Free Newsletters - Space - Defense - Environment - Energy - Solar - Nuclear
..
. 24/7 Space News .




STELLAR CHEMISTRY
Starbirth Surprisingly Energetic: ALMA observations give new insights into protostars
by Staff Writers
Charlottesville VA (SPX) Aug 26, 2013


ALMA image of a protostar blowing material from the surrounding cloud of dust and gas. The ALMA data (red and blue) show the star's outflow superimposed on an optical (Digital Sky Survey) image of the surrounding cloud. The outflow material is moving at much larger speeds than seen before. Credit: Bill Saxton; NRAO/AUI/NSF; SDSS.

While observing a newborn star, astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) telescope discovered twin jets of matter blasting out into space at record-breaking speed. These surprisingly forceful molecular "winds" could help refine our understanding of how stars impact their cloudy nurseries and shape their emerging stellar systems.

During their formative years, stars both take in and blast away tremendous amounts of matter. When this ejected material collides with the surrounding gas it glows, forming what is known as a Herbig-Haro (HH) object. This give-and-take can greatly impact the way a stellar system evolves and also reshape the surrounding nebula of dust and gas from which either single or whole families of stars form.

By studying one such stellar neighborhood, dubbed HH 46/47, the international team of astronomers uncovered high-velocity streams of carbon monoxide (CO) molecules flowing away from a star buried deep within its cloudy stellar nursery.

ALMA's superb sensitivity and the orientation of the star enabled the researchers to detect two jets of CO, when only one had ever been seen before. The data also revealed that this material was rushing along at 40 kilometers per second, which is 3 to 4 times faster than seen in previous CO observations.

"The ALMA data reveal molecular gas close to the protostar at velocities much higher that ever observed from such an object," said Hector Arce from Yale University, the principal investigator on this study. "This means that this rapidly fleeing gas carries much more energy and momentum than previously thought, which could significantly impact the evolution of this emerging stellar system."

The star, which is located 1,400 light-years away in the constellation Vela, is relatively young -- on the order of a few hundred thousand years. The astronomers speculate that it is not significantly different from what our infant Sun would have looked like, though a little less massive.

In their youth, stars bulk-up by drawing in material from a surrounding disk of dust and gas. A portion of this material, however, gets diverted and caught-up in the star's magnetic fields causing it to be spewed out as jets from the stars' north and south poles.

Since there is a direct relationship between the jets and a star's accretion disk, there is a great deal to be learned about stellar formation by simply studying the jets.

ALMA discovered the high-velocity outflowing gas hidden within very wide-angle winds. The data also revealed that the surrounding cloud material was being pushed and accelerated by the winds. Since this is a normal, not very special protostar, the astronomers believe that the same features can be found elsewhere. If so, Arce speculates, astronomers would have to change their view on how much impact these outflows have. "If it has lots of energy, it can clear surrounding gas, leaving just the star and its surrounding disk of planet-forming dust and gas," said Arce.

These new observations also suggest that there have been episodes of outflow followed by quieter, less active periods. This would mean that there has also been episodic accretion of material onto the star.

Diego Mardones, a co-author on the study with the University of Chile, emphasizes that "this system is similar to most isolated low mass stars during their formation and birth. But it is also unusual because the outflow impacts the cloud directly on one side of the young star and escapes out of the cloud on the other. This makes it an excellent system for studying the impact of the stellar winds on the parent cloud from which the young star formed."

"The detail in the Herbig-Haro 46/47 images is stunning. Perhaps more stunning is the fact that, for these types of observations, we really are still in the early days. In the future, ALMA will provide even better images than this in a fraction of the time," adds Stuartt Corder with the National Radio Astronomy Observatory (NRAO), a co-author on the new paper.

The results are published in the Astrophysical Journal. The paper is available here

.


Related Links
Atacama Large Millimeter/submillimeter Array (ALMA)
Stellar Chemistry, The Universe And All Within It






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





STELLAR CHEMISTRY
A brighter method for measuring the surface gravity of distant stars
Nashville TN (SPX) Aug 23, 2013
Astronomers have found a clever new way to slice and dice the flickering light from a distant star in a way that reveals the strength of gravity at its surface. That is important because a star's surface gravity is one of the key properties that astronomers use to calculate a star's physical properties and assess its evolutionary state. The new technique can also be used to significa ... read more


STELLAR CHEMISTRY
NASA Prepares for First Virginia Coast Launch to Moon

NASA Selects Launch Services Contract for OSIRIS-REx Mission

Environmental Controls Move Beyond Earth

Bad night's sleep? The moon could be to blame

STELLAR CHEMISTRY
We may all be Martians

Mars Curiosity Debuts Autonomous Navigation

Scouting a Boulder Field

ASA Mars Rover Views Eclipse of the Sun by Phobos

STELLAR CHEMISTRY
NASA awards nearly $1.5B in support contracts

NSBRI and NASA Reduce Space Radiation Risks by Soliciting for Center of Space Radiation Research

Next Generation of Explorers Takes the Stage

Has Voyager 1 Left The Solar System?

STELLAR CHEMISTRY
China to launch lunar lander by end of year: media

China launches three experimental satellites

Medical quarantine over for Shenzhou-10 astronauts

China's astronauts ready for longer missions

STELLAR CHEMISTRY
Cosmonauts Complete Spacewalk, Unfold Russian Flag in Space

Italian astronaut recounts spacewalk drowning terror

ISS Boosting Biological Research in Orbit

Japanese Cargo Craft Captured, Berthed to ISS

STELLAR CHEMISTRY
Ariane 5 build-up is completed for Arianespace upcoming flight with EUTELSAT

Russian rocket engine export ban could halt US space program

The go-ahead is given for Ariane 5 mission to orbit EUTELSAT 25B/Es'hail 1 and GSAT-7

Arianespace Launches EUTELSAT 25B/Es'hail 1 and GSAT 7

STELLAR CHEMISTRY
Waking up to a new year

Study: Planets might be 'born free' without a parent star

Distant planet sets speed record by orbiting its star every 8.5 hours

Kepler planet hunter spacecraft is beyond repair: NASA

STELLAR CHEMISTRY
Space Laser To Prove Increased Broadband Possible

Computer Simulations Indicate Calcium Carbonate Has a Dense Liquid Phase

Creating a Secure, Private Internet and Cloud at the Tactical Edge

Sticking power of plant polyphenols used in new coatings




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement