Universe Today

February 3, 2009December 24, 2015 by Nancy Atkinson

Smallest Terrestrial Exoplanet Yet Detected

COROT-exo-7b, bottom left dot shadows in front of his central star (artist's impression). Aufgrund der großen Nähe zu seiner Sonne vermuten Forscher Temperaturen von über 1000 Grad Celsius auf dem extrasolaren Planeten. Because of its proximity to large solar researchers suspect temperatures over 1000 degrees Celsius on the extrasolar planets. Bild: Klaudia Einhorn. Image: Klaudia Einhorn.

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The CoRoT satellite has found the smallest terrestrial exoplanet yet, — with a diameter just under twice that of Earth — complete with a rocky surface you could walk on and possibly even oceans to sail across. However, if you traveled there, you might want to bring some protection, as the temperature of this planet is likely very high. CoRoT-Exo-7b is located very close to its parent star, orbiting once every 20 hours. Astronomers estimate temperatures on the planet could be between 1000 and 1500°C and it possibly could be covered in lava or water vapor. This latest exoplanet was detected as it transited in front of its parent star, dimming the light from the star just enough to be noticeable.

The parent star lies about 140 parsecs from Earth, located about half way between the star Sirius in Canis Major and Betelgeuse, the red giant star in Orion.

The internal structure of CoRoT-exo-7b particularly puzzles scientists; they are unsure whether it is an ‘ocean planet’, a kind of planet whose existence has never been proved so far. In theory, such planets would initially be covered partially in ice and they would later drift towards their star, with the ice melting to cover it in liquid.

COROT detects small, transiting exoplanet. Credits: CNES

“This discovery is a very important step on the road to understanding the formation and evolution of our planet,” said Malcolm Fridlund, ESA’s CoRoT Project Scientist. “For the first time, we have unambiguously detected a planet that is ‘rocky’ in the same sense as our own Earth. We now have to understand this object further to put it into context, and continue our search for smaller, more Earth-like objects with COROT,” he added.

About 330 exoplanets have been discovered so far, most of which are gas giants likeJupiter and Neptune. The density of COROT-Exo-7b is still under investigation: it may be rocky like Earth and covered in liquid lava. It may also belong to a class of planets that are thought to be made up of water and rock in almost equal amounts. Given the high temperatures measured, the planet would be a very hot and humid place.

“Finding such a small planet was not a complete surprise”, said Daniel Rouan, researcher at the Observatoire de Paris Lesia, who coordinates the project with Alain Léger, from Institut d’Astrophysique Spatiale (Paris, France). “CoRoT-Exo-7b belongs to a class of objects whose existence had been predicted for some time. COROT was designed precisely in the hope of discovering some of these objects,” he added.

Small terrestrial planets are difficult to detect, and so very few exoplanets found so far have a mass comparable to Earth, Venus, Mars, and Mercury. Most of the methods used to find planets are indirect and sensitive to the mass of the planet. The CoRoT spacecraft can directly measure the size of a planet’s surface, which is an advantage. In addition, its location in space allows for longer periods of uninterrupted observation than from ground.

Astronomers say this discovery is significant because recent measurements have indicated the existence of planets of small masses but their size remained undetermined until now. CoRoT (Convection Rotation and Transits) was launched in December 2006 and consists of a 27 cm-diameter telescope designed to detect tiny changes the brightness of nearby stars. The mission’s main objectives are to search for exoplanets and to study stellar interiors.

Source: ESA

February 3, 2009February 3, 2009 by Nancy Atkinson

Iran Launches Satellite into Orbit

Iran launched its first functioning satellite into orbit late Monday using a modified long-range missile to place a home-produced research and telecommunications satellite into space. Iran now joins a small group of space-faring nations with the ability to build and launch their own satellites. In 2005, Iran used a Russian rocket to launch a satellite, and in August of 2008 Iran reported they launched a dummy satellite into orbit using their own Safir-2 rocket, but other sources said the rocket suffered a catastrophic failure. This most recent launch, however, was the country’s first success in using their own rocket and their own functional satellite, launched from Iranian territory. The launch coincided with a 10-day celebration of the 30th anniversary of Iran’s Islamic revolution, according to the Fars news agency. On Iranian television, Iran’s President Mahmoud Ahmadinejad said the satellite was a “step toward justice and peace.”

