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NASA’s Cassini Delivers Holiday Treats From Saturn

December 22, 2011 Leave a comment

Image credit: NASA/JPL-Caltech/SSI

Image credit: NASA/JPL-Caltech/SSI

No team of reindeer, but radio signals flying clear across the solar system from NASA’s Cassini spacecraft have delivered a holiday package of glorious images. The pictures, from Cassini’s imaging team, show Saturn’s largest, most colorful ornament, Titan, and other icy baubles in orbit around this splendid planet.

The release includes images of satellite conjunctions in which one moon passes in front of or behind another. Cassini scientists regularly make these observations to study the ever-changing orbits of the planet’s moons. But even in these routine images, the Saturnian system shines. A few of Saturn’s stark, airless, icy moons appear to dangle next to the orange orb of Titan, the only moon in the solar system with a substantial atmosphere. Titan’s atmosphere is of great interest because of its similarities to the atmosphere believed to exist long ago on the early Earth.

The images are online at: http://www.nasa.gov/cassini , http://saturn.jpl.nasa.gov and http://ciclops.org .

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2011-393

LHC Reports Discovery of Its First New Particle

December 22, 2011 Leave a comment

The Large Hadron Collider (LHC) on the Franco-Swiss border has made its first clear observation of a new particle since opening in 2009.

It is called Chi_b (3P) and will help scientists understand better the forces that hold matter together.

The as-yet unpublished discovery is reported on the Arxiv pre-print server.

The LHC is exploring some of the fundamental questions in “big physics” by colliding proton particles together in a huge underground facility.

Detail in the sub-atomic wreckage from these impacts is expected to yield new information about the way the Universe is constructed.

Full Story: http://www.bbc.co.uk/news/science-environment-16301908

Some Nearby Stars May Be Older than We Thought

December 22, 2011 Leave a comment

Low in the south in the summer sky shines the constellation Scorpius and the bright, red supergiant star Antares. Many of the brightest stars in Scorpius, and hundreds of its fainter stars, are among the youngest stars found near the earth, and a new analysis of them may result in a rethinking of both their ages and the ages of other groups of stars.

New research by astrophysicists from the University of Rochester focused on stars in the north part of the constellation, known as Upper Scorpius, which is a part of the Scorpius-Centaurus OB association, one of our best studied groups of young stars and a benchmark sample for investigating the early lives of stars and the evolution of their planet-spawning disks. The Upper Scorpius stellar group lies roughly 470 light years from Earth.

While those stars have been thought to be just five million years old, the team concludes that those stars are actually more than twice as old, at 11 million years of age. The findings are surprising given Upper Scorpius’s status as one of the best-studied samples of young stars in the sky.

Full Story: http://www.rochester.edu/news/show.php?id=3977

Mechanism Explains Why Universe Was Born with 3 Dimensions

December 22, 2011 Leave a comment

According to Big Bang cosmology, the universe originated in an explosion from an invisibly tiny point. This theory is strongly supported by observation of the cosmic microwave background*2 and the relative abundance of elements. However, a situation in which the whole universe is a tiny point exceeds the reach of Einstein’s general theory of relativity, and for that reason it has not been possible to clarify how the universe actually originated.

In superstring theory, which is considered to be the “theory of everything”, all the elementary particles are represented as various oscillation modes of very tiny strings.
Among those oscillation modes, there is one that corresponds to a particle that mediates gravity, and thus the general theory of relativity can be naturally extended to the scale of elementary particles. Therefore, it is expected that superstring theory allows the investigation of the birth of the universe. However, actual calculation has been intractable because the interaction between strings is strong, so all investigation thus far has been restricted to discussing various models or scenarios.

Superstring theory predicts a space with 9 dimensions*3, which poses the big puzzle of how this can be consistent with the 3-dimensional space that we live in.

Full Story: http://www.kek.jp/intra-e/press/2011/122209/

First Low-Mass Star Detected in Globular Cluster

December 22, 2011 Leave a comment

Until now, it was merely assumed that low-mass and therefore extremely faint stars must exist. However, in view of the vast distances and weak luminosity of low-mass stars, even the most modern telescopes fail. Together with a Polish-Chilean team of researchers, Swiss astrophysicist Philippe Jetzer from the University of Zurich has now detected the first low-mass star in the globular cluster M22 indirectly. As their recent article accepted for publication in Astrophysical Journal Letters reveals, it involves a dwarf star that has less than a fifth of the mass of our sun and is 3.2 kiloparsecs from it (one kiloparsec corresponding to 3,210 light years).

The evidence, which enables the mass to be determined highly accurately, is based upon so-called gravitational microlensing and requires the highest technical standards available. The measurements were carried out on the ESO VLT 8-meter telescope with adaptive optics at the Paranal Observatory in Chile.

Full Story: http://www.mnf.uzh.ch/en/news/detailview/archive/2011/12/article/erstmals-massearmer-stern-in-kugelsternhaufen-nach.html

Cryogenic Testing Completed for JWST Mirrors

December 22, 2011 Leave a comment

Cryogenic testing is complete for the final six primary mirror segments and a secondary mirror that will fly on NASA’s James Webb Space Telescope. The milestone represents the successful culmination of a process that took years and broke new ground in manufacturing and testing large mirrors.

“The mirror completion means we can build a large, deployable telescope for space,” said Scott Willoughby, vice president and Webb program manager at Northrop Grumman Aerospace Systems. “We have proven real hardware will perform to the requirements of the mission.”

The Webb telescope has 21 mirrors, with 18 mirror segments working together as a large 21.3-foot (6.5-meter) primary mirror. Each individual mirror segment now has been successfully tested to operate at 40 Kelvin (-387 Fahrenheit or -233 Celsius).

Full Story: http://www.nasa.gov/topics/technology/features/webb-mirror-cryo.html

Planet Discovery Raises Questions About Star Evolution

December 22, 2011 Leave a comment

University of Toulouse and University of Montreal researchers have detected two planets of sizes comparable to Earth orbiting around an old star that has just passed the red giant stage. This planetary system is located near Lyra and Cygnus constellations at a distance of 3900 light years. This discovery, to be published by in Nature on December 22 2011, may shed new light on the destiny of stellar and planetary systems.

“The two planets, named KOI 55.01 and KOI 55.02, are on very short orbits around their host star,” explained University of Montreal astrophysicist Gilles Fontaine and member of the Center for research in astrophysics of Québec (CRAQ). “Having migrated so close, they probably plunged deep into the star’s envelope during the red giant phase, but survived. The two observed bodies would then be the dense cores of ancient giant planets whose gaseous envelopes were vaporized during the immersion phase.” The host star, KIC 05807616, consists of the exposed core of a red giant that has lost nearly its entire envelope, and in fact the planets may have contributed to the increased loss of mass that is necessary for the formation of this type of star. This has lead the researchers to theorize that planetary systems in general may therefore influence the evolution of their parent stars.

Full Story: http://www.nouvelles.umontreal.ca/udem-news/news/20111221-discovery-of-two-earth-size-planets-raises-questions-about-the-evolution-of-stars.html