A composite illustration of the AGILE satellite and the Crab Nebula imaged by the Chandra observatory. [Image courtesy of ASI, INAF and NASA]
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The Crab Nebula is one of the most popular targets for astronomers of all stripes. It is readily viewable in moderate sized amateur telescopes and wows new viewers at star parties when they’re informed they’re looking at the remnant of a supernova that exploded in 1054 AD. The nebula is also a popular target for professional astronomers looking to study physics in the environment of a pulsar. Powered by synchrotron radiation from the pulsar, the nebula glows brightly across numerous wavelengths in a steady manner that is so consistent, that astronomers have used it to calibrate instruments in different portions of the spectrum. The largest regular variation discovered was a mere 3.5% in the X-ray portion of the spectrum.
But on September 22 of 2010, the Italian Space Agency’s AGILE satellite observed a sudden brightening in the nebula in the gamma ray portion of the spectrum. The Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope, which observes the Crab regularly, confirmed this flaring. Strangely, telescopes observing the nebula in other spectral regimes showed no brightening at all. The lone exception was a small knot roughly one arcsecond in diameter seen by the Chandra X-ray telescope which is believed to correspond to the base of a jet emanating from the pulsar.
Many telescopes observed the central pulsar in X-rays as well as radio to attempt to discover if there had been a sudden change in the power source itself that caused the sudden brightening, but no changes were apparent. This suggests that the flare didn’t come directly from the pulsar, but rather from the nebula itself, perhaps as an interaction between the jet and the magnetic field of the nebula causing intense synchrotron radiation. If this is the cause, then the energy of the accelerated electrons is among the highest of any astronomical event. Such a case is of interest to astronomers and physicists because it provides a rare test bed into relativistic physics and particle acceleration theory.
While this event was certainly noteworthy, it was not entirely unique. AGILE detected a previous flare on October 7, 2007 and Fermi’s LAT had discovered another in February 2009. Currently, none of these events have been entirely explained but will likely give astronomers a target for future studies. Based on the amount of coverage the Crab Nebula receives from telescopes, astronomers are no expecting that such flares are a relatively common occurrence, happening about once a year. If so, this will provide an excellent opportunity to study such events with more scrutiny.
Dusty debris around an old white dwarf star (NASA)
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The primary method by which astronomers hope to study exoplanet atmospheres is by detecting their absorption spectra as they transit their parent stars. However, another way would be to detect the signal of the atmospheric components in the atmosphere of a star that recently cannibalized a planet or other large body. White dwarfs offer an excellent class of stars on which to use this method since convection will pull heavy elements down more rapidly, leaving surfaces with near pristine hydrogen and helium photospheres. The presence of other elements would indicate recent accretion. This method has been used on several white dwarfs previously, but a new study reexamines data from a 2008 paper, adding their own data on the white dwarf GD61 to propose that the star isn’t just eating dust and small bodies, but a sizable one, likely containing water.
Data for the project were taken in 2009 using the SPITZER telescope. One of the first clues to the presence of a recent case of cannibalism was the presence of warm dust within the Roche limit of the star. This disc did not extend more than 26 stellar radii from the star, leading the team to suspect that this was not simply a large scale disc feeding the star with rocky materials, but an object that had fallen inwards to be tidally torn apart.
To support this, the new team used the Keck I telescope on Mauna Kea with the HIRES spectograph to analyze the spectrum. The findings from this confirmed the previous study that, in order of decreasing abundance, the star contained helium, hydrogen, oxygen, silicon, and iron. Based on the amount of material present in the spectrum and estimated convection rates for such stars, the team concluded that, if the disc were created by a single body, it would have been an asteroid at least 100 km in diameter. So why should the team expect that it was a single body as opposed to many smaller ones?
The key lies in the relative amount of detected elements. For GD61, oxygen was the most abundant element not typically present in white dwarf atmospheres. In fact, its presence far outweighed the other elements such that, even if all of it had been previously bound to the silicon, iron, carbon, and other trace elements, there would still be an inexplicable excess. This oxygen would necessarily have been combined into some molecule or have dissipated during the red giant phase. The only way the team could account for its presence would be to have it wrapped up in water (H2O) which, after disassociation, would allow the hydrogen to blend in the the expected hydrogen already present. Since water readily sublimates without sufficient pressures, the team notes that a large number of small bodies would be unable to bury the water deep enough to keep it from escaping previously, that the best explanation would be a large body which could shield water inside it during the previous red giant phase.
