* Astronomy

Blobrana · L

RE: Dust

Blobrana · L

Astronomers have torn aside an enshrouding veil of dust to reveal that the universe is twice as brilliant and fiery a place as we had previously imagined.
In one of those profound discoveries that can shift our perception of the universe, an international team of astrophysicists has demonstrated that there is double the amount of light in the universe than previously thought, but that half of it is masked by clouds of interstellar dust.
The discovery, founded on a 10-year survey of some 10,000 galaxies, has been published in Astrophysical Journal Letters.

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Blobrana · L

Anyone gazing up on a dark clear night is greeted by the spectacle of thousands of powerful fusion reactors - the stars. These balls of extremely hot gas are generating unimaginably large quantities of energy. Even the stars within a cube of "only" one light year on a side, taken at a random position in the universe, generate on average 40 quadrillion kilowatthours in one year. This would be enough to meet the current energy consumption needs of mankind 300 times over. Even so, it now appears that from our vantage point we are only registering about half the total energy released by stars in our part of the universe; the other half is being absorbed by miniscule particles of dust floating in the vast expanses of interstellar space within galaxies. This is the conclusion reached by a team of astrophysicists from institutes around the world, including the Max Planck Institute for Nuclear Physics in Heidelberg. The results have implications for our understanding of the creation and evolution of galaxies through cosmic history (The Astrophysical Journal, 10 May 2008).

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Blobrana · L

Astronomers from UK Universities working with colleagues from Germany and Australia have calculated that the Universe is actually twice as bright as previously thought. In the latest Astrophysical Journal Letters (10th May), the astronomers describe how dust is obscuring approximately half of the light that the Universe is currently generating.

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Blobrana · L

There is more to a grain of dust than meets the eye, at least for astronomers as they attempt to probe deeper into distant galaxies. Until now dust has been a nuisance because it has obscured galaxies, and the stars within them, by absorbing the radiation they emit. But more recently dust has started to present opportunities because it emits radiation itself as a consequence of being heated up by nearby stars. Aided by new observing instruments and sophisticated computer software, this radiation enables astronomers to reconstruct what lies behind the dust. Furthermore the dust itself plays a vital role in star formation within galaxies.
The stage was set for dramatic advances in the study of galactic dust in a recent workshop funded by the European Science Foundation (ESF)'s Exploratory Workshop. The big breakthrough is the ability to detect the dust at much higher resolution from its infrared radiation, according to Simone Bianchi from the INAF-IRA in Italy and a co-convenor of the ESF workshop.

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Blobrana · L

Astronomers have taken a baby step in trying to answer the cosmic question of where we come from.
Planets and much on them, including humans, come from dust - mostly from dying stars. But where did the dust that helped form those early stars come from?

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Blobrana · L

Like enormous jewel factories in the sky, the chaotic environments around some supermassive black holes crank out prodigious amounts of glass, rubies and sapphires, a new study finds.
The inevitable breakdown of these materials into simpler components could account for much of the space dust in the universe dust that is recycled to make stars, planets, and life.
Traces of these minerals, as well as sand and marble, were recently found by scientists analysing light from the region around a nearby supermassive black hole using NASA's Spitzer Space Telescope.

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Blobrana · L

The hit song that proclaimed, "All we are is dust in the wind," may have some cosmic truth to it. New findings from NASA's Spitzer Space Telescope suggest that space dust -- the same stuff that makes up living creatures and planets -- was manufactured in large quantities in the winds of black holes that populated our early universe.
The findings are a significant new clue in an unsolved mystery: where did all the dust in the young universe originate?

"We were surprised to find what appears to be freshly made dust entrained in the winds that blow away from supermassive black holes. This could explain where the dust came from that was needed to make the first generations of stars in the early universe" - Ciska Markwick-Kemper of the University of Manchester, U.K. Markwick-Kemper is lead author of a new paper appearing in an upcoming issue of the Astrophysical Journal Letters.

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