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Spacetime: A Smoother Brew Than We Knew

August 23, 2012 Leave a comment

Spacetime may be less like beer and more like sipping whiskey. Or so an intergalactic photo finish would suggest.

Physicist Robert Nemiroff of Michigan Technological University reached this heady conclusion after studying the tracings of three photons of differing wavelengths that had been recorded by NASA’s Fermi Gamma-ray Space Telescope in May 2009.

The photons originated about 7 billion light years away from Earth in one of three pulses from a gamma-ray burst and arrived at the orbiting telescope just one millisecond apart, in a virtual tie

“Gamma-ray bursts can tell us some very interesting things about the universe,” Nemiroff said. In this case, those three photons recorded by the Fermi telescope suggest that spacetime may not be not as bubbly as some scientists think.

Full Story: http://www.mtu.edu/news/stories/2012/august/story76807.html

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ChemCam Laser First Analyses Yield Beautiful Results

August 23, 2012 Leave a comment

Members of the Mars Science Laboratory Curiosity rover ChemCam team, including Los Alamos National Laboratory scientists, squeezed in a little extra target practice after zapping the first fist-sized rock that was placed in the laser’s crosshairs last weekend.

Much to the delight of the scientific team, the laser instrument has fired nearly 500 shots so far that have produced strong, clear data about the composition of the Martian surface.

“The spectrum we have received back from Curiosity is as good as anything we looked at on Earth,” said Los Alamos National Laboratory planetary scientist Roger Wiens, Principal Investigator of the ChemCam Team. “The entire MSL team was very excited about this and we popped a little champagne.”

Full Story: http://www.lanl.gov/news/releases/chemcam-laser-first-analyses-yield-beautiful-results.html

NASA’s WISE Scientists To Discuss Black Holes And Extreme Objects

August 23, 2012 Leave a comment

Artist’s concept of WISE. Image credit: NASA/JPL-Caltech

NASA will host a news teleconference at 10 a.m. PDT (1 p.m. EDT), Wednesday, Aug. 29, to announce new discoveries from its Wide-field Infrared Survey Explorer (WISE). The discoveries are related to the distant universe, including supermassive black holes and rare galaxies.

Full Story and Links: http://www.jpl.nasa.gov/news/news.cfm?release=2012-257b

Supernovae Of The Same Brightness, Cut From Vastly Different Cosmic Cloth

August 23, 2012 Leave a comment

The supernova PTF 11kx can be seen as the blue dot on the galaxy. Image Credit: BJ Fulton, Las Cumbres Observatory Global Telescope Network

Exploding stars called Type 1a supernova are ideal for measuring cosmic distance because they are bright enough to spot across the Universe and have relatively the same luminosity everywhere. Although astronomers have many theories about the kinds of star systems involved in these explosions (or progenitor systems), no one has ever directly observed one—until now.

In the August 24 issue of Science, the multi-institutional Palomar Transient Factory (PTF) team presents the first-ever direct observations of a Type 1a supernova progenitor system. Astronomers have collected evidence indicating that the progenitor system of a Type 1a supernova, called PTF 11kx, contains a red giant star. They also show that the system previously underwent at least one much smaller nova eruption before it ended its life in a destructive supernova. The system is located 600 million light years away in the constellation Lynx.

By comparison, indirect observations of another Type 1a supernova progenitor system (called SN 2011fe, conducted by the PTF team last year) showed no evidence of a red giant star. Taken together, these observations unequivocally show that just because Type 1a supernovae look the same, that doesn’t mean they are all born the same way.

Full Story: http://newscenter.lbl.gov/news-releases/2012/08/23/supernovae-of-the-same-brightness/

New Findings Show Some Type Ia Supernovae Linked To Novae

August 23, 2012 Leave a comment

In the August 24 issue of the journal Science, astronomers show for the first time that at least some thermonuclear (Type Ia) supernovae come from a recurrent nova. The results of the study, led by Ben Dilday, a postdoctoral researcher in physics at UC Santa Barbara and at Las Cumbres Observatory Global Telescope Network (LCOGT), are surprising because previous indirect –– but strong –– evidence had pointed to the merger of two white dwarf stars as the originators of other Type Ia supernovae.

The authors conclude that there are multiple ways to make a Type Ia supernova –– a finding that could have implications for understanding the differences seen in these “standard candles,” that were used to reveal the presence of dark energy.

Full Story:  http://www.ia.ucsb.edu/pa/display.aspx?pkey=2810

Link Found Between Cold European Winters And Solar Activity

August 23, 2012 2 comments

CREDIT: Warburg, via Wikimedia Commons

Scientists have long suspected that the Sun’s 11-year cycle influences climate of certain regions on Earth. Yet records of average, seasonal temperatures do not date back far enough to confirm any patterns. Now, armed with a unique proxy, an international team of researchers show that unusually cold winters in Central Europe are related to low solar activity — when sunspot numbers are minimal. The freezing of Germany’s largest river, the Rhine, is the key.

From the early 19th through mid-20th centuries, riverboat men used the Rhine for cargo transport. And so docks along the river have annual records of when ice clogged the waterway and stymied shipping. The scientists used these easily-accessible documents, as well as other additional historical accounts, to determine the number of freezing episodes since 1780.

Mapping the freezing episodes against the solar activity’s 11-year cycle — a cycle of the Sun’s varying magnetic strength and thus total radiation output — Sirocko and his colleagues determined that ten of the fourteen freezes occurred during years when the Sun had minimal sunspots. Using statistical methods, the scientists calculated that there is a 99 percent chance that extremely cold Central European winters and low solar activity are inherently linked.

Full Story: http://www.agu.org/news/press/pr_archives/2012/2012-39.shtml

The Milky Way Now Has A Twin (Or Two)

August 23, 2012 Leave a comment

Image Credit: Dr Aaron Robotham, ICRAR/St Andrews using GAMA data

The Milky Way is a fairly typical galaxy on its own, but when paired with its close neighbours – the Magellanic Clouds – it is very rare, and could have been one of a kind, until a survey of our local Universe found another two examples just like us.

Astronomer Dr Aaron Robotham, jointly from the University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR) and the University of St Andrews in Scotland, searched for groups of galaxies similar to ours. “We’ve never found another galaxy system like the Milky Way before, which is not surprising considering how hard they are to spot! It’s only recently become possible to do the type of analysis that lets us find similar groups,” says Dr Robotham.

“We found about 3% of galaxies similar to the Milky Way have companion galaxies like the Magellanic Clouds, which is very rare indeed. In total we found 14 galaxy systems that are similar to ours, with two of those being an almost exact match,” says Dr Robotham.

Full Story: http://www.icrar.org/news/news_items/media-releases/the-milky-way-now-has-a-twin-or-two