Watch video of the launch, which includes several replays:

Continue reading “Iran Launches Satellite into Orbit”

February 2, 2009December 24, 2015 by Tammy Plotner

Vulpecula

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The constellation of Vulpecula is unusual, because it did not belong originally to those created by Ptolemy – but to the works of Johannes Hevelius. Vulpecula was included in Firmamentum Sobiescianum, a 56 page atlas created by Hevelius, which outlined seven new constellations which survived time – and many which did not. Positioned north of the ecliptic plane, it spans 268 square degrees of sky, ranking 55th in constellation size. It has 5 main stars in its asterism and 33 Bayer Flamsteed designated stars within its confines. Vulpecula is bordered by the constellations of Cygnus, Lyra, Hercules, Sagitta, Delphinus and Pegasus. It is best seen at culmination during the month of September.

Since Vulpecula is considered a “modern” constellation, there is no mythology associated with it – although the stellar pattern was very visible to the ancient Greeks and Romans. Late in 17th century, astronomer Johannes Hevelius created the constellation of Vulpecula when he was preparing his own set of star charts known as Firmamentum Sobiescianum At the time, he named it “Vulpecula Cum Ansere” which literally translated to the little fox with the goose – and he illustrated it as a fox with a goose caught in its jaws. At the time, Hevelius did not consider it to be two separate constellations – yet it was later divided into two halves – Vulpecula and Anser “The Goose”. When star charts were once again consolidated, the constellations merged again to be known under to modern named assigned to it by the International Astronomical Union as Vulpecula, yet the primary star retains a reminder be being properly named Anser.

Let’s begin our binocular tour of Vulpecula with a look at the Alpha (“a”) star – Anser. Its name literally translates to “goose”, but this class M giant star is anything but flighty. Residing 297 light years from Earth, Anser puts out 390 times more light energy than our Sun from a size about 45 times larger. It may have a dead helium core about to begin hydrogen fusion – and it may have a dead carbon-oxygen core awaiting a second brightening before turning K class. If you’ve notice another nearby star – good for you! Although it’s only a line of sight companion, 8 Vulpeculae makes checking out Anser a real treat!

Now head on to Collinder 399. This wonderful asterism is often called “Brocchi’s Cluster” or the “Coathanger” and it’s a splendid object in binoculars or a rich field telescope. This unique collection of stars was known as far back as 964 AD when astronomer Al Sufi recorded it, and it was independently rediscovered by Giovanni Hodierna in the seventeenth century. In the 1920s, D. F. Brocchi, an amateur astronomer and chart maker for the American Association of Variable Star Observers, created a map of this object for use in calibrating photometers. Thanks to its expansive size of more than 60 arc minutes, it escaped the catalogues of both Messier and Herschel. Only around a half dozen stars share the same proper motion, which may make it a cluster much like the Pleiades, but studies suggest it is merely an asterism…but one with two binary stars at its heart.

Our next target is the magnificent Messier 27 (RA 19 : 59.6 Dec +22 : 43). This incredible planetary nebula appears like a pale green apple core and is unquestionably the brightest study of its kind. Easily located around a finger-width north of Gamma Sagittae, it’s not the largest of all planetaries but is the largest of its kind on the Messier list. M27’s expanse and luminosity suggest that it is quite close to our own system. Some think it difficult to find, but there is a very simple trick. Look for the primary stars of Sagitta just to the west of bright Albireo. Make note of the distance between the two brightest and look exactly that distance north of the “tip of the arrow” and you’ll find M27.

