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December 18, 2006, 5:15 AM CT

Weak Sun Produces Record Solar Outburst

Weak Sun Produces Record Solar Outburst Dale Gary, Solar Physicist
Credit: New Jersey Institute of Technolog
A solar outburst, which can play havoc with global positioning systems and cell phone reception, bombarded Earth, Dec. 6, 2006, with a record amount of radio noise, said solar physicist Dale Gary. Gary, who confirmed the news today, is a professor and chair of the department of physics at New Jersey Institute of Technology (NJIT). "Reports of significant events worldwide are still coming in as late as yesterday afternoon," said Gary. Due to a computer software failure, initial research reports in the U.S. downplayed the outbursts.

"The odd thing about this outburst was that the Sun is supposed to be at the minimum phase of its 11-year cycle," said Gary. "Nevertheless, the disruption lasted more than an hour, produced a record amount of radio noise, and caused massive disruptions of Global Positioning Satellite (GPS) receivers world wide".

Since 1997, Gary has directed Owens Valley Solar Array (OVSA), one of the world's leading research facilities to study the sun's impact upon earth. Using special instruments, Gary and researchers at NJIT's Center for Solar-Terrestial Research study solar outbursts. The National Science Foundation and NASA support the work.

A complex sunspot on the Sun was responsible for the outburst, which occurred Dec. 6, 2006 at 3:45 p.m. EST, said Gary. Before the outburst, the radio output of the Sun in the GPS broadcasting band was 54 on the scale of solar flux units. During the outburst, associated with a large solar flare, the radio noise reached around 1 million solar flux units, according OVSA instruments.........

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December 15, 2006, 4:55 AM CT

Making Dark Matter Visible

Making Dark Matter Visible The processes in the Universe after the Big Bang.
As light travels to us from distant objects its path is bent slightly by the gravitational effects of the things it passes. This effect was first observed in 1919 for the light of distant stars passing close to the surface of the Sun, proving Einstein's theory of gravity to be a better description of reality than Newton's. The bending causes a detectable distortion of the images of distant galaxies analogous to the distortion of a distant scene viewed through a poor window-pane or reflected in a rippled lake. The strength of the distortion can be used to measure the strength of the gravity of the foreground objects and hence their mass. If distortion measurements are available for a sufficiently large number of distant galaxies, these can be combined to make a map of the entire foreground mass.

This technique has already produced precise measurements of the typical mass associated with foreground galaxies, as well as mass maps for a number of individual galaxy clusters. It nevertheless suffers from some fundamental limitations. Even a big telescope in space can only see a limited number of background galaxies, a maximum of about 100,000 in each patch of sky the size of the Full Moon. Measurements of about 200 galaxies must be averaged together to detect the gravitational distortion signal, so the smallest area for which the mass can be imaged is about 0.2% that of the Full Moon. The resulting images are unacceptably blurred and are too grainy for many purposes. For example, only the very largest lumps of matter (the biggest clusters of galaxies) can be spotted in such maps with any confidence. A second problem is that many of the distant galaxies whose distortion is measured lie in front of many of the mass lumps which one would like to map, and so are unaffected by their gravity. To make a sharp image of the mass in a given direction requires more distant sources and requires many more of them. MPA scientists Ben Metcalf and Simon White have shown that radio emission coming to us from the epoch before the galaxies had formed can provide such sources.........

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December 12, 2006, 4:41 AM CT

Moon's Escaping Gasses

Moon's Escaping Gasses Millions of years – not billions
Image: NAS
It was widely believed that earth's moon has seen no widespread volcanic activity for at least the last 3 billion years. Now, a fresh look at existing data points to much more recent release of lunar gasses.

The study, published in the journal Nature by geologists Peter Schulz and Carle Pieters of Brown University and Matthew Staid of the Planetary Science Institute, uses three distinct lines of evidence to support the assertion that volcanic gas has been released from the moon's surface within the last 1 to 10 million years. The researchers focus on a D-shaped area called the Ina structure that was first recognized in images from Apollo missions.

The unusual sharpness of the features first called Schultz's attention to the area. "Something that razor-sharp shouldn't stay around long. It ought to be destroyed within 50 million years," said Schulz. On Earth, wind and water quickly wear down freshly exposed surface features. On the airless moon, constant bombardment with tiny space debris accomplishes a similar result. By comparing the fine-scale surface features within the Ina structure to other areas on the moon with known ages, the team was able to place its age at closer to 2 million years.

The scarcity of asteroid impact craters on the surface within Ina provided a second line of evidence for the feature's relative youth. The researchers identified only two clear impact craters larger than 30 meters on the 8 square kilometers of the structure's floor. This frequency is about the same as at South Ray Crater, near the Apollo 16 landing site. The surface material ejected from South Ray Crater has long been used as a benchmark for dating other features on the moon's surface and most lunar scientists studying these rocks agree on a date of approximately 2 million years, based on cosmic ray exposure.........

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December 10, 2006, 9:24 PM CT

A trip to Asteroid Itokawa

A trip to Asteroid Itokawa The Hayabusa craft heads toward the asteroid Itokawa
Itokawa, a spud-shaped, near-Earth asteroid, consists mainly of the minerals olivine and pyroxene, a mineral composition similar to a class of stony meteorites that have pelted Earth in the past.

This asteroid ingredient list, published in Science, comes courtesy of Hayabusa, the spacecraft launched in 2003 by the Japanese Aerospace Exploration Agency (JAXA). The mission of Hayabusa is to bring back first-ever samples from an asteroid to better understand their role as building blocks of the solar system.

Itokawa, an elongated rocky object nearly as long as five football fields, circles the sun more than 321 million miles away from Earth. Along with a few hundred known asteroids, Itokawa's orbit is close to Earth's orbit and was discovered by the Lincoln Near-Earth Asteroid (LINEAR) program, which detects near-Earth asteroids and provides advance warning if any are bound for Earth. Itokawa doesn't currently pose such a threat, but its close proximity made it a tempting scientific target.

A near-infrared spectrometer aboard Hayabusa helped identify Itokawa's mineralogy, mostly a mixture of the rock-forming minerals olivine and pryroxene, and possibly some plagioclase and metallic iron. But to truly understand what they had, the team turned to Takahiro Hiroi, a Brown University researcher who is expert in determining the composition of asteroids and meteorites, bits of asteroids that have fallen to Earth.........

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December 7, 2006, 4:56 AM CT

For Black Holes Size Does Not Matter

For Black Holes Size Does Not Matter Credit R Hynes
Research by UK astronomers, published recently in Nature (7th December 2006) reveals that the processes at work in black holes of all sizes are the same and that supermassive black holes are simply scaled up versions of small Galactic black holes.

An accreting black hole and a binary star.

Credit: R HynesFor many years astronomers have been trying to understand the similarities between stellar-mass sized Galactic black hole systems and the supermassive black holes in active galactic nuclei (AGN). In particular, do they vary fundamentally in the same way, but perhaps with any characteristic timescales being scaled up in proportion to the mass of the black hole. If so, the researchers proposed, we could determine how AGN should behave on cosmological timescales by studying the brighter and much faster galactic systems.

Professor Ian McHardy, from the University of Southampton, heads up the research team whose findings are published recently (along with colleagues Dr Elmar Koerding, Dr Christian Knigge, Professor Rob Fender and Dr Phil Uttley, currently working at the University of Amsterdam). Their observations were made using data from NASA's Rossi X-ray Timing Explorer and XMM Newton's X-ray Observatory.

Professor McHardy comments, "By studying the way in which the X-ray emission from black hole systems varies, we found that the accretion or 'feeding' process - where the black hole is pulling in material from its surroundings - is the same in black holes of all sizes and that AGN are just scaled-up Galactic black holes. We also found that the way in which the X-ray emission varies is strongly correlated with the width of optical emission lines from black hole systems".........

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December 5, 2006, 8:52 PM CT

Astronomers Study Shape Of Stellar Candles

Astronomers Study Shape Of Stellar Candles Artist's impression of how Type Ia supernovae may look like as revealed by the spectr-polarimetry observations.
Astronomers are reporting remarkable new findings that shed light on a decade-long debate about one kind of supernovae, the explosions that mark a star's final demise: does the star die in a slow burn or with a fast bang" From their observations, the scientists find that the matter ejected by the explosion shows significant peripheral asymmetry but a nearly spherical interior, most likely implying that the explosion finally propagates at supersonic speed.

These results are reported today in Science Express, the online version of the research journal Science, by Lifan Wang, Texas A&M University (USA), and colleagues Dietrich Baade and Ferdinando Patat from ESO.

"Our results strongly suggest a two-stage explosion process in this type of supernova," comments Wang. "This is an important finding with potential implications in cosmology".

Using observations of 17 supernovae made over more than 10 years with ESO's Very Large Telescope and the McDonald Observatory's Otto Struve Telescope, astronomers inferred the shape and structure of the debris cloud thrown out from Type Ia supernovae. Such supernovae are thought to be the result of the explosion of a small and dense star - a white dwarf - inside a binary system. As its companion continuously spills matter onto the white dwarf, the white dwarf reaches a critical mass, leading to a fatal instability and the supernova. But what sparks the initial explosion, and how the blast travels through the star have long been thorny issues.........

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November 28, 2006, 8:12 PM CT

Big Magnet Ready To Face The Big Questions

Big Magnet Ready To Face The Big Questions
The largest superconducting magnet ever built has successfully been powered up to its operating conditions at the first attempt. Called the Barrel Toroid because of its shape, this magnet is a vital part of ATLAS, one of the major particle detectors being prepared to take data at CERN's Large Hadron Collider (LHC), the new particle accelerator scheduled to turn on in November 2007. ATLAS will help researchers probe the big questions of the Universe - what happened in the moments after the Big Bang? Why does the material in the Universe behave the way it does? Why is the Universe we can see made of matter rather than anti-matter?

