Subscribe to our free daily newsletters
. 24/7 Space News .




Subscribe to our free daily newsletters



STELLAR CHEMISTRY
Winds blowing off a dying star
by Staff Writers
Kyoto, Japan (SPX) Nov 13, 2017


illustration only

Stars like our Sun eject large amounts of gas and dust into space, containing various elements and compounds. Asymptotic giant branch - AGB - phase stars, near their end of life, are particularly significant sources of such substances in our galaxy.

Formation of dust around AGB stars has been considered to play an important role in triggering acceleration of stellar wind, but the detailed mechanism of this acceleration has not been well explained.

And there is yet another conundrum. In space, silicon is ten times more abundant than aluminum. However, many oxygen-rich AGB stars are rich in aluminum oxide dust - the major carrier of aluminum - but poor in silicate dust - the carrier of silicon, which has puzzled researchers: why is aluminum oxide dust so abundant around oxygen-rich AGB stars?

In a paper published in Science Advances, a research team led by Aki Takigawa of Kyoto University have utilized the Atacama Large Millimeter/submillimeter Array - ALMA, as the high spatial-resolution radio interferometer in Chile is known - to obtain detailed images of gas molecules forming dust surrounding an AGB star.

"Previously, there was a limit to how well we could observe dust forming regions close to stars," explains Takigawa. "Now, thanks to the high spatial resolution of ALMA, we can obtain images of gases in these regions in finer detail. So we pointed ALMA toward an aluminum oxide-rich AGB star, W Hydrae."

Gas molecules aluminum monoxide and silicon monoxide - AlO and SiO - eventually form aluminum oxide and silicate dust. The team observed that AlO was distributed within three stellar radii of W Hydrae, which was surprisingly similar to the previously-observed dust distribution.

Meanwhile, SiO was detected beyond five stellar radii, and moreover 70% remained gaseous, without forming into dust.

"These results indicate that as aluminum oxide grows and accumulates near a star, the addition of a small amount of silicate dust may trigger wind acceleration," elaborates Takigawa. "This decreases gas density, suppressing further silicate dust formation."

"This may explain the presence of aluminum-oxide-rich but silicate-poor AGB stars."

These new results shed light not only on the dynamics of gas and dust surrounding stars, but also on the importance of studying both together. The team plans to continue using ALMA to elucidate gas and dust dynamics in the universe.

The paper "Dust formation and wind acceleration around the aluminum oxide-rich AGB star W Hydrae" appeared 1 November 2017 in Science Advances, with doi: 10.1126/sciadv.aao2149

STELLAR CHEMISTRY
The star that would not die
Goleta CA (SPX) Nov 09, 2017
Supernovae, the explosions of stars, have been observed in the thousands and in all cases they marked the death of a star. Astronomers at Las Cumbres Observatory have discovered a remarkable exception - a star that exploded multiple times over a period of more than fifty years. Their observations are challenging existing theories on these cosmic catastrophes. When the supernova, named iPTF ... read more

Related Links
Kyoto University
Stellar Chemistry, The Universe And All Within It


Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once


credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly


paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

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

STELLAR CHEMISTRY
NASA Moves Up Critical Crew Safety Launch Abort Test

Brazil's tech junkies seek healing at digital detox clinic

NanoRacks launches Full External Cygnus Deployer on OA-8 to ISS

The road to Orion's launch

STELLAR CHEMISTRY
The state of commercial spaceports in 2017

Orbital ATK Successfully Tests First Motor Case for Next Generation Launch Vehicle

Orbital ATK launches eighth cargo mission to space

Vega launches Earth observation satellite for Morocco

STELLAR CHEMISTRY
How long can microorganisms live on Mars

NASA Opens $2 Million Third Phase of 3D-Printed Habitat Competition

Insight will carry over two million names to Mars

Opportunity Does a Wheelie and is Back on Solid Footing

STELLAR CHEMISTRY
China's reusable spacecraft to be launched in 2020

Space will see Communist loyalty: Chinese astronaut

China launches three satellites

Mars probe to carry 13 types of payload on 2020 mission

STELLAR CHEMISTRY
Astronaut meets volcano

European Space Week starts in Estonia

New Chinese sat comms company awaits approval

Myanmar to launch own satellite system-2 in 2019: vice president

STELLAR CHEMISTRY
Plasma from lasers can shed light on cosmic rays, solar eruptions

Leonardo tapped by British Royal Air Force for radar testing equipment

A new way to mix oil and water

Building better silk

STELLAR CHEMISTRY
Astronomers See Moving Shadows Around Planet-Forming Star

Scientists find potential 'missing link' in chemistry that led to life on earth

18-Month Twinkle in a Forming Star Suggests a Very Young Planet

Overlooked Treasure: The First Evidence of Exoplanets

STELLAR CHEMISTRY
Jupiter's Stunning Southern Hemisphere

Watching Jupiter's multiple pulsating X-ray Aurora

Help Nickname New Horizons' Next Flyby Target

Juno Aces 8th Science Pass of Jupiter, Names New Project Manager




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






The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news 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. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. 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