The evidence of water rich asteroids speaks to the formation of our own solar system because it provides a delivery mechanism for water to our planet beyond direct accretion. Water rich asteroids and comets would likely have supplemented our supply. Indeed, Ceres, the largest known asteroid in our solar system, is suspected to harbor as much as 25% of its mass in water.
A new infrared view of the star formation region Messier 8, often called the Lagoon Nebula, captured by the VISTA telescope at ESO’s Paranal Observatory in Chile. Credit: ESO/VVV
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This rich and stunning new infrared view of the Lagoon Nebula shows detail never seen before. Doesn’t it make you want to dive in for a closer look? Well, you can do just in that in a video below that zooms in on all the detail. The image was captured as part of a five-year study of the Milky Way using ESO’s VISTA telescope at the Paranal Observatory in Chile. This is a small piece of a much larger image of the region surrounding the nebula, which is, in turn, only one part of a huge survey.
The survey is called VISTA Variables in the Via Lactea (VVV), and with ESO’s Visible and Infrared Survey Telescope for Astronomy (VISTA), astronomers can scour the Milky Way’s central regions for variable objects and map its structure in greater detail than ever before.
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This image of the Lagoon Nebula (also known as Messier 8,) is part of that survey. The region which lies about 4000–5000 light-years away in the constellation of Sagittarius (the Archer).
Infrared observations allow astronomers to peer behind the veil of dust that prevents them from seeing celestial objects in visible light.
Stars typically form in large molecular clouds of gas and dust, which collapse under their own weight. The Lagoon Nebula, however, is also home to a number of much more compact regions of collapsing gas and dust, called Bok globules. These dark clouds are so dense that, even in the infrared, they can block the starlight from background stars. But the most famous dark feature in the nebula, for which it is named, is the lagoon-shaped dust lane that winds its way through the glowing cloud of gas.
Hot, young stars, which give off intense ultraviolet light, are responsible for making the nebula glow brightly. But the Lagoon Nebula is also home to much younger stellar infants. Newborn stars have been detected in the nebula that are so young that they are still surrounded by their natal accretion discs. Such new born stars occasionally eject jets of matter from their poles. When this ejected material ploughs into the surrounding gas short-lived bright streaks called Herbig–Haro objects are formed, making the new-borns easy to spot. In the last five years, several Herbig–Haro objects have been detected in the Lagoon Nebula, so the baby boom is clearly still in progress here.
Amazing Swedish view of Jan 4, 2011 partial solar eclipse, which reached its maximum – about 85%- in this stunner from Stockholm, Sweden. Poor weather and obscuring clouds momentarily relented at just the perfect time. Credit: Peter Rosen
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Millions across Earth enjoyed one of nature’s most awesomely spectacular events during today’s (Jan. 4) partial solar eclipse – the first of four set to occur in 2011. And there was nothing partial about it, for those lucky eyewitnesses where it was visible in parts of Europe, Africa and Central Asia. The eclipse reached its maximum, about 85%, in Sweden. See the maximum stunner above – taken despite pessimistic weather forecasts -by Peter Rosen in Stockholm, Sweden, with more photos from the sequence here at spaceweather.com
Probably the most technically amazing feat is the double solar eclipse captured in one image by renowned astrophotographer Theirry Legault – see below – boasting both the ISS and the Moon on the eclipsed sun’s face. Legault had traveled to the deserts of the Sultanate of Oman, near to the capital of Muscat, for this rare spectacle of nature. The ISS was calculated to be visible in a thin strip barely 11 kilometers wide, according to Astronomie Info news. The ISS transit lasted just about 1 second, speeding by at 28,000 km/sec.
See a global compilation of gorgeous eclipse photos here and comment or send us more. Update 1/6/11: this is a work in progress so please check back again.
New readers photos and eyewitness accounts added below today; as received
Click to enlarge all photos
First up: Double Solar Eclipse by renowned astrophotographer Theirry Legault in Oman
Amazing Double Solar Eclipse with the ISS and the Moon captured in one image in the deserts of the Sultanate of Oman. Credit: Theirry Legault
Check out this exciting gallery of images contributed by eclipse watchers from multiple locations around the world, on Flickr
Composition of 8 different exposures between 8.10 and 9.18 (local) recorded with solar filter and added to a unfiltered picture at the beginning of sequence. Taken with a Sony DSCW-1 with 35mm equivalent focal length. Credit: Marco Di Lorenzo, Pescara, Italy
Here is a collection of images and an eyewitness report sent to me by Marco Di Lorenzo, in Pescara, Italy
Filtered and unfiltered views at 9.11 local time. Credit: Marco Di Lorenzo
Marco writes; Pescara is located at 42.467°N and 14.225°E, about in the center of Italy on the Adriatic sea. I chose my location at the new pedestrian bridge because it is a modern structure which offers a nice foreground and also an open, elevated viewpoint. I used a couple of cameras plus a digital video camera. All the cameras were mounted on a tripod.