UK researchers are a key part of the ATLAS collaboration and Dr Richard Nickerson, UK ATLAS project leader, who is from the University of Oxford welcomed this important milestone "The toroidal magnets are critical to enabling us to measure the muons (a type of particle) produced in interactions. These are vital to a lot of the physics we want to study, so the successful test of the magnets is a great step forward".

The ATLAS Barrel Toroid consists of eight superconducting coils, each in the shape of a round-cornered rectangle, 5m wide, 25m long and weighing 100 tonnes, all aligned to millimetre precision. It will work together with other magnets in ATLAS to bend the paths of charged particles produced in collisions at the LHC, enabling important properties to be measured. Unlike most particle detectors, the ATLAS detector does not need large quantities of metal to contain the field because the field is contained within a doughnut shape defined by the coils. This allows the ATLAS detector to be very large, which in turn increases the precision of the measurements it can make.........

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November 22, 2006, 4:32 AM CT

First Live HDTV Broadcast From Space

First Live HDTV Broadcast From Space
Images from the world's first high definition television (HDTV) broadcast from space flashed across the screen on Nov 15th in Times Square. On Nov. 15, 2006, NASA made history with the first live HDTV broadcasts from space, in cooperation with the Japan Aerospace Exploration Agency, Discovery HD Theater and Japanese broadcast network NHK.

The two HDTV broadcasts featured Expedition 14 Commander Michael Lopez-Alegria on the International Space Station, with Flight Engineer Thomas Reiter serving as camera operator aboard the 220-mile-high laboratory.

"HDTV provides up to six times the resolution of regular analog video," said Rodney Grubbs, NASA principal investigator. "On previous missions, we've flown HDTV cameras but had to wait until after the mission to retrieve the tapes, watch the video and share it with the science and engineering community, the media and the public. For the first time ever, this test lets us stream live HDTV from space so the public can experience what its like to be there".

Known as the Space Video Gateway, the system transmits high bandwidth digital television signals to the ground that are not only spectacular, but also valuable to scientists, engineers and managers.

NASA and the Japan Aerospace Exploration Agency, along with both NHK and Discovery, are cooperating in this effort though a Space Act Agreement originally signed in 2002.........

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November 20, 2006, 8:33 PM CT

Fascinating Twin Star Explosions

Fascinating Twin Star Explosions twin-star-explosions
Credit: NASA/Swift/Stefan Immler
Scientists using NASA's Swift satellite stumbled upon a rare sight, two supernovas side by side in one galaxy. Large galaxies typically play host to three supernovas per century. Galaxy NGC 1316 has had two supernovas in less than five months, and a total of four supernova in 26 years, as far back as the records go. This makes NGC 1316 the most prodigious known producer of supernovas.

The first supernova, still visible on the "right" in the image, was detected on June 19, 2006, and was named SN 2006dd. The second supernova, on the immediate "left" in the image, was detected on November 5 and has been named SN 2006mr. (The central bright spot is the galaxy core, and the bright object to the far left, like an earring, is a foreground star.).

NGC 1316, a massive elliptical galaxy about 80 million light years way, has recently merged with a spiral galaxy. Mergers do indeed spawn supernovas by forcing the creation of new, massive stars, which quickly die and explode. Yet all four supernovas in NGC 1316 appear to be Type Ia, a variety previously not associated with galaxy mergers and massive star formation. Scientists are intrigued and are investigating whether the high supernova rate is a coincidence or a result of the merger. Swift was launched on this date, November 20, in 2004.........

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November 16, 2006, 4:35 AM CT

Relativistic Pinball Machine

Relativistic Pinball Machine Spitzer Infrared Image of Cassiopeia A
New clues about the origins of cosmic rays, mysterious high-energy particles that bombard the Earth, have been revealed using NASA's Chandra X-ray Observatory. An extraordinarily detailed image of the remains of an exploded star provides crucial insight into the generation of cosmic rays.

For the first time, astronomers have mapped the rate of acceleration of cosmic ray electrons in a supernova remnant. The new map shows that the electrons are being accelerated at close to the theoretically maximum rate. This discovery provides compelling evidence that supernova remnants are key sites for energizing charged particles.

The map was created from an image of Cassiopeia A, a 325-year-old remnant produced by the explosive death of a massive star. The blue, wispy arcs in the image trace the expanding outer shock wave where the acceleration takes place. The other colors in the image show debris from the explosion that has been heated to millions of degrees.

"Researchers have theorized since the 1960s that cosmic rays must be created in the tangle of magnetic fields at the shock, but here we can see this happening directly," said Michael Stage of the University of Massachusetts, Amherst. "Explaining where cosmic rays come from helps us to understand other mysterious phenomena in the high-energy universe".........

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