081219
December 20, 2008 on 4:37 am | In Uncategorized | Comments Offhttp://science.nasa.gov/headlines/y2008/15dec_solarflaresurprise.htm?list1088553
In 2006, one of the largest solar flares observed for 30 years erupted, saturating X-ray cameras on board observatories orbiting Earth.
Pure hydrogen streamed past the spacecraft for a full 90 minutes, but they cannot exist in the extreme environment surrounding the flare site. “We believe they began their journey to Earth in pieces, as protons and electrons,” said Richard Mewaldt of Caltech. “Before they escaped the sun’s atmosphere, however, some of the protons recaptured an electron, forming intact hydrogen atoms. The atoms left the sun in a fast, straight shot before they could be broken apart again.”
http://arxiv.org/abs/0812.2720
Chandra observations of large samples of galaxy clusters detected in X-rays by ROSAT provide a new, robust determination of the cluster mass functions at low and high redshifts. => dark energy is the cosmological constant.
http://www.nrao.edu/pr/2008/farwater/
Effelsberg telescope and VLA found the most distant water yet seen in the Universe, in a galaxy more than 11 billion light-years from Earth. The galaxy, dubbed MG J0414+0534 has a quasar at its core. In the region near the core, the water molecules are acting as masers to amplify radio waves at a specific frequency. Additionally, another galaxy was used as a gravitational lens to magnify the radio signals used to detect the water molecules.
081210
December 10, 2008 on 4:47 pm | In Uncategorized | Comments Offhttp://www.eso.org/public/outreach/press-rel/pr-2008/pr-46-08.html
16 year observation campaign of a region right in the centre of our galaxy where 28 stars have been tracked.
the study’s first author, Stefan Gillessen.: “Ordered motion outside the central light-month, randomly oriented orbits inside – that’s how the dynamics of the young stars in the Galactic Centre are best described.”
ESO VLT
http://www.nasa.gov/mission_pages/spitzer/multimedia/20081208.html
NASA’s Spitzer Space Telescope has captured a new, infrared view of the choppy star-making cloud called M17, or the Swan nebula.
The cloud, located about 6,000 light-years away in the constellation Sagittarius, is dominated by a central group of massive stars — the most massive stars in t he region. These central stars give off intense flows of expanding gas, whichrush like rivers against dense piles of material, carving out the deep pocket at center of the picture. Winds from the region’s other massive stars push back against these oncoming rivers, creating bow shocks like those that pile up in front of speeding boats.
http://www.universetoday.com/2008/12/08/hubbles-early-festivities-imaging-the-m13-globular-cluster-snow-globe/
the stars contained within clusters like M13 are thought to be amongst the oldest known in the Universe. These clusters in the Milky Way halo are thought to have formed well before any stars existed in today’s Milky Way spiral disk.
Blue stragglers are formed when the gas from one star is siphoned off by another. This rejuvenates one of the stars,
081205
December 6, 2008 on 3:32 am | In Uncategorized | Comments Offhttp://www.universetoday.com/2008/12/03/swift-detects-x-ray-emissions-from-comets/
there is an interesting quirk as most comets interact with the solar wind within 3AU from the solar surface.
Energetic solar wind ions impact the coma, capturing electrons from neutral atoms. As the electrons become attached to their new parent nuclei (the solar wind ion), energy is released in the form of X-rays.
http://www.plasma-universe.com/index.php/Comet
http://www.universetoday.com/2008/12/03/astronomers-time-travel-to-16th-century-supernova/
A ‘light echo’ is light from the original supernova event that bounces off dust particles in surrounding interstellar clouds and reaches Earth many years after the direct light passes by.
Supernova 1572 was very typical of a Type Ia supernova.
http://www.universetoday.com/2008/12/03/brown-dwarfs-form-like-stars/
brown dwarfs are more like stars than planets.
the theoretical minimum mass for a star to sustain nuclear fusion is 75 times Jupiter.
081202
December 1, 2008 on 5:16 am | In Uncategorized | Comments Offhttp://www.universetoday.com/2008/11/24/supersonic-bubbles-blown-by-black-holes-regulate-size/
creating the bubbles may stunt the growth of the black hole, as well as curb star formation in elliptical galaxies.
M84 has just such a black hole, and at the ends of each of its jets large cavities of ionized gas (plasma) form. The bubbles measure 13,000 light years across, and are formed about every 10 million years.
http://www.universetoday.com/2008/11/25/unusual-red-spiral-galaxies-strangled/
Spiral galaxies appear blue because they are still dynamically forming hot young stars. Elliptical galaxies, on the other hand, are mostly old, dead, and red.
As a blue galaxy is drawn in by gravity from the rural regions to the suburbs, some sort of an interaction with its environment causes a slow-down in star formation.
Usually, anything disruptive enough to get rid of the gas that fuels the star formation would have disrupted the spiral arms.
Whenever you show a red object to an astronomer they immediately blame dust.
Whenever you see star formation being turned off, we like to blame the black hole.
http://www.universetoday.com/2008/11/25/hannys-voorwerp-revealed/
new observations made by radio telescopes may have finally revealed the nature of the “Hanny’s Voorwerp” (Dutch for “object.”) It appears as though a jet of highly energetic particles is being generated by a massive black hole at the center of IC2497, creating an ionized gas cloud.
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