Discovered in 1764 by Messier in a 3.5 foot focal length telescope, I discovered this 48,000 year old planetary nebula for the first time in a 4″ telescope. I was hooked immediately. Here before my eager eyes was a glowing green “apple core” which had a quality about it that I did not understand. It somehow moved… It pulsated. It appeared “living.” For many years I quested to understand the 850 light-year distant M27, but no one could answer my questions. I researched and learned it was made up of doubly ionized oxygen. I had hoped that perhaps there was a spectral reason to what I viewed year after year – but still no answer. Like all amateurs, I became the victim of “aperture fever” and I continued to study M27 with a 12″ telescope, never realizing the answer was right there – I just hadn’t powered up enough.

Several years later while studying at the Observatory, I was viewing through a friend’s identical 12″ telescope and, as chance would have it, he was using about twice the magnification that I normally used on the “Dumbbell.” Imagine my total astonishment as I realized for the very first time that the faint central star had an even fainter companion that made it seem to wink! At smaller apertures or low power, this was not revealed. Still, the eye could “see” a movement within the nebula – the central, radiating star and its companion. Do not sell the Dumbbell short. It can be seen as a small, unresolved area in common binoculars, easily picked out with larger binoculars as an irregular planetary nebula, and turns astounding with even the smallest of telescopes. In the words of Burnham, “The observer who spends a few moments in quiet contemplation of this nebula will be made aware of direct contact with cosmic things; even the radiation reaching us from the celestial depths is of a type unknown on Earth…”

Ready for a galactic star cluster for both binoculars and a small telescope? The return to Alpha and begin about two fingerwidths southeast and right on the galactic equator you’ll find NGC 6823 (RA 19 : 43.1 Dec +23 : 18). The first thing you will note is a fairly large, somewhat concentrated magnitude 7 open cluster. Resolved in larger telescopes, the viewer may note these stars are the hot, blue/white variety. For good reason. NGC 6823 only formed about 2 billion years ago. Although it is some 6000 light-years away and occupies around 50 light-years of space, it’s sharing the field with something more – a very large emission/reflection nebula, NGC 6820. In the outer reaches of the star cluster, new stars are being formed in masses of gas and dust as hot radiation is shed from the brightest of the stellar members of this pair. Fueled by emission, NGC 6820 isn’t always an easy visual object – it is faint and covers almost four times as much area as the cluster. But trace the edges very carefully, since the borders are much more illuminated than the region of the central cluster. Take the time to really observe this one! Its processes are very much like those of the “Trapezium” area in the Orion nebula. Be sure to mark your observing notes. NGC 6823 is Herschel VII.18 and NGC 6820 is also known as Marth 401!

If you’d like to try something new, return to M27 and head 2 degrees west-northwest to find NGC 6830 (RA 19 : 51.0 Dec +23 : 04). This rich 7.9 magnitude, cross-shaped open cluster is a real treat. Continue another 2 degrees in the same direction to pick up 7.1 magnitude cluster NGC 6823. Those with large telescopes should look for a faint sheen of nebulosity associated with this youthful open cluster!

Now let’s work on a pair of open star clusters for both binoculars and small telescopes, starting with NGC 6885 (RA 20 : 12.0 Dec +26 : 29). This little 6th magnitude sparkle of stars includes that bright O class star you can see visually and is also known as Caldwell 37. In binoculars you’ll see another compression nearby listed as NGC 6882 (RA 20 : 11.7 Dec +26 : 33). While it doesn’t contain a bright and splashy star like its neighbor, NGC 6882 is a nice ring shaped collection!

Our last official target in Vulpecula is superb galactic star cluster NGC 6940 (RA 20 : 34.6 Dec +28 : 18). This 6th magnitude, 31 arc minute cloud of stars is sure to please anyone with any size binoculars or telescope. The more aperture you have – the more stars you resolve! Discovered by Sir William Herschel in 1784 and logged as H VIII.23, this intermediate-aged galactic cluster will blow your mind in large aperture. Although visible in binoculars, as aperture increases the field explodes into about 100 stars in a highly compressed, rich cloud. Although not visited often, NGC 6940 is on many observing challenge lists. Use low power to get the full effect of this stunning starfield!