The weather was cold and the situation didn’t improve in the mid morning. Illumination was comparable to a slightly foggy day. The frigid temperature didn’t encourage people to go out and check. However some people did venture out. Someone asked me some info on eclipses and how to take pictures of it – very hard indeed, especially if you use a cellular phone ! Combo of 2 pictures taken few seconds apart using solar filter and different exposure; local time was 9.11 AM, near maximum. Marco Di Lorenzo
Urijian Poernick sent these photos and description:
“Colorful Solar Eclipse” at Halley Astronomical Observatory, Heesch, The Netherlands Partial Solar eclipse and flock of birds from Heesch, The Netherlands. Credit: Urijian Poernick
The weather forecast predicted overcast skies with only a few small bright intervals in all parts of The Netherlands. Nevertheless, dozens of members of Halley Astronomical Society and visitors, including many children, challenged the cold winter weather and came together on the flat roof of Halley Astronomical Observatory in The Netherlands.
Partial Solar eclipse from Heesch, The Netherlands. Credit: Urijian PoernickAfter sunrise at 7:44 UT (8:44 local time) they all looked at a narrow opening in the cloud deck near the eastern horizon. At 8:00 UT the sun showed itself: first we saw the left horn of the eclipse and a few moments later the right one.
Due to the clouds and veils it was a very colorful eclipse, with all tints of red and yellow. After twenty minutes the sun and the moon disappeared behind the overcast skies again and they didn’t come back before the end of the eclipse (9:39 UT).
During this short period everyone could watch the eclipse through the telescope and we were all enthusiastic. It was a beautiful spectacle! www.sterrenwachthalley.nl
Gianluca Masi is the National Coordinator of Astronomers Without Borders in Italy and captured this pair of photos from partially overcast Rome, Italy. The clouds contributed to make for a delightfully smoky eclipsed sun Smoky eclipsed sun from Rome, Italy. Credit: Gianluca Masi Credit: Gianluca Masi
Edwin van Schijndel sent me this report from the Netherlands:
I made some pictures in the southwest of the Netherlands. The weather conditions were not so good in the early morning, most places were covered by clouds so we decided to move about 70 miles to the southwest from our hometown. Finally we stopped not far from the city of Bergen op Zoom and were able to see sunrise while most of the sun was covered. It was splendid!
Eclipsed sunrise from Bergen op Zoom, the Netherlands. Credit: Edwin van Schijndel
Unfortunately there came more clouds so the rising sun disappeared and we drove 20 miles to the north just before Rotterdam and the sky was more clear at this place. Again we took some pictures but the maximum covering of the sun had been a few minutes before. After all this wasn’t really a pity, we were very lucky to have seen the rising of the sun and be able to make some nice pictures of the partial eclipse. Many people in the Netherlands saw less or even nothing.
Credit: Edwin van Schijndel Credit: Edwin van Schijndel
Send us or comment more solar eclipse photos to post here. ken : [kremerken at yahoo.com]
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More Readers Photos and Eyewitness Accounts. Beautiful, Thanks ! ken
Story and Photos sent me by Stefano De Rosa. Turin, Italy
Early in the morning, I moved to a site close to Turin (Italy) where the forecast was not so bad as in my city to try to observe and photograph the partial solar eclipse. Unfortunately, when I arrived it was cloudy and foggy and so decided to go back home. Technical details: Canon Eos 1000d, F/22; 150-500mm lens @ 500mm; ISO. 1/1600 sec Turin, Italy. Credit: Stefano De Rosa
Suddenly, as I was sadly driving on the motorway, close to the city of Alessandria, noticed a little break on the clouds from my rearview mirror: I stopped the car and, after a quick set up, managed to capture the crescent Sun!
