27
May 11

NASA'S Spitzer Sees Crystal "Rain" In Outer Clouds Of Infant Star

Source: NASA-Spitzer


Image credit: NASA/JPL-Caltech/University of Toledo

 

Tiny crystals of a green mineral called olivine are falling down like rain on a burgeoning star, according to observations from NASA's Spitzer Space Telescope.

This is the first time such crystals have been observed in the dusty clouds of gas that collapse around forming stars. Astronomers are still debating how the crystals got there, but the most likely culprits are jets of gas blasting away from the embryonic star.(read more)

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27
May 11

Scientists make lunar watershed discovery

Source: NASA Lunar Science Institute

A team of NASA-funded researchers has measured for the first time water from the moon in the form of tiny globules of molten rock, which have turned to glass-like material trapped within crystals. Data from these newly-discovered lunar melt inclusions indicate the water content of lunar magma is 100 times higher than previous studies suggested.

The inclusions were found in lunar sample 74220, the famous high-titanium "orange glass soil" of volcanic origin collected during the Apollo 17 mission in 1972. The scientific team used a state-of-the-art ion microprobe instrument to measure the water content of the inclusions, which were formed during explosive eruptions on the moon approximately 3.7 billion years ago.

The results published in the May 26 issue of Science Express raise questions about aspects of the "giant impact theory" of how the moon was created. That theory predicted very low water content of lunar rock due to catastrophic degassing during the collision of Earth with a Mars-sized body very early in its history. (read more)

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27
May 11

Most distant object ever discovered by SWIFT

Source: NASA SWIFT


Image credit: Gemini Observatory/AURA/NASA/ Levan, Tanvir, Cucchiara, Fox

NASA's Swift satellite has found the most distant gamma-ray burst ever detected. The blast, designated GRB 080913, arose from an exploding star 12.8 billion light-years away. (read more)

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27
May 11

Has Fermi glimpsed dark matter?

Source: Physics World

New results from NASA's Fermi Gamma-Ray Space Telescope appear to confirm a larger-than-expected rate of high-energy positrons reaching the Earth from outer space. This anomaly in the cosmic-ray flux was first observed by the Italian-led PAMELA spacecraft in 2008 and suggests the existence of annihilating dark-matter particles. (read more)

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27
May 11

Hubble finds rare 'Blue Straggler' starsin Milky Way's hub

Source: NASA News


Blue straggler stars in the Milky Way bulge.
Credit: NASA, ESA, W. Clarkson (Indiana University and UCLA), and K. Sahu (STScl)

NASA's Hubble Space Telescope has found a rare class of oddball stars called blue stragglers in the hub of our Milky Way, the first detected within our galaxy's bulge.

Blue stragglers are so named because they seemingly lag behind in the aging process, appearing younger than the population from which  they formed. While they have been detected in many distant star clusters, and among nearby stars, they never have been seen inside the core  of our galaxy.

It is not clear how blue stragglers form. A common theory is that they emerge from binary pairs. As the more massive star evolves and expands, the smaller star gains material from its companion. This stirs up hydrogen fuel and causes the growing star to undergo nuclear fusion at a faster rate. It burns hotter and bluer, like a massive young star.

The findings support the idea that the Milky Way's central bulge stopped making stars billions of years ago. It now is home to aging sun-like stars and cooler red dwarfs. Giant blue stars that once lived there have long since exploded as supernovae. The results have been accepted for publication in an upcoming issue of The Astrophysical Journal. Lead author Will Clarkson of Indiana University in Bloomington, will discuss them today at the American Astronomical Society meeting in Boston. (read more)

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