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2 Types of Neutron Stars Point to 2 Types of Supernovae

November 10, 2011 Leave a comment

Southampton astronomers have found evidence that neutron stars, which are produced when massive stars explode as supernovae, actually come in two distinct varieties. Their finding also suggests that each variety is produced by a different kind of supernova event.

Neutron stars are the last stage in the evolution of many massive stars. They represent the most extreme form of matter: the mass of a single neutron star exceeds that of the entire sun, but squeezed into a ball whose diameter is smaller than that of London.

In a paper which will be published this week in Nature, Professors Christian Knigge and Malcolm Coe from the University of Southampton worked with Philipp Podsiadlowski of Oxford University to reveal how they have discovered two distinct populations of neutron stars that appear to have formed via two different supernova channels.

Full Story: http://www.soton.ac.uk/mediacentre/features/nuetron_star_supernova.shtml

Rare & Beautiful Meteorite Found By Missouri Farmer

November 10, 2011 Leave a comment

Last January two amateur meteorite hunters dropped by Randy Korotev’s office at Washington University in St. Louis to show him their latest purchase, a 17-kilogram pallasite meteorite found in 2006 near Conception Junction (population 202) in northwest Missouri.

Korotev, research professor in earth and planetary sciences in Arts & Sciences and an expert in lunar meteorites, identified the stone as of a fragment of an asteroid. His lab also analyzed crystals within the rock to help identify its body of origin, eventually referring the meteorite hunters to the University of California, Los Angeles (UCLA), for analysis of the metal in which the crystals are embedded.

The meteorite is a pallasite, a type of meteorite named for Peter Pallas, a German naturalist who first described one in 1749.

These meteorites consist of green olivine crystals embedded in an iron-nickel matrix like cherries in a pie, a rock type so odd that it was the first to be identified as extraterrestrial.

Full Story: http://news.wustl.edu/news/Pages/22942.aspx

NASA’s New Upper Stage Engine Passes Major Test

November 10, 2011 Leave a comment

NASA conducted a successful 500-second test firing of the J-2X rocket engine on Wednesday, Nov. 9, marking another important step in development of an upper stage for the heavy-lift Space Launch System (SLS).

SLS will carry the Orion spacecraft, its crew, cargo, equipment and science experiments to destinations in deep space. SLS will be safe, affordable and sustainable to continue America’s journey of discovery from the unique vantage point of space.

“The J-2X engine is critical to the development of the Space Launch System,” Dan Dumbacher, NASA’s deputy associate administrator for exploration systems development, said after the test at NASA’s Stennis Space Center in Mississippi. “Today’s test means NASA is moving closer to developing the rocket it needs if humans are to explore beyond low-Earth orbit.”

Full Story: http://www.nasa.gov/home/hqnews/2011/nov/HQ_11-380_J-2X_Test.html

Potential New NASA Mission Would Reveal the Hearts of Undead Stars

November 10, 2011 Leave a comment

Credit: NASA

Credit: NASA

Neutron stars have been called the zombies of the cosmos, shining on even though they’re technically dead, and occasionally feeding on a neighboring star if it gets too close.

They are born when a massive star runs out of fuel and collapses under its own gravity, crushing the matter in its core and blasting away its outer layers in a supernova explosion that can outshine a billion suns.

The core, compressed by gravity to inconceivable density – one teaspoon would weigh about a billion tons on Earth – lives on as a neutron star. Although the nuclear fusion fires that sustained its parent star are extinguished, it still shines with heat left over from its explosive formation, and from radiation generated by its magnetic field, which became intensely concentrated as the core collapsed, and can be over a trillion times stronger than Earth’s.

Although its parent star could easily have been more than a million miles across, a neutron star is only about the size of a city. However, its intense gravity makes it the ultimate trash compactor, capable of packing in an astonishing amount of matter, more than 1.4 times the content of the Sun, or at least 460,000 Earths.

Full Story: http://www.nasa.gov/topics/universe/features/nicer-science.html

Was the Real Discovery of the Expanding Universe Lost in Translation?

November 10, 2011 Leave a comment

Credit: NASA, ESA, and A. Feild (STScI)

Credit: NASA, ESA, and A. Feild (STScI)

The greatest astronomical discovery of the 20th century may have been credited to the wrong person. But it turns out to have been nobody’s fault except for that of the actual original discoverer himself.

Writing in the November 10th issue of the journal Nature, astrophysicist Mario Livio of the Space Telescope Science Institute has put to bed a growing conspiracy theory about who was fairly credited for discovering the expanding universe.

For nearly a century, American astronomer Edwin P. Hubble has held the fame for this landmark discovery, which would recast all of 20th century astronomy. Hubble reported that the universe is uniformly expanding in all directions. It solved Einstein’s dilemma of explaining why the universe didn’t already collapse under its own gravity.

Ironically, Hubble never got a Nobel Prize for this discovery, though astronomers from two teams who independently uncovered evidence for an accelerating universe won the 2011 Noble Prize in Physics. But Hubble did get the most celebrated telescope of modern history named after him.

Full Story: http://hubblesite.org/newscenter/archive/releases/2011/36/full/

Hubble Uncovers Tiny Galaxies Bursting with Starbirth in Early Universe

November 10, 2011 Leave a comment

Using its infrared vision to peer nine billion years back in time, the NASA/ESA Hubble Space Telescope has uncovered an extraordinary population of tiny, young galaxies that are brimming with star formation.

The galaxies are churning out stars at such a rate that the number of stars in them would double in just ten million years. For comparison, the Milky Way has taken a thousand times longer to double its stellar population.

These newly discovered dwarf galaxies are around a hundred times smaller than the Milky Way. Their star formation rates are extremely high, even for the young Universe, when most galaxies were forming stars at higher rates than they are today. They have turned up in the Hubble images because the radiation from young, hot stars has caused the oxygen in the gas surrounding them to light up like a fluorescent sign.

Astronomers believe this rapid starbirth represents an important phase in the formation of dwarf galaxies, the most common galaxy type in the cosmos.

Full Story: http://www.spacetelescope.org/news/heic1117/