http://ofpink.wordpress.com Well, I hope you carefully looked back before hitting the brakes ! – ken Turin, Italy. Credit: Stefano De Rosa
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Story and Photos sent me by Roy Keeris, Zeist, The Netherlands
Middelkerke, The Netherlands. Credit: Roy Keeris
Me and a friend (Casper ter Kuile) wanted to see the eclipse from The Netherlands. If clouds should intervene, we planned to drive a little (max. a couple of hours) to a place with a better chance for a clear sky. During the night we checked weather forecasts and satellite images. We were pretty unsure if we would succeed in seeing the eclipse, because it was pretty cloudy, and especially the low clouds tend to be quite unpredictable. In the end we chose to drive to Middelkerke (near Oostende) in Belgium because of a clear spot approaching from the North Sea.
Middelkerke, The Netherlands. Credit: Roy Keeris
We arrived at the Belgian coast just in time before sunrise. There we witnessed the eclipse from the top of a dune. About 25 minutes after sunrise the sun appeared from behind the lower clouds, just when the eclipse was at its maximum. It was magical!
First we saw the right ‘horn’ and then the left one appeared. From then on we watched the rest of the eclipse and took many pictures. [no pics from Casper ??]
Later we heard that despite the clouds, many people in The Netherlands were able to see the eclipse. There was a long stretch with a clear zone in the clouds- near the border of Germany.
Middelkerke, The Netherlands. Credit: Roy Keeris
If they had a clear horizon, people could look underneath the clouds and were just able to see the sunrise. I could even have seen it at home from my apartment on the 13th floor! But the trip was fun. It’s always nice to hunt for the right place to be at these events.
Here are some pictures I took from Middelkerke. They were shot with a Canon 400D in combination with a Meade ETS-70 telescope and a Tamron 20-200mm lens.
Thanks – Yes the hunt is half the fun. ken
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Story and Photos sent me by Igal Pat-El, Director, Givatayim Observatory, Tel Aviv, Israel
We took some images of the Jan. 4 Solar Eclipse from the Givatayim Observatory, just near Tel-Aviv, Israel. We were pleased to have Prof. Jay Passachoff as a guest during the eclipse. We had a live broadcast in plan but we had to cancel it due to heavy rain from the first contact, therefore we closed the dome’s shutter and went to the balcony trying to take some quick photos of the eclipse.
Tel Aviv, Israel. All Photos Credit: Igal Pat-El, Givatayim Observatory.
Collage assembled by Ken Kremer
We had the portable PST Coronado CaK telescope with a Ca filter On a Alt-Az mount (we could not do any alignment due to the rain). We took about 5 images against all odds in this very dim filter, using the Orion SS II Planetary imager, all of them through the haze and clouds.
Thanks, Igal. Another good lesson learned. Take a chance. You never know what you’ll get till you try !
I’ve combined Igal’s photos into a collage for an enhanced view. ken
See more photos and a video in comments section below
Colors are important in astronomy. They can be used to get a quick feel for the temperature of stars, map out hydrogen alpha, or even find oxygen when it gives off a distinctive green glow from the forbidden transistion. Yet thus far, all images of exoplanets have only been taken in a single color filter leaving astronomers with a flat picture and no understanding of the color of a planet. A new paper corrects this oversight while analyzing the polarization of reflected starlight to develop an understanding of the characteristics of the planet’s atmosphere.
One of the properties of light is that it often becomes polarized upon reflection. This allows for polarized sunglasses to effectively reduce glare from road surfaces because the reflection tends to polarize the light in a preferred direction. Similarly, light striking a planet’s atmosphere will have a preferred axis of polarization. The degree of polarization will depend on many factors including, the angle of incidence (corresponding to the planetary phase), the types of molecules in the atmosphere, and the color, or wavelength, of light through which the planet is observed.
The object of interest was HD189733b and observations were taken in using the UBV filters system which uses filters in the ultra-violet, blue, and green (or “visible”) portions of the spectra. They were conduced at the Nordic Optical Telescope in Spain.
To control for the variations, astronomers would need to observe the planet at several wavelengths to understand how the color was affecting the results, as well as to watch the planet for several orbits to trace how the phase impacted the observations. Presently, the authors have not gone so far as to compare various composition models against these observations as this study was largely intended to be a feasibility study at multi-wavelength polarization detection.