While NGC 6834 (RA 19 : 52.2 Dec +29 : 25) is officially listed as Cygnus, why not visit anyway? You’re in the neighborhood! It’s a very rich and compact small star cluster that’s a worthy challenge to pick out of the Milky Way star field in a telescope!

Sources:
Wikipedia
SEDS
Chart Courtesy of Your Sky.

February 2, 2009December 24, 2015 by Ian O'Neill

More Faults Found in LHC, But No Further Delay to Start-up

The LHC repairs are progressing well (CERN)

[/caption]In September 2008, the Large Hadron Collider (LHC) suffered a catastrophic quench, triggered by a faulty connection in the electronics connecting two of the supercooled magnets between Sections 3 and 4 of the 27 km-circumference particle accelerator. The “S34-incident” caused tonnes of helium coolant to explosively leak into the LHC tunnel, ripping the heavy electromagnets from their concrete mounts.

Naturally, this was a huge blow for CERN, delaying the first particle collisions by several months. However, the repair work is progressing well, and hopes are high for commencement of LHC science as early as this summer. Now engineers are working hard to avoid a recurrence of the S34 Incident, tracking down similar electrical faults between the accelerator magnets. It seems like they have found many more faults than expected…

According to a recently published progress report, the LHC repairs are progressing as planned, but more electrical faults have been discovered in other sections of the accelerator. An electrical short has been blamed for the quench four months ago, only weeks after the first circulation of protons around the LHC in the beginning of September 2008. It is now of paramount importance to isolate any further potential shorts in the complex experiment. It would appear engineers are doing a good job in tracking them down.

Ribbons of superconducting niobium-titanium wire is used by the LHC to carry thousands of amps of current to the magnets. Connecting the ribbon from electromagnet-to-electromagnet are splices that are soldered in place. Should one of these splices be weakened by poor soldering, an electrical short can occur, making the magnets lose superconductivity, initiating a quench, rapidly heating the sensitive equipment. Various sections are being re-examined and re-soldered. The good news is that this additional work is not compounding the delay any further.

It has been confirmed that there was a lack of solder on the splice joint. Each sector has more than 2500 splices and a single defective splice can now be identified in situ when the sector is cold. Using this method another magnet showing a similar defect has been identified in sector 6-7. This sector will be warmed and the magnet removed. The warm up of this additional sector can be performed in the shadow of the repair to sector 3-4 and will therefore not add any additional delay to the restart schedule. — CERN

Hopefully we’ll see a second circulation of protons this summer, and according to informal rumours from a contact involved in the LHC science, the first particle collisions could start as early as October 2009. I will listen out for any further official confirmation of this information…

Sources: CERN, Nature.com

February 2, 2009December 24, 2015 by Nancy Atkinson

Cassini Will Switch to Back-up Thrusters

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In a move reminiscent of Star Trek’s Scotty fine-tuning the Enterprise’s performance, engineers working with the Cassini spacecraft will begin work to switch the spacecraft’s thrusters to a back-up set after noticing a degradation in performance from the main thrusters that have been in use for over 11 years, since the spacecraft launched in October of 1997. The thrusters are used for making small corrections to the spacecraft’s course and for attitude control. In mid-March, the current set of eight thrusters, referred to as branch A, will be swapped over to a redundant and identical set, branch B. In a forward thinking move, almost all Cassini engineering subsystems have redundant backup capability. And in a testament of the spacecraft’s robustness and reliability, this is only the second time during Cassini’s 11-year flight that the engineering teams have gone to a backup system.

“Ay, Captain. Auxiliary thrusters engaged!”

Cassini’s propulsion engineers began to see a lower performance from one of the thrusters on branch A in October, and recently a second branch A thruster also began now showing some degraded performance.

An extensive review with the propulsion system contractor, Lockheed Martin Space Systems, Denver, Colo., the thruster manufacturer, Aerojet, Sacramento, Calif., and propulsion experts at NASA’s Jet Propulsion Laboratory, Pasadena, Calif., was completed last week. The recommendation was made to swap to side B as soon as is practical.

