or binoculars just west of bright Aldebaran and have a look at the Hyades Star Cluster. While Aldebaran appears to be part of this large, V-shaped group, it is not an actual member. The Hyades cluster is one of the nearest galactic clusters, and it is roughly 130 light-years away in the center. This moving group of stars is drifting slowly away towards Orion, and in another 50 million years it will require a telescope to view!

Tuesday, November 20 – Today celebrates another significant astronomer’s birth – Edwin Hubble. Born 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 then could calculate the velocity-distance relation for galaxies. This has become known as “Hubble’s Law” and demonstrates the expansion of our Universe.

Tonight we’re going to ignore the Moon and head just a little more than a fistwidth west of the westernmost bright star in Cassiopeia to have a look at Delta Cephei (RA 22 29 10.27 Dec +58 24 54.7). 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. When it is its dimmest, 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 1000 light-years away, and doesn’t even require a telescope! (But even binoculars will show its optical companion.)

Wednesday, November 21 – Before we go star hopping this evening, let’s go south on the lunar globe in hopes of catching a very unusual event. On the southern edge of Mare Nubium is the old walled plain Pitatus. Power up. On the western edge you will see smaller and equally old Hesiodus. Almost central along their shared wall there is a break to watch for when the terminator is close. For a brief moment, sunrise on the Moon will pass through this break creating a beam of light across the crater floor in a beautiful phenomenon known as the “Hesiodus Sunrise Ray.” For a very brief moment, a shaft of sunlight will shine through this break and create an experience you will never forget. If the terminator has moved beyond it at your observing time, then look to the south for small Hesiodus A. This is an example of an extremely rare double concentric crater. This formation is caused by one impact followed by another, slightly smaller impact, at exactly the same location.

Now, let’s continue our stellar studies with the central-most star in the lazy “W” of Cassiopeia – Gamma…

At the beginning of the 20th century, the light from Gamma appeared to be steady, but in the mid-1930s it took an unexpected rise in brightness. In less than 2 years it jumped by a magnitude! Then, just as unexpectedly, it dropped back down again in roughly the same amount of time. A performance it repeated some 40 years later!

Gamma Cassiopeiae isn’t quite a giant and is still fairly young on the evolutionary scale. Spectral studies show violent changes and variations in the star’s structure. After its first recorded episode, it ejected a shell of gas which expanded Gamma’s size by over 200% – yet it doesn’t appear to be a candidate for a nova event. The best estimate now is that Gamma is around 100 light-years away and approaching us at a very slow rate. If conditions are good, you might be able to telescopically pick up its disparate 11th magnitude visual companion, discovered by Burnham in 1888. It shares the same proper motion – but doesn’t orbit this unusual variable star. For those who like a challenge, visit Gamma again on a dark night! Its shell left two bright (and difficult!) nebulae, IC 59 and IC 63, to which we will return at the end of the month.

Thursday, November 22 – Tonight when you’re studying the Moon, return to our landmark Copernicus and travel south along the western shore of Mare Cognitum, the “Sea That Has Become Known” and look along the terminator for the Montes Riphaeus – “The Mountains In The Middle of Nowhere.” But are they really mountains? Let’s take a closer look. At the widest, this unusual range spans about 38 kilometers and runs for a distance of around 177 kilometers. Less impressive than most lunar mountain ranges, some peaks reach up to 1250 meters high, making these summits about the same height as our volcano Mt. Kilauea. While we are considering volcanic activity, consider that these peaks are all that is left of Mare Cognitum’s walls after lava filled it in. At one time this may have been amongst the tallest of lunar features!

Once you’ve studied the Montes Riphaeus, you’ll begin noticing another lunar crater that looks a whole lot like a smaller version of Copernicus – the highly under-rated crater Bullialdus. Located close to the center of Mare Nubium, even binoculars can make out Bullialdus when near the terminator. If you’re scoping – power up – this one is fun! Very similar to Copernicus, Bullialdus’ has thick, terraced walls and a central peak. If you examine the area around it carefully, you can note it is a much newer crater than shallow Lubiniezsky to the north and almost non-existent Kies (a real challenge) to the south. On Bullialdus’ southern flank, it’s easy to make out its A and B craterlets, as well as the interesting little Koenig to the southwest.

Friday, November 23 – 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, testing experimental television techniques and infrared equipment. Operating for 376 days, Tiros II sent back thousands of pictures of Earth’s cloud cover and was successful in its experiments to control the orientation of the satellite spin and its infrared sensors. Oddly enough, a similar mission – Meteosat 1 – also 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 on-line tools from NASA you can be alerted by e-mail whenever a bright satellite makes a pass for your specific area. It’s fun!

When you are ready to sail again, we’ll head to the Moon and cross the the western edge of the second largest lunar sea – Mare Imbrium – as we head northeast for the “lighthouse” points set on either side of the landmark “Bay of Rainbows”. They guard the opening to Sinus Iridum and they have names. The easternmost is Promentorium LaPlace, named for Pierre LaPlace. Little more than 56 kilometers in diameter, it rises above the gray sands some 3019 meters; almost identical in height to Buttermilk Mountain near Aspen. Promontorium Heraclides to the west covers roughly the same area, yet rises to little more than half of LaPlace’s height.

Saturday, November 24 – Tonight grab your telescope and head for the Moon and take another look at a feature you might have missed earlier in the year. ! Look west of very bright punctuation of crater Aristarchus for less prominent crater Herodotus. Just to the north you will see a fine white thread known as Schroter’s Valley. This inconspicuous feature winds its way across the Aristarchus plain for about 160 kilometers and measures about 3 to 8 kilometers wide, and about 1 kilometer deep. Schroter’s Valley is an example of a collapsed lava tube. It may have broken open when lava crossed the surface – or it may have settled downwards when a major meteor strike caused a shock wave. What we are looking at is a long, narrow cave on the surface which is very apparent when the lighting is correct.