Results have shown that the planet is brightest in the blue portion of the spectra, a result that confirms earlier, theoretical predictions for hot Jupiters as well as tentative observational findings based on single color studies done last year. This supports the notion that the dominant mechanism of polarization is Rayleigh scattering in the atmosphere. The result of this is that the planet would likely appear to be a deep blue to the naked eye, much the same way our sky appears blue, but a much more vivid color due to the increased depth to which we would look. The observations also confirmed that polarization was greatest when the planet was near greatest elongation (as far to either side of the star as possible instead of near in front or behind when viewed from Earth) which supports that the polarization is due to scattering in the atmosphere as opposed to the starlight being initially polarized from large starspots.
Certainly, this study has demonstrated the potential for astronomers to begin exploring planetary characteristics with polarization. However, it may be some time before it becomes accepted in general use. While the findings were certainly above the background noise, there existed a significant degree of uncertainty in the measurements resulting from the faint nature of planets. Being a large, hot Jupiter, HD189733b is a strong candidate since it is close to its parent star and thus, receives a large amount of light. Using such methods for other exoplanets, more distant from their parent stars will likely prove an even more daunting task, requiring careful preparation and observations.
The signatures of a bubble collision at various stages in our analysis pipeline. A collision (top left) induces a temperature modulation in the CMB temperature map (top right). The "blob" associated with the collision is identi ed by a large needlet response (bottom left), and the presence of an edge is determined by a large response from the edge detection algorithm (bottom right). (Feeny, et al.)
In the realm of far out ideas in science, the notion of a multiverse is one of the stranger ones. Astronomers and physicists have considered the possibility that our universe may be one of many. The implications of this are somewhat more fuzzy. Nothing in physics prevents the possibilities of outside universes, but neither has it helped to constrain them, leaving scientists free to talk of branes and bubbles. Many of these ideas have been considered untestable, but a paper uploaded to arXiv last month considers the effects of two universes colliding and searches for fingerprints of such a collision of our own universe. Surprisingly, the team reports that they may have detected not one, but four collisional imprints.
Red Moon, Red Mars. Top - Dec 21, 2010 Lunar Eclipse photos of the Red Moon taken near Princeton, NJ on an exquisitely clear night with a 250 mm lens and 1 sec exposure. Credit: Ken Kremer. Bottom Left: Red Mars from the Hubble Space Telescope. Credit: NASA. Right: Red Mars through a telescope in 2010 from The Plantation in Florida (not to scale). Credit: Ernie Rossi
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In this season of Christmas tidings, many of us were blessed to witness the eerie Red Moon of the total lunar eclipse a few nights ago on Dec. 21. Here in “bonechilling” New Jersey, it was miraculously crystal clear the entire night from the beginning around 1:30 a.m. EST to the end – about three and one half hours later at around 5 a.m.
UPDATE: Check out more readers “Red Moon, Red Planet” astropix contributions below !
The eclipse occurred as the moon passed through the Earth’s inner dark shadow, or umbra and changed dramatically to varying shades of red, orange and brown.
Lunar Eclipse 12-21-2010 from The Plantation in Florida. Credit: Ernie RossiDuring totality – when the moon was completely immersed in the umbral shadow for about 72 minutes – the red moon changed from a faint red glow to a brilliant crimson red. At times it appeared to be blood red and as though the surface was stirring and oozing droplets of warm and viscous blood. It was surreal and looked to me as though it had been magically and majestically painted up into the night sky.
Well all this redness hanging in the sky during totality caused me to ponder Mars – the Red Planet – especially with the avalanche of good news streaming back lately.
And the wispy white light at near total eclipse harkened to the Martian polar ice caps.
Mars at Opposition in 2003 from New Jersey. 3.5 in Questar 0.1 seconds. Credit: Robert Vanderbei
Bright red Mars at Opposition in 2003 - The year that Spirit and Opportunity launched.
So please send your telescopic shots and descriptions of the Red Planet and/or the Red Moon and I’ll post them here. Email kremerken at yahoo dot com or post as comments to add here.
Lunar Eclipse from New Jersey 12-21-2010. Credit: Robert Vanderbei
Despite the shadow the moon does not completely disappear. The red moon’s glow was caused by sunlight refracted through the earth’s atmosphere and cast upon the lunar surface. The hue varies depending on a variety of atmospheric conditions and can be intensified by floating clouds of volcanic ash and dust. The recent volcanic eruptions at Mount Merapi in Indonesia in October and at Mount Eyjafjallajökull in Iceland last April sent massive plumes of particles skyward which may have influenced the thrilling event.
Red Moon, Red Planet. One day we’ll journey there and back again.