Nine of Saturn's moons are in this image. Can you find them? Credit: NASA/JPL/Space Science Institute

Mid-March is the earliest practical opportunity to make the swap. This allows time for the team to properly test and prepare the sequence of commands that will be sent to the spacecraft. Science planners have identified a period where no high-priority science will be lost during the switch, which will be done over a seven-day window. It also is a time when no navigation maneuvers are required to maintain the spacecraft’s trajectory.

The swap involves commanding a latch valve to open hydrazine flow to the B side, and powering on some thruster control electronics. No pyrotechnic devices are involved in the swap, and the action is fully reversible if necessary.

A few years ago, the backup reaction wheel was brought online and is currently functioning as one of the three prime wheels.

Cassini successfully completed its four-year planned tour and is now in its “Equinox” extended mission operations.

Source: JPL

February 2, 2009December 24, 2015 by Nancy Atkinson

Google Oceans, Google Mars

The Mars feature of Google Earth 5.0 lets users see the Red Planet from the perspective of Rovers like the NASA Mars Pathfinder Rover. (Credit: NASA/Google/JPL/University of Arizona)

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Google Earth now allows you to probe the depths of Earth’s oceans as well as fly through the giant canyons or volcanoes on Mars. Google Earth 5.0 was unveiled today, with substantial upgrades for both the Earth and the Red Planet. Google worked in conjunction with NOAA and NASA to incorporate data from our undersea explorations and the spacecraft orbiting Mars. For the first time, you’ll be able to look at the two-thirds of our planet covered by the oceans, take a tour below sea level, and even look at historical imagery to see things like coastal erosion. On Mars there’s a rich conglomeration of images, including the most recent from the Mars Reconnaissance Orbiter to provide an immersive 3D view of Mars. Marine scientists say the electronic images will boost awareness and increase public support for marine conservation, while NASA says the new features in Google Mars will aid public understanding of Mars science, while also providing researchers a platform for sharing data similar to what Google Earth provides for Earth scientists.

In Google Oceans, you can click a function called Touring and you can create narrated, illustrated tours, on land or above and below the sea surface, describing and showing things like a hike or scuba excursion, or even a research cruise on a deep-diving submarine.

A view of the coast of Maui, outside Lanai City, Hawaii, from the new version of Google Earth.

By choosing among 20 buttons holding archives of information, called “layers” by Google, a visitor can read logs of oceanographic expeditions, see old film clips from the heyday of Jacques-Yves Cousteau and check daily Navy maps of sea temperatures.

While only 5% of the ocean floor is mapped in detail, the replicated seas have detailed topography reflecting what is known about the abyss and continental shelves with rougher areas where little is known.

On Mars, you can enjoy a high-resolution, three-dimensional view of the Red Planet.

There is a mode that enables users to fly virtually through enormous canyons and scale huge mountains on Mars that are much larger than any found on Earth. Users also can explore the Red Planet through the eyes of the Mars rovers and other Mars missions, providing a unique perspective of the entire planet.

Clickable links allow you to learn about new discoveries and explore indexes of available Mars imagery. If you’re into working with the raw images from the Mars rovers or orbiting spacecraft, the new Mars mode also allows users to add their own 3D content to the Mars map to share with the world.

Since 2005, Google Earth has been downloaded on half a billion computers, and visitors spend one million hours a day perusing Google Earth and the related Google Maps.

Guess what I’ll be doing the next few hours!

Download Google Earth 5.0.

Sources: NASA, New York Times

February 2, 2009December 24, 2015 by Tammy Plotner

Volans

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The southern circumpolar constellation of Volans was first introduced in 1589 by Petrus Plancius on a celestial globe which was later added to Johann Bayer’s atlas – Uranometria – in 1603. Volans spans 141 square degrees of sky, ranking 76th in size. It has 6 mains stars in its asterism and 12 Bayer Flamsteed designated stars within its confines. Volans is bordered by the constellation of Carina, Pictor, Dorado, Mensa and Chamaeleon and is best seen at culmination during the month of March.