Ready to aim for a bullseye? Then head for the bright, reddish star Aldebaran. Set your eyes, scopes or binoculars there and let’s look into the “eye” of the Bull.

Known to the Arabs as Al Dabaran, or “the Follower,” Alpha Tauri took its name for the fact that it appears to follow the Pleiades across the sky. In Latin it was Stella Dominatrix, yet the old English knew it as Oculus Tauri, or very literally the “eye of Taurus.” No matter which source of ancient astronomy lore we explore, there are references to Aldeberan.

As the 13th brightest star in the sky, it almost appears from Earth to be a member of the V-shaped Hyades star cluster, but its association is merely coincidental, since it is about twice as close to us as the cluster. In reality, Aldeberan is on the small end as far as K5 stars go, and like many other orange giants could possibly be a variable. Aldeberan is also known to have five close companions, but they are faint and very difficult to observe with backyard equipment. At a distance of approximately 68 light-years, Alpha is slightly less than 45 times larger than our own Sun and approximately 425 times brighter. Because of its position along the ecliptic, Aldeberan is one of the very few stars of first magnitude that can be occulted by the Moon.

Sunday, November 25 – As the Moon nears Full, it becomes more and more difficult to study, but there are still some features that we can take a look at. Before we go to our binoculars or telescopes, just stop and take a look. Do you see the “Cow Jumping over the Moon”? It is strictly a visual phenomenon—a combination of dark maria which looks like the back, forelegs and hindlegs of the shadow of that mythical animal.

While Cassiopeia is in prime position for most northern observers, let’s return tonight for some additional 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 this 12″ diameter, magnitude 13.5 planetary nebula 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 and continue the same distance until you stop at visible Iota. 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 to 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 of stars in the field. Their names are SU (southernmost) and RZ (northernmost) Cassiopeiae and both are unique! SU is a pulsing Cepheid variable located about 1000 light-years away and will show a distinctive red coloration. RZ is a rapidly eclipsing binary that can change from magnitude 6.4 to magnitude 7.8 in less than two hours. Wow!

Until next week? Clear skies!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: November 12-18, 2012

Four day Moon courtesy of Peter Lloyd

Greetings, fellow SkyWatchers! While we might have to contend with the Moon again, it’s still going to be a very exciting week because the Leonid Meteor Shower is back in town! The beginning of the week brings on the Pegasid meteors and we can all use a “warm up”! There’s plenty of things to do, so whenever you’re ready, just meet me in the back yard.

Monday, November 12 – Wouldn’t we all have loved to have been there in 1949 when the first scientific observations were made with the Palomar 5-meter (200-inch) telescope? Or to have seen what Voyager 1 saw as it made its closest approach to Saturn on this date in 1980? To watch Space Shuttle Columbia launch in 1981? Or even better, to have been around in 1833 – the night of the Great Leonid Meteor Shower! But this is here and now, so let’s make our own mark on the night sky as we view the waning Moon.

This evening have a look at the lunar surface and the southeast shoreline of Mare Crisium for Agarum Promontorium. To a small telescope it will look like a bright peninsula extending northward across the dark plain of Crisium’s interior, eventually disappearing beneath the ancient lava flow. Small crater Fahrenheit can be spotted at high power to the west of Agarum, and it is just southeast of there that Luna 24 landed. If you continue south of Agarum along the shoreline of Crisium you will encounter 15 kilometer high Mons Usov. To its west is a gentle rille known as Dorsum Termier – where the Luna 15 mission remains lie. Can you spot 23 kilometer wide Shapely further south?

While skies are fairly dark be sure to keep watch for members of the Pegasid meteor shower – the radiant is roughly near the Great Square. This stream endures from mid-October until late November, and used to be quite spectacular.

Tuesday, November 13 – Today is the birthday 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 as we take a look at a star that is in nuclear decay – Alpha Ceti.

Its name is Menkar, and this second 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 exist in such circumstances – this was 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 worth your time!

Wednesday, November 14 – Ready to aim for a bullseye? Then follow the “Archer” and head right for the bright, reddish star Aldebaran. Set your eyes, scopes or binoculars there and let’s look into the “eye” of the Bull. Known to the Arabs as Al Dabaran, or “the Follower,” Alpha Tauri got its name because it appears to follow the Pleiades across the sky. In Latin it was called Stella Dominatrix, yet the Olde English knew it as Oculus Tauri, or very literally the “eye of Taurus.” No matter which source of ancient astronomical lore we explore, there are references to Aldebaran.

As the 13th brightest star in the sky, it almost appears from Earth to be a member of the V-shaped Hyades star cluster, but this association is merely coincidental, since it is about twice as close to us as the cluster is. In reality, Aldebaran is on the small end as far as K5 stars go, and like many other orange giants, it could possibly be a variable. Aldebaran is also known to have five close companions, but they are faint and very difficult to observe with backyard equipment. At a distance of approximately 68 light-years, Alpha is “only” about 40 times larger than our own Sun and approximately 125 times brighter. Because of its position along the ecliptic, Aldebaran is one of the very few stars of first magnitude that can be occulted by the Moon.

This evening on the Moon we will be returning to familiar features Theophilus, Cyrillus and Catharina. Why not take the time to really power up on them and look closely? Curving away just to the southwest of Catharina on the terminator is another lunar challenge feature, Rupes Altai, or the Altai Scarp. Look for smaller craters beginning to emerge, such as Kant to the northwest, Ibn-Rushd just northwest of Cyrillus and Tacitus to the west.