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Send me your astropix of Red Moon and/or Red Mars to post here:
Check out these gorgeous views of Mars in January 2010 from Efrain Morales Rivera at the Jaicoa Observatory in Aquadilla, Puerto Rico Efrain writes; On this session (01/21/10) on Mars of this years apparition many details could be seen for its size. Image at left at closest to Earth and at the limb (L) Mount Olympus largest volcano in our system, Image at right (01/27/10) closest to the Sun. Credit: Efrain Morales Rivera, Jaicoa Observatory, Aquadilla, Puerto Rico
From Robert Vanderbei of Amateur Astronomers Association Of Princeton in New Jersey; A Lunar Eclipse Montage ! Just ahead of the monster blizzard which struck the northeast Corridor of the US on Dec 26.
Dec. 21, 2010 Lunar Eclipse Montage as imaged from New Jersey. Credit: Robert Vanderbei
Some pictures of the eclipse put together as a composite from beginning to totality by Russell King of Willingboro Astronomical Society, New Jersey.
All pictures were taken with my Canon EOS Digital Rebel XSi from my home in Neptune, New Jersey. I used my Canon 75 to 300MM lens and shot all exposures at 300MM. Camera was set on a fixed photo tripod. The pictures range from 1/2500 second at full moon to 1 second during totality. Images were processed in Photoshop 2 and Ulead. Credit: Russell King. http://www.rddnj.com
Many classes of stars are named for an early, distinguished member of a certain type of stars. For example, Cepheid variables take their namesake from the periodic variable Delta Cephei, first recognized by John Goodricke, although Eta Aquillae, another Cepheid, was recognized as a periodic variable with the same period just before Delta Cephei. Since the time of Goodricke’s discovery, many more classes of objects have been discovered from T Tauri, to W Ursa Majoris, to Delta Scorpii.
But sometimes, stars must wait before more members of their class are discovered. Tau Scorpiiis a massive B0 star and one of the rare high mass stars for which magnetic fields have been measured. To distinguish it even further, studies have shown that its magnetic field is unusually complex, being much more tangled than most stars and not showing distinct dipoles. Additionally, this unusual star has been shown to have weaker stellar winds (and consequently, mass loss rates) than most B0 type stars, as well as spectral features that are simultaneously characteristic of stars on the main sequence and young giants. Meanwhile, the star is believed to be only a few million years old. A first step towards characterizing such odd objects is to find more. Fortunately, astronomers have discovered two more stars similar to Tau Scorpii.
The two new stars, HD 66665 and HD 63425, were first recognized as unusual from their spectra, taken by the Canada-France-Hawaii Telescope. Using these spectra, the team, led by Véronique Petit at West Chester University, recognized that these stars had the same peculiar winds as Tau Scorpii. While Petit’s group could not completely constrain the mass loss rates, they did place an upper limit on both, establishing that they too shared the “weak wind problem” in which the expected mass loss rate for such stars was roughly 20 times higher. This prompted the team to investigate each star for magnetic fields.
Although the team wasn’t able to fully analyze the magnetic fields during their observing run to determine just how unusual they were, the team did establish both stars did have magnetic fields present and that they were similar in strength to that of Tau Scorpii. These two pieces of information has led the team to conclude that HD 66665 and HD 63425, along with Tau Scorpii, constitute a new class of stars. Additional confirmation could come from similar conclusions on the age of the analogues.
Petit’s team doesn’t speculate as to the nature of this emerging class in this paper. However, an earlier work of which Petit was a co-author, examined Tau Scorpii specifically. In it, the team examined whether the unusual field was a “frozen in” fossil from formation, or actively produced by an unusual dynamo inside the star. Fields produced by dynamos require large portions of the interior of the star undergoing convection. Models of massive stars predict that convection is likely to be limited in such stars. Another key component is rotation. Tau Scorpii is an extremely slow rotator, so the team concluded that a dynamo is unlikely in this case. As such, the fossil-field theory was more likely. Further investigation of HD 66665 and HD 63425 will certainly be necessary to further compare these stars to Tau Scorpii.
Looking like a holiday card, this view of the lunar eclipse was taken by Stu Atkinson in the UK
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For the first time in almost four centuries a total lunar eclipse coincided with the solstice – mid-winter for northern hemisphere skywatchers and mid-summer for the southern hemisphere. For those with a clear view of the sky (I was not that lucky!), the entire event was visible from North America, Greenland and Iceland, while western Europe saw the beginning stages before moonset and western Asia got the later stages after moonrise. Australia also saw the late stages of the eclipse.
