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Archive for January 15, 2013

Dark Energy Alternatives To Einstein Are Running Out Of Room

January 15, 2013 1 comment

Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team

Credit: NASA; ESA; G. Illingworth, D. Magee, and P. Oesch, University of California, Santa Cruz; R. Bouwens, Leiden University; and the HUDF09 Team

Research by University of Arizona astronomy professor Rodger Thompson finds that a popular alternative to Albert Einstein’s theory for the acceleration of the expansion of the universe does not fit newly obtained data on a fundamental constant, the proton to electron mass ratio.

Thompson’s findings, reported at the American Astronomical Society meeting in Long Beach, Calif., impact our understanding of the universe and point to a new direction for the further study of its accelerating expansion.

The acceleration can be explained by reinstating the “cosmological constant” into Einstein’s theory of General Relativity. Einstein originally introduced the term to make the universe stand still. When it was later found that the universe was expanding, Einstein called the cosmological constant “his biggest blunder.”

Full Story: http://uanews.org/story/dark-energy-alternatives-einstein-are-running-out-room

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Next-Generation Adaptive Optice Brings Remarkable Details To Light In Stellar Nursery

January 15, 2013 Leave a comment

Image Credit: Gemini Observatory/AURA

Image Credit: Gemini Observatory/AURA

A new image released today reveals how Gemini Observatory’s most advanced adaptive optics (AO) system will help astronomers study the universe with an unprecedented level of clarity and detail by removing distortions due to the Earth’s atmosphere. The photo, featuring an area on the outskirts of the famous Orion Nebula, illustrates the instrument’s significant advancements over previous-generation AO systems.

“The combination of a constellation of five laser guide stars with multiple deformable mirrors allows us to expand significantly on what has previously been possible using adaptive optics in astronomy,” said Benoit Neichel, who currently leads this adaptive optics program for Gemini. “For years our team has focused on developing this system, and to see this magnificent image, just hinting at its scientific potential, made our nights on the mountain – while most folks were celebrating the New Year’s holiday – the best celebration ever!”

The new system, called GeMS, is installed on the Gemini South telescope in Chile and is the first of its kind to use laser guide stars and a technology called Multi-Conjugate Adaptive Optics (MCAO) to image the sky.

Full Story and Photos: http://www.gemini.edu/node/11925

Herschel intercepts asteroid Apophis

January 15, 2013 Leave a comment

ESA’s Herschel space observatory made new observations of asteroid Apophis as it approached Earth this weekend. The data shows the asteroid to be bigger than first estimated, and less reflective.

Catalogued as asteroid (99942) Apophis (previously 2004 MN4), it is often nicknamed ‘the doomsday asteroid’ in popular media, after initial observations made after its discovery in 2004 gave it a 2.7% chance of striking Earth in April 2029. With additional data, however, an impact in 2029 was soon ruled out, although the asteroid will pass within 36 000 km of Earth’s surface, closer even than the orbits of geostationary satellites.

The asteroid will return to Earth’s neighbourhood again in 2036, but quite how close it will come then is uncertain, as the 2029 approach is predicted to alter its orbit substantially. Obtaining improved physical parameters for Apophis and its orbit is thus of great importance in being able to make better predictions of its future trajectory.

Full Story: http://www.esa.int/Our_Activities/Space_Science/Herschel_intercepts_asteroid_Apophis

NASA’s Hubble Reveals Rogue Planetary Orbit For Fomalhaut B

January 15, 2013 Leave a comment

Newly released NASA Hubble Space Telescope images of a vast debris disk encircling the nearby star Fomalhaut and a mysterious planet circling it may provide forensic evidence of a titanic planetary disruption in the system.

Astronomers are surprised to find the debris belt is wider than previously known, spanning a section of space from 14 to nearly 20 billion miles from the star. Even more surprisingly, the latest Hubble images have allowed a team of astronomers to calculate the planet follows an unusual elliptical orbit that carries it on a potentially destructive path through the vast dust ring.

The planet, called Fomalhaut b, swings as close to its star as 4.6 billion miles, and the outermost point of its orbit is 27 billion miles away from the star. The orbit was recalculated from the newest Hubble observation made last year.

“We are shocked. This is not what we expected,” said Paul Kalas of the University of California at Berkeley and the SETI Institute in Mountain View, Calif.

Full Story: http://www.nasa.gov/mission_pages/hubble/science/rogue-fomalhaut.html
Also: http://hubblesite.org/newscenter/archive/releases/2013/01

Galaxy’s Gamma-Ray Flares Erupted Far From Its Black Hole

January 15, 2013 Leave a comment

In 2011, a months-long blast of energy launched by an enormous black hole almost 11 billion years ago swept past Earth. Using a combination of data from NASA’s Fermi Gamma-ray Space Telescope and the National Science Foundation’s Very Long Baseline Array (VLBA), the world’s largest radio telescope, astronomers have zeroed in on the source of this ancient outburst.

Theorists expect gamma-ray outbursts occur only in close proximity to a galaxy’s central black hole, the powerhouse ultimately responsible for the activity. A few rare observations suggested this is not the case. The 2011 flares from a galaxy known as 4C +71.07 now give astronomers the clearest and most distant evidence that the theory still needs some work. The gamma-ray emission originated about 70 light-years away from the galaxy’s central black hole.

Full Story: http://www.nasa.gov/mission_pages/GLAST/news/aas-flares.html

NASA’s Kepler Mission Discovers 461 New Planet Candidates

January 15, 2013 Leave a comment

NASA’s Kepler mission Monday announced the discovery of 461 new planet candidates. Four of the potential new planets are less than twice the size of Earth and orbit in their sun’s “habitable zone,” the region in the planetary system where liquid water might exist on the surface of a planet.

One of the four newly identified super Earth-size planet candidates, KOI-172.02, orbits in the habitable zone of a star similar to our sun. The possible planet is approximately 1.5 times the radius of Earth and orbits its host star every 242 days. Additional follow-up analysis will be required to confirm the candidate as a planet.

“There is no better way to kickoff the start of the Kepler extended mission than to discover more possible outposts on the frontier of potentially life bearing worlds,” said Christopher Burke, Kepler scientist at the SETI Institute in Mountain View, Calif., who is leading the analysis.

Full Story: http://www.nasa.gov/mission_pages/kepler/news/kepler-461-new-candidates.html