Thursday, November 15 – Today marks a very special birthday in history. 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, the motion of the Sun in the Milky Way in 1785, 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 towards Cassiopeia as we remember this great astronomer…

Almost everyone is familiar with the legend of Cassiopeia and how the Queen came to be bound in her chair, destined for an eternity to turn over and over in the sky, but did you know that Cassiopeia holds a wealth of double stars and galactic clusters? Seasoned sky watchers have long been familiar with this constellation’s many delights, but let’s remember that not everyone knows them all, and tonight let’s begin our exploration of Cassiopeia with two of its primary stars.

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

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

Friday, November 16 – 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.

And now 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 orbital period. Although it was once assumed that we would merely add around 33 years to each observed “shower,” we later came to realize that the debris formed a cloud that lagged behind the comet and dispersed irregularly. With each successive pass of Tempel-Tuttle, new filaments of debris were left in space along with the old ones, creating different “streams” that the orbiting Earth passes through at varying times, which makes blanket predictions unreliable at best.

Saturday, November 17 – If you didn’t stay up late, then get up early this morning to catch the Leonids. Each year during November, we pass through the filaments of debris – both old and new – and the chances of impacting a particular stream from any one particular year of Tempel-Tuttle’s orbit becomes a matter of mathematical 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 is impossible to calculate.

We may never know precisely where and when the Leonids might strike, but we do know that a good time to look for this activity is well before dawn on November 17, 18 and 19th. With the Moon mostly out of the way, wait until the radiant constellation of Leo rises and the chances are good of spotting one of the offspring of periodic comet Tempel-Tuttle. Your chances increase significantly by traveling a dark sky location, but remember to dress warmly and provide for your viewing comfort.

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

Sunday, November 18 – If you got clouded out of the Leonids yesterday morning, there is no harm in trying again before dawn! The meteor stream varies, and your chances are still quite good of catching one of these bright meteors.

Tonight let’s head toward an optical pairing of stars known as Zeta and Chi Ceti, a little more than a fistwidth northeast of bright Beta. Now have a look with binoculars or small scopes because you’ll find that each has its own optical companion!
Now drop south-southwest less than a fistwidth to have a look at something so unusual that you can’t help but be charmed – the UV Ceti System (RA 01 39 01 Dec -17 57 01).

What exactly is it? Also known as L 726-8, you are looking at two of the smallest and faintest stars known. This dwarf red binary system is the sixth nearest star to our solar system and resides right around nine light-years away. While you are going to need at least an intermediate-size scope to pick up these near 13th magnitude points of light, don’t stop observing right after you locate it. The fainter member of the two is what is known as a “Luyten’s Flare Star” (hence the “L” in its name). Although it doesn’t have a predictable timetable, this seemingly uninteresting star can jump two magnitudes in less than 60 seconds and drop back to “normal” within minutes – the cycle repeating possibly two or three times every 24 hours. A most incredible incident was recorded in 1952 when UV jumped from magnitude 12.3 to 6.8 in just 20 seconds!

Until next week? Wishing you clear skies!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: October 29 – November 4, 2012

The Andromeda Galaxy Courtesy of Bob Kocar

Greetings, fellow SkyWatchers! Are you ready for some spooky targets this week? Then follow along as we take a look at the “Little Eyes”, the “Skull Nebula” and a star that’s as red as a drop of blood! If the weather permits, we’ll also be enjoying the Taruid Meteor Shower! Time to dust off those optics and meet me in the backyard…

Monday, October 29 – October’s Full Moon is known as the “Hunter’s Moon” or the “Blood Moon,” its name came from a time when hunters would stalk the fields by Luna’s cold light in search of prey before the winter season began. Pick a place at sunset to watch it rise – a place having a stationary point with which you can gauge its progress. Make note of the time when the first rim appears and then watch how quickly it gains altitude! How long does it take before it rises above your marker?

On this night in 1749, the French astronomer Le Gentil was at the eyepiece of an 18? focal length telescope. His object of choice was the Andromeda Galaxy, which he believed to be a nebula. Little did he know at the time that his descriptive notes also included M32, a satellite galaxy of M31. It was the first small galaxy discovered, and it would be another 175 years before these were recognized as such by Edwin Hubble.

Even though it’s very bright tonight, take the time to view the Andromeda Galaxy for yourself. Located just about a degree west of Nu Andromeda, this ghost set against the starry night was known as far back as 905 AD, and was referred to as the “Little Cloud.” Located about 2.2 million light-years from our solar system, this expansive member of our Local Galaxy Group has delighted observers of all ages throughout the years. No matter if you view with just your eyes, a pair of binoculars or a large telescope, M31 still remains one of the most spectacular galaxies in the night.

Tuesday, October 30 – Tonight let’s have a look at the big, fat Moon as we return again with binoculars to identify the maria once again. Take the time to repeat the names to yourself and to study a map. One of the keys to successfully learning to identify craters is by starting with large, easily recognized features. Even though the Moon is very bright when full, try using colored or Moon filters with your telescope to have a look at the many surface features which throw amazing patterns across its surface. If you have none, a pair of sunglasses will suffice.

Look for things you might not ordinarily notice – such as the huge streak which emanates from crater Menelaus. Look at the pattern projected from Proclus – or the intense little dot of little-known Pytheas north of Copernicus. It’s hard to miss the blinding beacon of Aristarchus! Check the southeastern limb where the edge of Furnerius lights up the landscape…or how a nothing crater like Censorinus shines on the southeast shore of Tranquillitatis, while Dionysus echoes it on the southwest. Could you believe Manlius just north of central could be such a perfect ring – or that Anaxagoras would look like a northern polar cap? On the eastern limb we see the bright splash ray patterns surrounding ancient Furnerius – yet the rays themselves emanate from the much younger crater Furnerius A. All over the visible side, we see small points light up: a testament to the Moon’s violent past written in its scarred lines. Take a look now at the western limb…for the sunrise is about to advance around it.