People with clear skies in the northern hemisphere saw the Moon transformed into a “coppery orb,” as Tony Hoffman from Queens, New York called it (see his image below.) The Moon didn’t disappear completely, as the residual light from its surface is refracted by our atmosphere, resulting in the Moon turning a coppery, red or brown color. The eclipse lasted for about three and a half hours. See some images and videos from around the world, below. Clicking on each image will bring you to the original source.
The Washington Monument is seen as the full moon is shadowed by the Earth during a total lunar eclipse on the arrival of the winter solstice, Tuesday, December 21, 2010 in Washington. From beginning to end, the eclipse lasted about three hours and twenty-eight minutes. Photo Credit: (NASA/Bill Ingalls)A 'Coppery Orb' as seen by Tony Hoffman in Queens, NY. 'Well worth braving the cold and wind to catch,' Tony said, 'Relatively bright totality with Moon beautifully situated by the horns of Taurus.''Even with high cloud, a 7 second exposure brought out the beauty of the eclipsed Moon,' said Mark Zaugg from Calgary, Alberta, Canada.The ruddy totally eclipsed Moon as seen by Nick Bramhill in Aberdeen, UK.The Earth's shadow starts to creep across the Moon in this image by Stu Atkinson near Kendal in the UK
Astronomer Amanda Bauer took this image of the eclipsed Moon from the Harbour Bridge in Sydney, Australia.Efrain Morales from the Jaicoa Observatory in Puerto Rico took this sequence of images. 'The weather was not under under optimum conditions,' he wrote, 'but managed to take this sequence thru the cloud gaps until it finally covered it up.This view of the red Moon was taken by Pete Riesett in Baltmore, Maryland.An animation made from 60 images taken by an all-sky telescope in New MexicoThis image was taken by Jen Scheer (aka @flyingjenny on Twitter) from Merritt Island in Florida.
Former space shuttle technician Jen Scheer (@flyingjenny on Twitter) got up earlier than usual (she takes a daily sunrise picture from around Kennedy Space Center each morning) to capture some great shots of the eclipse. You can see more of her images at her Flickr page.
A total lunar eclipse begins as the full moon is shadowed by the Earth on the arrival of the winter solstice, Tuesday, December 21, 2010 in Arlington, VA. Photo Credit: (NASA/Bill Ingalls)This was taken by Phil Plait, the Bad Astronomer, in Boulder Colorado. 'Deep into totality,' Phil said.
Here’s a video taken from Savannah, Georgia in the US:
And another video from UT frequenter, Brent (aka Hellobozos) from Orlando Florida. He took 6 second avi’s every 5 minutes for 6 hours, from 12:30am to 6am EST:
And one more from Carl Hamilton from Bowie, Maryland:
Lunar eclipse from Fair Lawn. NJ. 'Wish I had a more powerful lens but it was well worth waiting up for,' said Universe Today reader Mary Durante Youtt. Here's one from Lancaster County, Pennsylvania. 'We had to dodge clouds, cold, and wind that jiggled the tripod,' said Beth Katz.The eclipse as seen by photographer John O'Connor near Kennedy Space Center.
This image was taken by photographer John O’Connor, who normally takes images of rockets and spacecraft (see his website NASATech, for amazing virtual tours of spacecraft, launchpads and more). He was up in the middle of the night to take images of space shuttle Discovery’s intended rollback from the launchpad to the Vehicle Assembly Building, but the rollback was delayed because of a technical problem.
“I intended to take a couple of quick shots of totality before heading out but ended up spending 45 minutes shooting the moon, as they say,” John wrote me. “This is my first attempt at astrophotography. I shot it with a 300 mm fixed focal length lens with a doubler on it. With the 1.5 multiplier factor on the 2/3 size sensor, it was about 900 mm focal length. It was 4 second shot at 100 ISO with an f4.5 aperture, as wide as the lens would let me go. Note the smudged stars. Even at a 4 second exposure the Earth’s rotation is evident, blurring, ever-so-slightly, the lunar disk.”
![A composite illustration of the AGILE satellite and the Crab Nebula imaged by the Chandra observatory. [Image courtesy of ASI, INAF and NASA]](https://www.universetoday.com/wp-content/uploads/2011/01/tavani1HR.jpg)
