Subscribe free to our newsletters via your
. 24/7 Space News .




STELLAR CHEMISTRY
VLT clears up dusty mystery
by Staff Writers
Paris (SPX) Jul 11, 2014


This artist's impression shows dust forming in the environment around a supernova explosion. VLT observations have shown that these cosmic dust factories make their grains in a two-stage process, starting soon after the explosion, but continuing long afterwards. Image courtesy ESO/M. Kornmesser.

The origin of cosmic dust in galaxies is still a mystery [1]. Astronomers know that supernovae may be the primary source of dust, especially in the early Universe, but it is still unclear how and where dust grains condense and grow. It is also unclear how they avoid destruction in the harsh environment of a star-forming galaxy. But now, observations using ESO's VLT at the Paranal Observatory in northern Chile are lifting the veil for the first time.

An international team used the X-shooter spectrograph to observe a supernova - known as SN2010jl - nine times in the months following the explosion, and for a tenth time 2.5 years after the explosion, at both visible and near-infrared wavelengths [2]. This unusually bright supernova, the result of the death of a massive star, exploded in the small galaxy UGC 5189A.

"By combining the data from the nine early sets of observations we were able to make the first direct measurements of how the dust around a supernova absorbs the different colours of light," said lead author Christa Gall from Aarhus University, Denmark.

"This allowed us to find out more about the dust than had been possible before."

The team found that dust formation starts soon after the explosion and continues over a long time period. The new measurements also revealed how big the dust grains are and what they are made of. These discoveries are a step beyond recent results obtained using the Atacama Large Millimeter/submillimeter Array (ALMA), which first detected the remains of a recent supernova brimming with freshly formed dust from the famous supernova 1987A (SN 1987A; eso1401).

The team found that dust grains larger than one thousandth of a millimetre in diameter formed rapidly in the dense material surrounding the star. Although still tiny by human standards, this is large for a grain of cosmic dust and the surprisingly large size makes them resistant to destructive processes.

How dust grains could survive the violent and destructive environment found in the remnants of supernovae was one of the main open questions of the ALMA paper, which this result has now answered - the grains are larger than expected.

"Our detection of large grains soon after the supernova explosion means that there must be a fast and efficient way to create them," said co-author Jens Hjorth from the Niels Bohr Institute of the University of Copenhagen, Denmark, and continued: "We really don't know exactly how this happens."

But the astronomers think they know where the new dust must have formed: in material that the star shed out into space even before it exploded. As the supernova's shockwave expanded outwards, it created a cool, dense shell of gas - just the sort of environment where dust grains couldseed and grow.

Results from the observations indicate that in a second stage - after several hundred days - an accelerated dust formation process occurs involving ejected material from the supernova. If the dust production in SN2010jl continues to follow the observed trend, by 25 years after the supernova, the total mass of dust will be about half the mass of the Sun; similar to the dust mass observed in other supernovae such as SN 1987A.

"Previously astronomers have seen plenty of dust in supernova remnants left over after the explosions. But they also only found evidence for small amounts of dust actually being created in the supernova explosions. These remarkable new observations explain how this apparent contradiction can be resolved," concludes Christa Gall.

[1] Cosmic dust consists of silicate and amorphous carbon grains - minerals also abundant on Earth. The soot from a candle is very similar to cosmic carbon dust, although the size of the grains in the soot are ten or more times bigger than typical grain sizes for cosmic grains.

[2] Light from this supernova was first seen in 2010, as is reflected in the name, SN 2010jl. It is classed as a Type IIn supernova. Supernovae classified as Type II result from the violent explosion of a massive star with at least eight times the mass of the Sun. The subtype of a Type IIn supernova - "n" denotes narrow - shows narrow hydrogen lines in its spectra. These lines result from the interaction between the material ejected by the supernova and the material already surrounding the star.

.


Related Links
ESO
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
Cosmic accounting reveals missing light crisis
Pasadena CA (SPX) Jul 11, 2014
Something is amiss in the Universe. There appears to be an enormous deficit of ultraviolet light in the cosmic budget. The vast reaches of empty space between galaxies are bridged by tendrils of hydrogen and helium, which can be used as a precise "light meter." In a recent study published in The Astrophysical Journal Letters, a team of scientists finds that the light from known populations ... read more


STELLAR CHEMISTRY
NASA LRO's Moon As Art Collection Is Revealed

Solar photons drive water off the moon

55-year old dark side of the moon mystery solved

New evidence supporting moon formation via collision of 2 planets

STELLAR CHEMISTRY
Rover Uses Arm to Study Several Rocks and Takes Panoramic Images

ADS complete heat shields for 2016 ExoMars mission

Martian salts must touch ice to make liquid water

First LDSD Test Flight a Success

STELLAR CHEMISTRY
Sun Sends More 'Tsunami Waves' to Voyager 1

Privately funded solar spacecraft to launch in 2016

Space Launch System Core Stage Passes Critical Design Review

Taiwan's tourism revenue hits record high in 2013

STELLAR CHEMISTRY
Chinese moon rover designer shooting for Mars

Yutu designer's bittersweet

Are China's Astronauts Moonbound

Chinese scientists prepare for lunar base life support system

STELLAR CHEMISTRY
Orbital Targets July 11 For ISS Commercial Resupply Mission

Space junk damages ISS US segment

NASA Television Coverage Set for Orbital-2 Mission to Space Station

Spot the Space Station looking at you

STELLAR CHEMISTRY
RUAG Space wins major Ariane 5 payload fairing contract

Final ATV loaded with cargo after integration on Ariane 5

O3b satellites integrated on Arianespace Soyuz for July 10 launch

Russia Launches Rokot Carrier Rocket with Three Satellites

STELLAR CHEMISTRY
Newfound Frozen World Orbits in Binary Star System

Discovery expands search for Earth-like planets

Astronomers discover most Earth-like of all exoplanets

Mega-Earth in Draco Smashes Notions of Planetary Formation

STELLAR CHEMISTRY
ASC Signal Introduces Innovative Carbon-Fiber Antenna

Resolve Supplies Zoom Lenses for NASA Testing

With 'ribbons' of graphene, width matters

Even geckos can lose their grip




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - 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. 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 All images and articles appearing on Space Media Network have been edited or digitally altered in some way. Any requests to remove copyright material will be acted upon in a timely and appropriate manner. Any attempt to extort money from Space Media Network will be ignored and reported to Australian Law Enforcement Agencies as a potential case of financial fraud involving the use of a telephonic carriage device or postal service.