Since Volans is considered a “new” constellation, it has no mythology associated with it – only what the constellation is meant to represent. The constellation of Volans was originally created by Petrus Plancius from the stellar observations of Dutch sea navigators Pieter Dirkszoon Keyser and Frederick de Houtman when exploring the southern hemisphere. Volans’ stellar patterns became known when it appeared on a celestial globe in 1597 and was considered a constellation when it was added to Johann Bayer’s Uranometria catalog in 1603 and it was then called Piscis Volans – the “Flying Fish”. When it was later adopted as a permanent constellation by the International Astronomical Union, the name was simplified and shortened to just Volans.

Let’s begin our binocular tour of Volans with its Alpha star – the “a” symbol on our chart. Alpha Volantis is located approximately 124 light years from Earth and it is a white class A (A2.5) subgiant star. While it is not anything particularly special, it is about twice the size of our Sun and shines about 30 times brighter. Somehow it got the Alpha designation, even though Beta (the “B” symbol) is physically brighter and 16 light years closer! Want a real trip? Then have a look at Delta – the “8” symbol. Even though it appears almost as bright as the rest of the stars, Delta is an F-type bright giant star that’s 660 light years from our solar system!

Now, get out your telescope for Epsilon Volantis – the backwards “3”. Epsilon is a triple star system! Located approximately 642 light years from Earth, the primary component, Epsilon Volantis A, is a spectroscopic binary star all of its own. It’s a blue-white B-type subgiant star with a companion that orbits so close we can only see it spectroscopically and know that it causes changes about every two weeks. But take a close look and you’ll discover a third, 8th magnitude star there, too. Epsilon Volantis B is 6.05 arcseconds away and an easy capture for a small telescope and large binoculars.

How about Gamma Volantis? It’s the “Y” symbol. This wide double star was just meant for binoculars! The two members are brighter, western Gamma-1 Volantis (magnitude 5.67) and dimmer, eastern Gamma-2 (magnitude 3.78). Set apart by 14.1 seconds of arc, you won’t have any trouble cutting these two stars apart and their color contrast make them a real winner in a telescope. Gamma-2 is a standard orange class K (K0) giant star and Gamma-1 is a a white class F (F2) dwarf star. While you might think this is an optical double star, it isn’t. The pair is physically bound to each other and both stars are about 142 light years away.

For those wishing a challenge, take on about the only deep sky study to be found in Volans – NGC 2442 (RA 7 : 36.4 Dec -69 : 32). At 11th magnitude and 6 arc minutes in size, this low surface brightness barred spiral galaxy is a nice study for a large telescope. Located about 50 million light years away from our Milky Way Galaxy, NGC 2442 was first was discovered by Sir John Herschel and contains a very unusual dark cloud of gas – one devoid of any stars. How did this come to be? Astronomers believe the cloud was torn loose from NGC 2442 by a companion during a galaxy interaction. Why not? After all, NGC is surrounded! If you have large aperture, you’ll see PGC 21457, PGC 21406, NGC 2434, PGC 21212, PGC 21323, PGC 21369 and PGC 21426 are nearby, too. Several of these satellite galaxies are physically related to NGC 2442. Be sure to look for two spiral arms extending from a pronounced central bar, giving the whole galaxy a hook-shaped appearance.

Sources:
Wikipedia
University of Wisconsin
Chart Courtesy of Your Sky.