Wednesday, October 31 – Happy Halloween! Many cultures around the world celebrate this day with a custom known as “Trick or Treat.” Tonight instead of tricking your little ghouls and goblins, why not treat them to a sweet view through your telescope or binoculars? What Halloween would be complete without a witch?! Easily found from a modestly dark site with the unaided eye, the Pleiades can be spotted well above the northeastern horizon within a couple of hours of nightfall. To average skies, many of the 7 bright components will resolve easily without the use of optical aid, but to telescopes and binoculars? M45 (Right Ascension: 03 : 47.0 – Declination: +24 : 07) is stunning…

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

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

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

Thursday, November 1 – On this day in 1977, Charles Kowal made a wild discovery – Chiron. This represented the first discovery of a multitude of tiny, icy bodies that lie in the outer reaches of our solar system. Collectively known as Centaurs, they reside in unstable orbits between Jupiter and Neptune and are almost certainly “refugees”” from the Kuiper Belt.

Tonight let’s go for something small, but white-hot as we head for a dwarf star and planetary nebula, NGC 246. You’ll find it just a bit more than a fistwidth north-northeast of Beta Ceti (RA 00 47 03.34 Dec -11 52 18.9).

First discovered by Sir William Herschel and cataloged as object V.25, this 8th magnitude planetary nebula has a wonderful patchy, diffuse structure that envelops four stars. Around 1600 light-years away, the nebulosity you can see around the exterior edges was once the outer atmosphere of a star much like our own Sun. At the center of the nebula lies the responsible star – the fainter member of a binary system. While it is now in the process of becoming a white dwarf, we can still enjoy the product of this expanding shell of gas that is often called the “Skull Nebula.”

Friday, November 2 – Celestial scenery alert! If you’re up when the Moon rises, be sure to look for the close pairing of Jupiter and the Moon – they’re only about a fingerwidth apart! For a few viewers in the southernmost Africa region, this is an occultation event, so be sure to check resources for websites like IOTA which will give you times for locations in your area. What a great photographic opportunity… Clear skies!
Today celebrates the birth of an astronomy legend – Harlow Shapely. Born in 1885, the American-born Shapley paved the way in determining distances to stars, clusters, and the center of our Milky Way galaxy. Among his many achievements, Shapely was also the Harvard College Observatory director for many years. Today in 1917 also represents the night first light was seen through the Mt. Wilson 100? telescope.

Of course, Dr. Shapley spent his fair share of time on the Hooker telescope as well. One of his many points of study was globular clusters, their distance, and their relationship to the halo structure of our galaxy. Tonight let’s have a look at a very unusual little globular located about a fistwidth south-southeast of Beta Ceti and just a couple of degrees north-northwest of Alpha Sculptor (RA 00:52:47.5 Dec -26:35:24), as we have a look at NGC 288.

Discovered by William Herschel on October 27, 1785, and cataloged by him as H VI.20, the class X globular cluster blew apart scientific thinking in the late 1980?s as a study of perimeter globulars showed it to be more than 3 million years older than similar globulars – thanks to the color magnitude diagrams of Hertzsprung and Russell. By identifying both its blue and red branches, it was shown that many of NGC 288?s stars are being stripped away by tidal forces and contributing to the formation of the Milky Way’s halo structure. In 1997, three additional variable stars were discovered in this cluster.
At magnitude 8, this small globular is easy for southern observers, but faint for northern ones. If you are using binoculars, be sure to look for the equally bright spiral galaxy NGC 253 to the globular’s north.

Saturday, November 3 – On this day in 1955, one of the few documented cases of a person being hit by a meteorite occurred. What are the odds on that? In 1957 the Russian space program launched its first “live” astronaut into space – Laika. Carried on board Sputnik 2, our canine hero was the first living creature to reach orbit. The speedily developed Sputnik 2 was designed with sensors to transmit the ambient pressure, breathing patterns and heartbeat of its passenger, and also had a television camera on board to monitor its occupant. The craft also studied ultraviolet and x-ray radiation to further assess the impact of space flight upon live occupants. Unfortunately, the technology of the time offered no way to return Laika to Earth, so she perished in space. On April 14, 1958, Laika and Sputnik 2 returned to Earth in a fiery re-entry after 2,570 orbits.

Since we’ve got the scope out, let’s go have another look at that galaxy we spied last night!

Discovered by Caroline Herschel on September 23, 1783, NGC 253 (RA 00 47.6 Dec -25 17) is the brightest member of a concentration of galaxies known as the Sculptor Group, near to our own local group and the brightest of all outside it. Cataloged as both H V.1 and Bennett 4, this 7th magnitude beauty is also known as Caldwell 65, and due to both its brightness and oblique angle is often called the “Silver Dollar Galaxy.” As part of the SAC 110 best NGCs, you can even spot this one if you don’t live in the Southern Hemisphere. At around 10 million light-years away, this very dusty, star-forming Seyfert galaxy rocks in even a modest telescope!

Sunday, November 4 – This morning will be the peak of the Southern Taurid meteor shower. Already making headlines around the world for producing fireballs, the Taurids will be best visible in the early morning hours, but the Moon will interfere. The radiant for this shower is, of course, the constellation of Taurus and red giant Aldeberan, but did you know the Taurids are divided into two streams?

