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X-Raying Stellar Winds in a High-Speed Collision

October 12, 2012 Leave a comment

Two massive stars racing in orbit around each other have had their colliding stellar winds X-rayed for the first time, thanks to the combined efforts of ESA’s XMM-Newton and NASA’s Swift space telescopes.

Stellar winds, pushed away from a massive star’s surface by its intense light, can have a profound influence on their environment.

Now, XMM-Newton and Swift have found a ‘Rosetta stone’ for such winds in a binary system known as Cyg OB2 #9, located in the Cygnus star-forming region, where the winds from two massive stars orbiting around each other collide at high speeds.

“This is the first time that we have found clear evidence for colliding winds in this system,” says Yael Nazé of the Université de Liège, Belgium, and lead author of the paper describing the results reported in Astronomy & Astrophysics.

Full Story: http://www.esa.int/esaSC/SEM3H93S18H_index_0.html
Also: http://sci.esa.int/science-e/www/object/index.cfm?fobjectid=50904

When Galaxies Eat Galaxies: Gravity Lenses Suggest Big Collisions Make Galaxies Dense

October 12, 2012 Leave a comment

Using gravitational “lenses” in space, University of Utah astronomers discovered that the centers of the biggest galaxies are growing denser – evidence of repeated collisions and mergers by massive galaxies with 100 billion stars.

“We found that during the last 6 billion years, the matter that makes up massive elliptical galaxies is getting more concentrated toward the centers of those galaxies. This is evidence that big galaxies are crashing into other big galaxies to make even bigger galaxies,” says astronomer Adam Bolton, principal author of the new study.

“Most recent studies have indicated that these massive galaxies primarily grow by eating lots of smaller galaxies,” he adds. “We’re suggesting that major collisions between massive galaxies are just as important as those many small snacks.”

Full Story: http://unews.utah.edu/news_releases/when-galaxies-eat-galaxies/

Mars Rock Touched By NASA Curiosity Has Surprises

October 12, 2012 1 comment

Image credit: NASA/JPL-Caltech/MSSS

The first Martian rock NASA’s Curiosity rover has reached out to touch presents a more varied composition than expected from previous missions. The rock also resembles some unusual rocks from Earth’s interior.

The rover team used two instruments on Curiosity to study the chemical makeup of the football-size rock called “Jake Matijevic” (matt-EE-oh-vick) The results support some surprising recent measurements and provide an example of why identifying rocks’ composition is such a major emphasis of the mission. Rock compositions tell stories about unseen environments and planetary processes.

“This rock is a close match in chemical composition to an unusual but well-known type of igneous rock found in many volcanic provinces on Earth,” said Edward Stolper of the California Institute of Technology in Pasadena, who is a Curiosity co-investigator. “With only one Martian rock of this type, it is difficult to know whether the same processes were involved, but it is a reasonable place to start thinking about its origin.”

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2012-318#1

Las Cumbres Observatory Achieves First Light With NRES Spectrograph

October 12, 2012 Leave a comment

Las Cumbres Observatory Global Telescope (LCOGT), a private, nonprofit scientific institution conducting time domain astrophysics and education, and a provider of global telescope resources, achieved first light with their prototype Network of Robotic Echelle Spectrograph (NRES) this week. The event took place earlier in the week at LCOGT’s Byrne Observatory located at the UC Santa Barbara Sedgwick Reserve.

Primarily designed to support the study of exoplanets, the NRES prototype represents over two years of concentrated science and engineering work by Las Cumbres Observatory. Tim Brown, LCOGT Science Director, has overseen the design and funding of the project, while mechanical engineer John Hygelund and astronomy postdoc Jason Eastman have built and tested, and then installed the device.

According to Eastman, “We adopted an optical design that is both simple and conventional in its general approach, similar in concept to spectrographs designed for the Palomar East Arm Echelle, the Lick Automated Planet Finder, and others.” The in-house design enabled Las Cumbres to optimize the spectrograph for a small production run and robotic use. This, because the biggest difference with the NRES will be that there will be six of them, deployed at six geographically distributed sites around the world, and integrated through a global telescope scheduling and control system.

Full Story: http://lcogt.net/press-release/las-cumbres-observatory-achieves-first-light-nres-spectrograph

Bouncing On Titan

October 12, 2012 Leave a comment

ESA’s Huygens probe bounced, slid and wobbled its way to rest in the 10 seconds after touching down on Saturn’s moon, Titan, in January 2005, a new analysis reveals. The findings provide novel insight into the nature of the moon’s surface.

Scientists reconstructed the chain of events by analysing data from a variety of instruments that were active during the impact, in particular changes in the acceleration experienced by the probe.

“A spike in the acceleration data suggests that during the first wobble, the probe likely encountered a pebble protruding by around 2 cm from the surface of Titan, and may have even pushed it into the ground, suggesting that the surface had a consistency of soft, damp sand,” describes Dr Stefan Schröder of the Max Planck Institute for Solar System Research, lead author of the paper reporting the results in Planetary and Space Science.

Full Story: http://www.esa.int/esaSC/SEMJP13S18H_index_0.html
Also: http://uanews.org/story/bounce-skid-wobble-how-huygens-landed-titan
Also: http://www.jpl.nasa.gov/news/news.php?release=2012-317

Scientists Find First Evidence Of Dynamo Generation On An Asteroid

October 12, 2012 Leave a comment

Vesta asteroid taken by NASA’s Dawn spacecraft. Image: NASA/JPL-Caltech/UCAL/MPS/DLR/IDA

A new study published this week in Science has found evidence that Vesta, the second-most-massive asteroid in the solar system, once harbored a dynamo — a molten, swirling mass of conducting fluid generating a magnetic field — resembling that in much larger planets like Earth. Researchers at MIT say the findings suggest that asteroids like Vesta may have been more than icy chunks of space debris.

“We’re filling in the story of basically what happened during those first few million years of the solar system, when an entire solar system was dominated by objects like this,” says Roger Fu, a graduate student in MIT’s Department of Earth, Atmospheric and Planetary Sciences (EAPS), and the study’s first author. “These bodies are really like miniature planets.”

“Vesta becomes now the smallest known planetary object to have generated a dynamo,” says co-author Benjamin Weiss, an associate professor of planetary sciences in EAPS. “You can imagine many asteroids in the early solar system were doing this.”

Full Story: http://web.mit.edu/newsoffice/2012/scientists-discover-dynamo-on-asteroid-1011.html

Nearby super-Earth Likely A Diamond Planet

October 12, 2012 Leave a comment

New research led by Yale University scientists suggests that a rocky planet twice Earth’s size orbiting a nearby star is a diamond planet.

“This is our first glimpse of a rocky world with a fundamentally different chemistry from Earth,” said lead researcher Nikku Madhusudhan, a Yale postdoctoral researcher in physics and astronomy. “The surface of this planet is likely covered in graphite and diamond rather than water and granite.”

The planet orbits at hyper speed — its year lasts just 18 hours, in contrast to Earth’s 365 days. It is also blazingly hot, with a temperature of about 3,900 degrees Fahrenheit, researchers said, a far cry from a habitable world.

Full Story: http://news.yale.edu/2012/10/11/nearby-super-earth-likely-diamond-planet