February 2, 2009December 24, 2015 by Tammy Plotner

Journey Inside A Bok Globule

NGC281/IC1590 Parallel Vision - Jukka Metsavainio

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You asked for more? You got it. This time our dimensional visualization is going to take us 9500 light years away from where you’re sitting now and deep into the Perseus spiral arm of the Milky Way Galaxy. Buckle your seat belt and relax your eyes, because we’re heading into two versions of a 132 light year expanse known as NGC 281 and the central core called IC 1590…

Just like last time, this dual image requires a little bit of a challenge on your part to create a 3D effect. Thanks to the wizardry of Jukka Metsavainio, we’ve gone even one better. There’s two! The first version you see on this page are for those of you who have success relaxing your eyes and being a certain distance from the screen to get the images to merge. The one below is for those of you who have better luck crossing your eyes and catching dimension in the center image. Are you ready for your journey? Then have a look and let’s learn…

NGC281/IC1590 Hubble Heritage Cross Vision - Jukka Metsavainio

The whole gigantic region of nebulosity is known as NGC 281 and most commonly referred to as the “Pac Man Nebula”. Visible to small telescopes and located in the constellation of Cassiopeia (RA 00:42:59.35 Dec +56:37.18.8), this cloud of high density hydrogen gas is being ionized by an incredible output of ultraviolet radiation from the hot, neophyte stars which coalesced there. Deep in the center of this HII region is a open area called IC 1590 – home to a young galactic star cluster – and several dark patches known as “Bok Globules”.

If that sounds like something you might expel when you have a cold, you’re right. They are cold… Cold pockets of dense dust, molecular hydrogen and gas. Bok globules are the brain child of astronomer Dr. Bart Jan Bok – who, among other things, loved to study the paranormal. When Bok proposed their existence in the 1940’s, he knew what was going on. These dark regions were acting like interstellar cocoons – protecting their inner stars from being stripped by the radioactive stellar winds of nearby companions and blocking visible light. When stellar metamorphosis had occurred, the new star then begins to send out its own winds and radiation to evaporate the globule – but this isn’t always the case. Sometimes the cocoon gets destroyed before the life inside ignites.

In our image you will see bright blue stars, members of the young open cluster IC 1590, near the globules. Meanwhile, the cluster’s partially revealed core in the upper right hand corner is filled with a tight grouping of extremely hot, massive stars emitting visible and ultraviolet light, causing those incredible pink clouds. When these star forming dust clouds were first imaged by Hubble, we thought we knew a lot about them. But what have we learned since?

According to research done by T.H. Henning (et al): “The exciting star HD 5005 of the optical nebulosity is a Trapezium system… and emission shows that the molecular cloud NGC 281 A consists of two cloud fragments. The western fragment is more compact and massive than the eastern fragment and contains an NH3 core. This core is associated with the IRAS source 00494+5617, an H2O maser, and 1.3 millimeter dust continuum radiation. Both cloud fragments contain altogether 22 IRAS point sources which mostly share the properties of young stellar objects. The maxima of the 60 and 100 micrometers HIRES maps correspond to the maxima of the (12)CO (3 to 2) emission. The NGC 281 A region shares many properties with the Orion Trapezium-BN/KL region the main differences being a larger separation between the cluster centroid and the new site of star formation as well as a lower mass and luminosity of the molecular cloud and the infrared cluster.”

Great! It’s confirmed! It’s a star forming region, very much like what we can observe when we see M42. But, maybe… Maybe there’s just a little bit more to it than that? Hubble observations shows the jagged structure of the dust clouds as if they are being stripped apart from the outside. What could have caused that? Only the radiation from the nearby stars? Hmmm…. Not everyone seems to think so.

A 2007 study done by Mayumi Sato (et al) states: “Our new results provide the most direct evidence that the gas in the NGC 281 region was blown out from the Galactic plane, most likely in a superbubble driven by multiple or sequential supernova explosions in the Galactic plane.” Supernova? Yeah, you bet. And someone else thinks so, too…

Says S.T. Megeath (et al): “We suggest that the ring has formed in a superbubble blowout driven by OB stars in the plane of the Galaxy. Within the cloud complex, combined optical, NIR, mm and cm data detailing the interaction of a young O star with neighboring molecular cores, provide evidence of triggered star formation inside the cloud complex on a few parsec scale. These data suggest that two modes of triggered star formation are operating in the NGC 281 complex – the initial supernovae triggered formation of the entire complex and, after the first generation of O stars formed, the subsequent triggering of star formation by photoevaporation-driven molecular core compression.”