It is surmised that the original parent comet shattered as it passed our Sun around 20,000 to 30,000 years ago. The larger “chunk” continued orbiting and is known as periodic comet Encke. The remaining debris field turned into smaller asteroids, meteors and larger fragments that often pass through our atmosphere creating the astounding “fireballs” known as bolides. Although the fall rate for this particular shower is rather low at 7 per hour, these slow traveling meteors (27 km or 17 miles per second) are usually very bright and appear to almost “trundle” across the sky. With the chances high all week of seeing a bolide, this makes a bit of quiet contemplation under the stars worthy of a morning walk. Be sure to look at how close Saturn is to the Moon!

For unaided eye or binocular observers – or those who just wish something a bit “different” tonight – have a look at 19 Pisces. You’ll find it as the easternmost star in the small “circlet” just south of the Great Square of Pegasus.

Also known as TX, you’ll find this one quite delightful for its strong red color. TX is a cool giant star which varies slightly in magnitude on an irregular basis. This carbon star is located anywhere from 400 to 1000 light-years away and rivals even R Leporis’ crimson beauty.

Until next week? Wishing you clear skies!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: October 22-28, 2012

Mare Nectaris - Credit: Damian Peach

Greetings, fellow SkyWatchers! It’s going to be a great week to enjoy lunar studies, but why don’t we take a look at couple of other interesting objects, too? I think this would be the perfect opportunity to chase an asteroid! Not enough? Then get out your zombie hunting equipment and we’ll have a look at the “Demon Star”, too! Whenever you’re ready to learn a little more about the history and mystery of what’s out there, just meet me in the back yard…

Monday, October 22 – Something very special happened today in 2136 B.C. There was a solar eclipse, and for the very first time it was seen and recorded by Chinese astronomers. And probably a very good thing because in those days the royal astronomers were executed for failure to predict! Today is also the birthday of Karl Jansky. Born in 1905, Jansky was an American physicist as well as an electrical engineer. One of his pioneer discoveries was non-Earth-based radio waves at 20.5 MHz, a detection he made while investigating noise sources during 1931 and 1932. And, in 1975, Soviet Venera 9 was busy sending Earth the very first look at Venus’ surface.

Also today in 1966 Luna 12 was launched towards the Moon – as so shall we be. We’ll continue our lunar explorations as we look for the “three ring circus” of easily identified craters – Theophilus, Cyrillus, and Catherina – a challenging crater which spans 114 kilometers and goes below the lunar surface by 4730 meters. Are you ready to discover a very conspicuous lunar feature that was never officially named? Cutting its way across Mare Nectaris from Theophilus to shallow crater Beaumont in the south, you’ll see a long, thin, bright line. What you are looking at is an example of a lunar dorsum – nothing more than a wrinkle or low ridge. Chances are good that this ridge is just a “wave” in the lava flow that congealed when Mare Nectaris formed. This particular dorsa is quite striking tonight because of low illumination angle. Has it been named? Yes. It is unofficially known as “Dorsum Beaumont,” but by whatever name it is called, it remains a distinct feature you’ll continue to enjoy! Also to the far south along the terminator you will see Mutus, a small crater with black interior and bright, thin west wall crest. Angling further southwest from Mutus, look for a “bite” taken out of the terminator. This is crater Manzinus.

Tuesday, October 23 – Now it’s time to look for Mare Vaporum – “The Sea of Vapors” – on the southwest shore of Mare Serenitatis. Formed from newer lava flow inside an old crater, this lunar sea is edged to its north by the mighty Apennine Mountains. On its northeastern edge, look for the now washed-out Haemus Mountains. Can you see where lava flow has reached them? This lava has come from different time periods and the slightly different colorations are easy to spot even with binoculars.

Further south and edged by the terminator is Sinus Medii – the “Bay in the Middle” of the visible lunar surface. Central on the terminator, and the adopted “center” of the lunar disc, this the point from which latitude and longitude are measured. This smooth plain may look small, but it covers about as much area as the states of Massachusetts and Connecticut combined. During full daylight temperatures in Sinus Medii can reach up to 212 degrees! On a curious note, in 1930 Sinus Medii was chosen by Edison Petitt and Seth Nicholson for a surface temperature measurement at full Moon. Experiments of this type were started by Lord Rosse as early as 1868, but on this occasion Petit and Nicholson found the surface to be slightly warmer than boiling water. Around a hundred years after Rosse’s attempt, Surveyor 6 successfully landed in Sinus Medii on November 9, 1967, and became the very first probe to “lift off” from the lunar surface.

Wednesday, October 24 – Today in 1851, a busy astronomer was at the eyepiece as William Lassell discovered Uranus’ moons Ariel and Umbriel. Although this is far beyond backyard equipment, we can have a look at that distant world. While Uranus’ small, blue/green disc isn’t exactly the most exciting thing to see in a small telescope or binoculars, the very thought that we are looking at a planet that’s over 18 times further from the Sun than we are is pretty impressive! Usually holding close to a magnitude 6, we watch as the tilted planet orbits our nearest star once every 84 years. Its atmosphere is composed of hydrogen, helium and methane, yet pressure causes about a third of this distant planet to behave as a liquid. Larger telescopes may be able to discern a few of Uranus’ moons, for Titania (the brightest) is around magnitude 14.

Let’s begin our lunar studies tonight with a deeper look at the “Sea of Rains.” Our mission is to explore the disclosure of Mare Imbrium, home to Apollo 15. Stretching out 1123 kilometers over the Moon’s northwest quadrant, Imbrium was formed around 38 million years ago when a huge object impacted the lunar surface creating a gigantic basin.

