Archive

Archive for November 21, 2012

Failed Explosions Explain Most Peculiar Supernovae

November 21, 2012 Leave a comment

Supercomputer simulations have revealed that a type of oddly dim, exploding star is probably a class of duds—one that could nonetheless throw new light on the mysterious nature of dark energy.

Most of the thousands of exploding stars classified as type Ia supernovae look similar, which is why astrophysicists use them as accurate cosmic distance indicators. They have shown that the expansion of the universe is accelerating under the influence of an unknown force now called dark energy. Yet approximately 20 type Ia supernovae look peculiar.

“They’re all a little bit odd,” said George Jordan, a research scientist at the University of Chicago’s Flash Center for Computational Science. Comparing odd type Ia supernovae to normal ones may permit astrophysicists to more precisely define the nature of dark energy, he noted.

Jordan and three colleagues, including his chief collaborator on the project, Hagai Perets, assistant professor of physics at Technion – Israel Institute of Technology, have found that the peculiar type Ia supernovae are probably white dwarf stars that failed to detonate. “They ignite an ordinary flame and they burn, but that isn’t followed by a triggering of a detonation wave that goes through the star,” Jordan said.

Full Story: http://news.uchicago.edu/article/2012/11/19/failed-explosions-explain-most-peculiar-supernovae

$20 Million CU Instrument Package Set For Integration On Mars Spacecraft

November 21, 2012 Leave a comment

A $20 million remote sensing instrument package built by the University of Colorado Boulder, which is leading a 2013 NASA mission to understand how Mars might have lost its atmosphere, has been delivered to Lockheed Martin in Littleton, Colo., for spacecraft integration.

“With the delivery of this package, we are shifting from assembling the basic spacecraft to focusing on getting the science instruments onto the spacecraft,” said Jakosky, also a professor in the geological sciences department. “This is a major step toward getting us to launch and then getting the science return from the mission.”

Full Story: http://www.colorado.edu/news/releases/2012/11/16/20-million-cu-instrument-package-set-integration-mars-spacecraft

Hubble Traps Galactic Fireflies

November 21, 2012 Leave a comment

Credit: ESA/NASA/Hubble

Luminous galaxies glow like fireflies on a dark night in this image snapped by the NASA/ESA Hubble Space Telescope. The upper central galaxy in this image is a gigantic elliptical galaxy designated 4C 73.08. A prominent spiral galaxy seen from “above” shines in the lower part of the image, while examples of galaxies viewed edge-on also populate the cosmic landscape.

In the optical and near-infrared light captured to make this image, 4C 73.08 does not appear all that beastly. But when viewed in longer wavelengths the galaxy takes on a very different appearance. Dust-piercing radio waves reveal plumes emanating from the core, where a supermassive black hole spews out twin jets of material. 4C 73.08 is classified as a radio galaxy as a result of this characteristic activity in the radio part of the electromagnetic spectrum.

Full Story: http://www.nasa.gov/mission_pages/hubble/science/4c7308.html

NASA Rover Providing New Weather And Radiation Data About Mars

November 21, 2012 Leave a comment

Observations of wind patterns and natural radiation patterns on Mars by NASA’s Curiosity rover are helping scientists better understand the environment on the Red Planet’s surface.

Researchers using the car-sized mobile laboratory have identified transient whirlwinds, mapped winds in relation to slopes, tracked daily and seasonal changes in air pressure, and linked rhythmic changes in radiation to daily atmospheric changes. The knowledge being gained about these processes helps scientists interpret evidence about environmental changes on Mars that might have led to conditions favorable for life.

During the first 12 weeks after Curiosity landed in an area named Gale Crater, an international team of researchers analyzed data from more than 20 atmospheric events with at least one characteristic of a whirlwind recorded by the Rover Environmental Monitoring Station (REMS) instrument. Those characteristics can include a brief dip in air pressure, a change in wind direction, a change in wind speed, a rise in air temperature or a dip in ultraviolet light reaching the rover. Two of the events included all five characteristics.

Full Story: http://www.nasa.gov/mission_pages/msl/news/msl20121115.html

NASA Great Observatories Find Candidate For Most Distant Object In The Universe To Date

November 21, 2012 1 comment

Credit: NASA, ESA, and M. Postman and D. Coe (STScI) and CLASH Team

By combining the power of NASA’s Hubble and Spitzer space telescopes and one of nature’s own natural “zoom lenses” in space, astronomers have set a new record for finding the most distant galaxy seen in the universe.

The farthest galaxy appears as a diminutive blob that is only a tiny fraction of the size of our Milky Way galaxy. But it offers a peek back into a time when the universe was 3 percent of its present age of 13.7 billion years.The newly discovered galaxy, named MACS0647-JD, was observed 420 million years after the big bang, the theorized beginning of the universe. Its light has traveled 13.3 billion years to reach Earth.

This find is the latest discovery from a program that uses natural zoom lenses to reveal distant galaxies in the early universe. The Cluster Lensing And Supernova Survey with Hubble (CLASH),an international group led by Marc Postman of the Space Telescope Science Institute in Baltimore, Md., is using massive galaxy clusters as cosmic telescopes to magnify distant galaxies behind them. This effect is called gravitational lensing.

Full Story: http://www.nasa.gov/mission_pages/hubble/science/distance-record.html
Also: http://hubblesite.org/newscenter/archive/releases/2012/36
Also: http://www.spacetelescope.org/news/heic1217/

Born-Again Star Foreshadows Fate Of Solar System

November 21, 2012 Leave a comment

Credit: NASA/ESA Hubble Space Telescope and X-ray data from ESA’s XMM-Newton and NASA’s Chandra space telescopes

Astronomers have found evidence for a dying Sun-like star coming briefly back to life after casting its gassy shells out into space, mimicking the possible fate our own Solar System faces in a few billion years. This new picture of the planetary nebula Abell 30, located 5500 light-years from Earth, is a composite of visible images.

‘Planetary nebula’ is the name given to the often-concentric shells of stellar material cast into space by dying stars. To astronomers of the 18th century, these objects looked like the colourful ‘blob’ of a planet through their telescopes, and the name stuck.

Astronomers now know that as a star with less than eight times the mass of the Sun swells into a red giant towards the end of its life, its outer layers are expelled via pulsations and winds.

Full Story: http://www.esa.int/esaSC/SEM0UBGPI9H_index_0.html
Also: http://chandra.si.edu/photo/2012/a30/

Rare Image Of Super-Jupiter Sheds Light On Planet Formation

November 21, 2012 Leave a comment

Image credit:
NAOJ / Subaru / J. Carson (College of Charleston) / T. Currie (University Toronto)

An infrared imaging search with the Subaru telescope has captured a rare image of a “Super-Jupiter” around the massive star κ Andromedae. The gas giant has a mass about 13 times that of Jupiter, while the host star has a mass 2.5 times that of the Sun. There are strong indications that this planet formed in a manner similar to ordinary, lower-mass exoplanets: in a “protoplanetary disk” of gas and dust that surrounded the newborn star. This makes the planet an important test case for current models of planet formation and their predictions about planets around massive stars.

Full Story http://www.mpia.de/Public/menu_q2e.php?Aktuelles/PR/2012/PR121119/PR_121119_en.html