You’ve got it. This type of research suggests the cores were created within the molecular cloud. When they were exposed to direct UV radiation, the low density gas was stripped. This increase in pressure then caused a rippling shockwave which triggered star formation – first in the compressed regions and then in the HII areas. Says Megeath, “The total kinetic energy of the ring requires the energy of multiple supernovae. Both the high Galactic latitude and large expansion velocity may be explained if the NGC 281 complex originated in the blowout of an expanding superbubble. The loop of HI seen extending from the Galactic plane may trace the edge of a superbubble powered by supernovae near the Galactic plane. The expansion of a superbubble into the increasingly rarefied Galactic atmosphere can lead to a runaway expansion of the shell and the blowout of the bubble into the Galactic atmosphere. NGC 281 could have formed in the gas swept up and compressed in a blowout. Hence, NGC 281 maybe an example of the supernovae-driven formation of molecular clouds (and consequently, supernovae-triggered star formation).”

What incredible region! Hope you enjoyed your journey… And be sure to tip your hat to Bart Jan Bok who told the IAU (when they named Asteroid Bok for him in 1983) “Thanks for a little plot of land that I can retire to and live on.”

Our many, many thanks to Jukka Metsavainio of Northern Galactic for creating this unique image for Universe Today Readers! We look forward to more…

February 2, 2009February 2, 2009 by Nancy Atkinson

Super Bowl Goes to Space

I admit, I watched the Super Bowl with all its hype and consumerism. But who can pass up a good excuse for a party or miss a chance to see Springsteen? A couple of the advertisements caught my eye. One was a fun spot with astronauts tearing around on Titan with a space-age hot rod. The premise is old, but enjoyable nonetheless. If you didn’t get a chance to see it, here it is:

Also, a trailer for the new Star Trek movie aired during the game, with more hot rods:
Continue reading “Super Bowl Goes to Space”

February 1, 2009December 24, 2015 by Tammy Plotner

Comet C/2007 N3 Lulin – A Twist In The Tail

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When Chi-Sheng Lin of Taiwan’s Institute of Astronomy captured three images on July 11, 2007 with something strange in them, it was first believed he’d picked up just another asteroid. But, by July 17 astronomers in Table Mountain Observatory, California were noticing a coma 2-3″ across, with a bright central core. That’s not an asteroid… That’s a comet! And now it’s a comet that’s doing something very strange…

By the end of 2008, Comet C/2007 N3 Lulin had steadily began to brighten and now is within easy reach of binoculars for all observers. How bright is it? At last estimate it is between magnitude 6 and 7. That means just a little too faint to be seen unaided, but bright enough to be spotted easily with just the slightest of visual aids. Our own Nancy A. did an article on this not long ago!

But there’s something going on with N3 Lulin, right now… Something very different. There’s a twist in the tail! Check this out…

Comet C/2007 N3 Lulin (negative luminance) - J. Brimacombe

While imaging N3 Lulin for UT Readers, Dr. Joe Brimacombe used a negative luminance frame to take a closer look at what’s going on and discovered something quite out of the ordinary. First off, you’ll notice an anti-tail – quite rare in itself – but if you take a look about halfway down the ion/dust tail, you’ll see a very definite twist in the structure. It it rotating? Exactly what’s causing it? Torsional stress? Is it possible that the kink in the tail is an instability resulting from currents flowing along the tail axis? Right now there’s absolutely no information available about what’s going on in the tail – because what you’re seeing is perhaps one of the most current pictures of the comet that can be found!

If you’re interested in viewing Comet C/2007 N3 Lulin for yourself and would like some help locating it, there’s a wonderful resource that’s easy to use. Just go to Chris Peet’s Heaven’s Above website and make use of the tools there. It will give you easy to follow charts and all you need is just a pair of binoculars to spot this comet for yourself. Don’t sit inside… Do it!

My sincere thanks to Dr. Joseph Brimacombe of Northern Galactic for not only his superb imaging – but his sublime sense of curiosity which caught this anomaly!