The basin itself is surrounded by three concentric rings of mountains. The most distant ring reaches a diameter of 1300 kilometers and involves the Montes Carpatus to the south, the Montes Ap-enninus southwest, and the Caucasus to the east. The central ring is formed by the Montes Alpes, and the innermost has long been lost except for a few low hills which still show their 600 kilometer diameter pattern through the eons of lava flow. Originally the impact basin was believed to be as much as 100 kilometers deep. So devastating was the event that a Moon-wide series of fault lines appeared as the massive strike shattered the lunar lithosphere. Imbrium is also home to a huge mascon, and images of the far side show areas opposite the basin where seismic waves traveled through the interior and shaped its landscape. The floor of the basin rebounded from the cataclysm and filled in to a depth of around 12 kilometers. Over time, lava flow and regolith added another five kilometers of material, yet evidence remains of the ejecta which was flung more than 800 kilometers away, carving long runnels through the landscape.

Thursday, October 25 – And who was watching the planets in 1671? None other than Giovanni Cassini – because he’d just discovered Saturn’s moon Iapetus.

Tonight let’s discover our own Moon as we take a look at Mare Insularum, the “Sea Of Islands”. Ir will be partially revealed tonight as one of the most prominent of lunar craters – Copernicus – guides the way. While only a small section of this reasonably young mare is now visible southwest of Copernicus, the lighting will be just right to spot its many different colored lava flows. To the northeast is a lunar club challenge: Sinus Aestuum. Latin for the Bay of Billows, this mare-like region has an approximate diameter of 290 kilometers, and its total area is about the size of the state of New Hampshire. Containing almost no features, this area is low albedo and provides very little surface reflectivity. Can you see any of Copernicus’ splash rays beginning to appear yet?

Today is the birthday of Henry Norris Russell. Born in 1877, Russell was the American leader in establishing the modern field of astrophysics. As the namesake for the American Astronomical Society’s highest award (for lifetime contributions to the field), Mr. Russell is the “R” in HR diagrams, along with Mr. Hertzsprung. This work was first used in a 1914 paper, published by Russell.

Tonight let’s have a look at a star that resides right in the middle of the HR diagram as we have a look Beta Aquarii.

Named Sadal Suud (“Luck of Lucks”), this star of spectral type G is around 1030 light-years distant from our solar system and shines 5800 times brighter than our own Sun. The main sequence beauty also has two 11th magnitude optical companions. The one closest to Sadal Suud was discovered by John Herschel in 1828, while the further star was reported by S.W. Burnham in 1879.

Friday, October 26 – It’s big. It’s bright. It’s the Moon! Look for a small, but very bright, small crater that you just can’t miss… Kepler! This great landmark crater named for Johannes Kepler only spans 32 kilometers, but drops to a deep 2750 meters below the surface. It’s a class I crater that’s a geological hotspot! As the very first lunar crater to be mapped by the U.S. Geological Survey, the area around Kepler contains many smooth lava domes reaching no more than 30 meters above the plains. The crater rim is very bright, consisting mostly of a pale rock called anorthosite. The “lines” extending from Kepler are fragments that were splashed out and flung across the lunar surface when the impact occurred. According to records, in 1963 a glowing red area was spotted near Kepler and extensively photographed. Normally one of the brightest regions of the Moon, the brightness value at the time nearly doubled! Although it was rather exciting, scientists later determined the phenomenon was caused by high energy particles from a solar flare reflecting from Kepler’s high albedo surface – a sharp contrast from the dark mare composed primarily of dark minerals of low reflectivity (albedo) such as iron and magnesium. The region is also home to features known as “domes” – similar to Earth’s shield volcanoes – seen between the crater and the Carpathian Mountains. In the days ahead all details around Kepler will be lost, so take this opportunity to have a good look at one awesome small crater.

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

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

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

Although Algol is known to have two additional spectroscopic companions, the true beauty of watching this variable star is not telescopic – but visual. The constellation of Perseus is well placed this month for most observers and appears like a glittering chain of stars that lie between Cassiopeia and Andromeda. To help further assist you, re-locate last week’s study star, Gamma Andromedae (Almach) east of Algol. Almach’s visual brightness is about the same as Algol’s at maximum.

Saturday, October 27 – Tonight let’s skip the Moon and hunt down an asteroid! We’ll be locating Vesta which will be cruising along the southern border of Taurus, just about a handspan north/northwest of Betelgeuse. However, since asteroids are always on the move, the position will need to be calculated for your area, so use your local planetarium programs to get an accurate map. When you’re ready, let’s talk…

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

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

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

Sunday, October 28 – Today in 1971, Great Britain launched its first satellite – Prospero.

Tonight we’ll launch our journey along the southern shore of Mare Humorum and identify ancient crater Vitello. Notice how this delicate ring resembles earlier study Gassendi on the opposite shore. Its slopes have been crushed by the impact that formed crater Lee to its west. As you begin to circle around Mare Humorum and start northward again, you’ll be traveling along the Rupes Kelvin – ending in the spearhead formation of Promentorium Kelvin. Here again is another extremely old feature, a triangular mountainous cape born in the pre-Imbrian period and as much as 4 billion years old. It could be as long as 41 miles and about as wide as 21 miles, but its height is impossible to judge.

Take a breath now, and we’ll look for two more dark patches to guide us on. South of Mare Humorum is darker Paulus Epidemiarum eastward and paler Lacus Excellentiae westward. To their south you will see a complex cojoined series of craters we’ll take a closer look at – Hainzel and Mee. Hainzel was named for Tycho Brahe’s assistant and measures about 70 kilometers in length and sports several various interior wall structures. Power up and look. Hainzel’s once high walls were obliterated on the north-east by the strike that caused Hainzel C and to the north by impact which caused the formation of Hainzel A. To its basic south is eroded Mee – named for a Scottish astronomer. While Crater Mee doesn’t appear to be much more than simple scenery, it spans 172 kilometers and is far older than Hainzel. While you can spot it easily in binoculars, close telescope inspection shows how the crater is completely deformed by Hainzel. Its once high walls have collapsed to the northwest and its floor is destroyed. Can you spot small impact crater Mee E on the northern edge?

Until next week, wishing you clear and steady skies!

Posted on by Tammy Plotner

Weekly SkyWatcher’s Forecast: October 15-21, 2012

Cassiopeia A in Visible Light Courtesy of the Hubble Space Telescope

Greetings, fellow SkyWatchers! Whoops! (she blushes) I got so lost this weekend in researching Comet ISON that I almost forgot to post the forecast! Ah, well… As they say, better late than never, eh? If you do nothing else this week, be sure to catch the close apparition of Mercury and the “Earthshine Moon” on Wednesday and stay up late Saturday night to watch the Orionid Meteor Shower! In case I forget, just meet me in the back yard…

Monday, October 15 –Today in 1963 marks the first detection of an interstellar molecule. This discovery was made by Sander Weinreb (with Barrett, Meeks, and Henry) on the MIT Millstone Hill 84-foot dish. The discovery was made possible by new correlation receiver technology, and picked up a hydroxyl molecule in an absorption band. By using the radio galaxy Cas A as a background continuum source, the detection occurred at 1667.46 MHz and again at 1665.34 MHz. By the dawn of 2000, nearly 200 different interstellar molecules had been identified and many of these are classified as organic.

Tonight is New Moon! Let’s see what’s up there in the region of Cas A using visible light. The nearest bright star to Cas A is Beta Cassiopeiae – the bright star westward of the “W.” To locate the region of Cas A, go about three finger-widths due west of Beta and follow the subtle curve of three 5th magnitude stars. Cas A lies less than one degree south-southwest of the second star in the sequence of three. This star is a complex 5th magnitude multiple star system associated with variable star AR Cas.

Through binoculars, two stars of the AR system are easily resolved – the 4.9 magnitude primary is seen to be led across the sky by a 7.1 magnitude secondary (component C) which is a very tight double itself. Its 8.9 magnitude partner is resolvable in mid-sized scopes. Large aperture scopes may also be able to distinguish a 9.3 magnitude, second (B) component from the primary. Smaller scopes are back in the running again when attempting three 11th magnitude stars – none of which are close to the primary. Intermediate scopes can also hope to pick out a 12.9 magnitude H component northwest of C. 8.9 magnitude F also has a 9.1 magnitude near twin to the east-northeast. If you can see them all you should probably wrap an observatory building around your telescope – if one isn’t there already!

If you like to follow brightness changes in variables – AR Cas is not a good choice. This eclipsing type variable only fluctuates by a tenth of a magnitude over a period of 6 earth days.

Tuesday, October 16 – Let’s begin our evening by having a look at a radio source as we visit a pulsar located almost mid-way between Theta and Beta Capricorni – PSR2045+16.

While pulsars aren’t truly visible objects, there is still something undeniably cool about locating the field in which a rotating neutron star is sending out staccato pulses of radio waves anywhere between .001 and 4 seconds apart. If you have bright star 19 in the binocular field, then you know you’re in the right area for many radio sources, including many nearby quasars… Just imagine the possibilities!

Now let’s drop south-southeast of Beta Capricorni to have a look at a pair of doubles – Rho and Pi.

Northernmost Pi is a multiple system slightly less than 100 light-years away, with each discernable member also being a spectroscopic double. Separated by about an eighth of a light-year, look for a 5th magnitude yellow/white giant with a very close 9th magnitude companion. Further south is Pi, a triple star system which has a traditional name – Okul. Located around 670 light-years away, look for a bright blue/white 5th magnitude primary that is also a spectroscopic double – and its much easier C component, which is around magnitude 8.

Wednesday, October 17 – For naked-eye observers, enjoy the beautiful “Earthshine” Moon and the close apparition of Mercury!

While you’re out, be sure to gaze upon one of the finest of stars, Vega. Facing West at just after sundown, Vega is bright enough to shine even in the city and will appear just slightly below the zenith. The name Vega means “Falling Eagle” and it is the fifth brightest star in the sky. Enjoyed in either telescopes or binoculars, Vega has a wonderful bluish appearance and a lovely halo of spectra. This magnificent star holds a place in ancient legend and blossomed in our imaginations even more recently as it became the “star” of the movie “Contact”. As the western-most point of the “Southern Triangle”, Vega holds a special appeal for those born in the year 1985. Why? Because Vega is 27 light years away, the light you see from it tonight left the year you were born!

Now point those binoculars towards the northwestern corner of Capricornus and have a look a spectacular Alpha!

Although the Alpha 1 and 2 pairing is strictly a visual binary, that won’t stop you from enjoying their slightly yellow and orange colors. Collectively they are named Al Giedi, and the brighter of the pair is Alpha 2 at about 100 light-years distant; while Alpha 1 is around five times further away. Now power up with a telescope and you’ll find that both stars are also visual doubles! While the companion stars to both are around the same magnitude, you’ll find that Alpha 2 is separated by three times as much distance. Be sure to mark your observation lists and enjoy!

Thursday, October 18 – Today in 1959, Soviet Luna 3 began returning the first photographs of the Moon’s far side. Also today – but in 1967 – the Soviets again made history as Venera 4 became the first spacecraft to probe Venus’ atmosphere.

Have you checked out Mars lately? Mars is now leaving the constellation Scorpius and entering Ophiuchus. At more than 2 AU away from Earth, Mars has become quite dim, and its minimal apparent visual brightness is +1.24 magnitude. Can you still spot a few of its more prominent features?

For a true telescope challenge, we’ll have to go out on a limb – the southeastern lunar limb – to have a look at an unusual crater. Named for the French agrochemist and botanist Jean-Baptiste Boussingault, this elliptical-appearing crater actually spans a handsome 71 kilometers. What makes Boussingault so unusual is that it is home to its own large interior crater – A. This double-ring formation gives it a unique stepped, concentric look that’s worth your time!

When we’re done? Let’s go have a look at Gamma Aquilae just for the heck of it. Just northwest of bright Altair, Gamma has the very cool name of Tarazed and is believed to be over 300 light-years away. This K3 type giant will show just a slightly yellow coloration – but what really makes this one special is the low power field!

Friday, October 19 – Our lunar mission for tonight is a revisit on a crater named for historian and theologian Denis Pétau – Petavius! Located almost centrally along the terminator in the southeast quadrant, a lot will depend tonight on your viewing time and the age the Moon itself. Perhaps when you look, you’ll see 177 kilometer diameter Petavius cut in half by the terminator. If so, this is a great time to take a high magnification look at the small range of mountain peaks contained in its center, as well as a deep rima which runs for 80 kilometers across its otherwise fairly smooth surface. To the east lies a long furrow in the landscape. This deep runnel is Palitzsch and its Valles. While the primary crater which forms this deep gash is only 41 kilometers wide, the valley itself stretches for 110 kilometers. Look for crater Haas on Petavius’ southern edge with Snellius to the southwest and Wrottesley along its northwest wall.

Now, let’s go have a look at the northeastern corner of Capricornus as we learn about Delta…

Its proper name is Deneb Algedi and this nearly 3rd magnitude star is a stunning blue/ white. Curiously enough, it’s a rather close star – only about 50 light-years from Earth. Hovering so close to it that we cannot even correctly assess its spectral type is a binary companion whose eclipsing orbit causes Delta to be a very slight variable – with a period of just about one day. In its own way, Delta is rather historic… For it was only 4 degrees north of this star that Uranus was first sighted by Galle in 1846!

Saturday, October 20 – Tonight, let’s check out a lunar map and go hunting! First let’s start with a look at the Mare Fecunditatus region: (1)Taruntius, (2) Secchi, (3) Messier and Messier A, (4) Lubbock, (5) Guttenberg, (6) Montes Pyrenees, (7) Goclenius, (8) Magelhaens, (9) Columbo, (10) Webb, (11) Langrenus, (12) Lohse, (13) Lame, (14) Vendelinus, (15) the Luna 16 landing site

Mare Fecunditatus Region Photographic Map – Image Credit – Greg Konkel

And here is a closer look at the area around Atlas and Hercules: (1) Mare Humboldtianum, (2) Endymion, (3) Atlas, (4) Hercules, (5) Chevalier, (6) Shuckburgh, (7) Hooke, (8) Cepheus, (9) Franklin, (10) Berzelius, (11) Maury, (12) Lacus Somniorum, (13) Daniel, (14) Grove, (15) Williams, (16) Mason, (17) Plana, (18) Burg, (19) Lacus Mortis, (20) Baily, (21) Atlas E, (22) Keldysh, (23) Mare Frigoris, (24) Democritus, (25) Gartner, (26) Schwabe, (27) Thales, (28) Strabo, (29) de la Rue, (30) Hayn.


Atlas and Hercules Region Photographic Map – Image Credit – Greg Konkel

Have fun marking off lunar challenge craters from your list!

After having looked at the Moon, take the time out to view a bright southern star – Fomalhaut (RA 22 57 39 Dec -29 37 20). Also known as “The Lonely One,” Alpha Piscis Austrini seems to sit in a rather empty area in the southern skies, some 23 light-years away. At magnitude 1, this main sequence A3 giant is the southernmost visible star of its type for northern hemisphere viewers, and is the 18th brightest star in the sky. The Lonely One is about twice the diameter of our own Sun, but 14 times more luminous! Just a little visual aid is all that it takes to reveal its optical companion…

Now we are slipping into the stream of Comet Halley and into one of the finest meteor showers of the year. If skies are clear tonight, this would be the perfect chance to begin your observations of the Orionid meteor shower. But, wait for the Moon to set!

Sunday, October 21 – Be sure to be outdoors before dawn to enjoy one of the year’s most reliable meteor showers. The offspring of Comet Halley will grace the early morning hours as they return once again as the Orionid meteor shower. This dependable shower produces an average of 10-20 meteors per hour at maximum and the best activity begins before local midnight on the 20th, and reaches its best as Orion stands high to the south at about two hours before local dawn on the 21st. With the Moon nearly out of the morning picture, this is gonna’ be great!

Although Comet Halley has long since departed our Solar System, the debris left from its trail still remain scattered in Earth’s orbital path around the Sun, allowing us to predict when this meteor shower will occur. We first enter the “stream” at the beginning of October and do not leave it until the beginning of November, making your chances of “catching a falling star” even greater! These meteors are very fast, and although they are faint, it is still possible to see an occasional fireball that leaves a persistent trail.

For best success, try to get away from city lights. Facing south-southeast, simply relax and enjoy the stars of the winter Milky Way. The radiant, or apparent point of origin, for this shower will be near the red giant Alpha Orionis (Betelguese), but meteors may occur from any point in the sky. You will make your meteor watching experience much more comfortable if you take along a lawn chair, a blanket and a thermos of your favorite beverage.

Clouded out? Don’t despair. You don’t always need your eyes or perfect weather to meteor watch. By tuning an FM radio to the lowest frequency possible that does not receive a clear signal, you can practice radio meteor listening! An outdoor FM antenna pointed at the zenith and connected to your receiver will increase your chances, but it’s not necessary. Simply turn up the static and listen. Those hums, whistles, beeps, bongs, and occasional snatches of signals are our own radio signals being reflected off the meteor’s ion trail! Pretty cool, huh?

Por amour du ciel… ~Tammy