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New Study Maps Space Dust in 3-D

...a new study led by Edward F. Schlafly, a Hubble Fellow in the Physics Division at the Department of Energys Lawrence Berkeley National Laboratory (Berkeley Lab), is providing a detailed, 3-D look at dust on a scale spanning thousands of light-years in our Milky Way galaxy. The study was published today in The Astrophysical Journal.
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Cosmic popcorn effect helps space dust survive our atmosphere

Like tiny skydivers, particles of space dust use water to "parachute" safely to Earth. This helps wet particles withstand the plunge to Earth better than dry ones, meaning we may be overestimating the wetness of nearby asteroids.
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Title: The sudden appearance of dust in the early Universe
Author: Lars Mattsson

Observations suggest that high-redshift galaxies are either very dusty or essentially dust free. The evolution from one regime to the other must also be very fast, since evolved and dusty galaxies show up at redshifts corresponding to a Universe which is only about 500 Myr old. In the present paper models which predicts the existence of an apparent dichotomy between dusty and dust-free galaxies at high redshift are considered. Galaxies become dusty as soon as they reach an evolved state and the transition is very rapid. A special case suggests that while stellar dust production is overall relatively insignificant -- contrary to what has been argued recently -- it can at the same time be consistent with efficient dust production in supernovae in the local Universe. Special attention will be given to the recent discovery of a dusty normal galaxy (A1689-zD1) at a very high redshift z = 7.5 0.2.

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Title: Dust production 680-850 million years after the Big Bang
Author: Michal J. Michalowski (IfA, Edinburgh)

Dust plays an important role in our understanding of the Universe, but it is not obvious yet how the dust in the distant universe was formed. I derived the dust yields per asymptotic giant branch (AGB) star and per supernova (SN) required to explain dust masses of galaxies at z = 6.3-7.5 (680-850 million years after the Big Bang) for which dust emission has been detected (HFLS3 at z = 6.34, ULAS J1120+0641 at z = 7.085, and A1689-zD1 at z = 7.5), or unsuccessfully searched for. I found very high required yields, implying that AGB stars could not contribute substantially to dust production at these redshifts, and that SNe could explain these dust masses, but only if they do not destroy majority of the dust they form (which is unlikely given the upper limits on the SN dust yields derived for dust non-detected galaxies). This suggests that the grain growth in the interstellar medium is likely required at these early epochs.

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Pitch Black: Cosmic Clumps Cast the Darkest Shadows

Astronomers have found cosmic clumps so dark, dense and dusty that they throw the deepest shadows ever recorded. Infrared observations from NASA's Spitzer Space Telescope of these blackest-of-black regions paradoxically light the way to understanding how the brightest stars form.
The clumps represent the darkest portions of a huge, cosmic cloud of gas and dust located about 16,000 light-years away. A new study takes advantage of the shadows cast by these clumps to measure the cloud's structure and mass.
The dusty cloud, results suggest, will likely evolve into one of the most massive young clusters of stars in our galaxy. The densest clumps will blossom into the cluster's biggest, most powerful stars, called O-type stars, the formation of which has long puzzled scientists. These hulking stars have major impacts on their local stellar environments while also helping to create the heavy elements needed for life.

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All galaxies got dusty 800 million years after Big Bang

Researchers at the University of Texas at Austin are pursuing one of the largest Hubble Space Telescope projects to date, studying dust in thousands of galaxies over a wide range of cosmic time
Understanding how cosmic dust forms over time is an integral step in figuring out the evolution of galaxies, and the stars and planets within them.

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Birth of a Planet

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Title: A close halo of large transparent grains around extreme red giant stars
Authors: Barnaby R. M. Norris, Peter G. Tuthill, Michael J. Ireland, Sylvestre Lacour, Albert A. Zijlstra, Foteini Lykou, Thomas M. Evans, Paul Stewart, Timothy R. Bedding

Intermediate-mass stars end their lives by ejecting the bulk of their envelope via a slow dense wind back into the interstellar medium, to form the next generation of stars and planets. Stellar pulsations are thought to elevate gas to an altitude cool enough for the condensation of dust, which is then accelerated by radiation pressure from starlight, entraining the gas and driving the wind. However accounting for the mass loss has been a problem due to the difficulty in observing tenuous gas and dust tens of milliarcseconds from the star, and there is accordingly no consensus on the way sufficient momentum is transferred from the starlight to the outflow. Here, we present spatially-resolved, multi-wavelength observations of circumstellar dust shells of three stars on the asymptotic giant branch of the HR diagram. When imaged in scattered light, dust shells were found at remarkably small radii (<~ 2 stellar radii) and with unexpectedly large grains (~300 nm radius). This proximity to the photosphere argues for dust species that are transparent to starlight and therefore resistant to sublimation by the intense radiation field. While transparency usually implies insufficient radiative pressure to drive a wind, the radiation field can accelerate these large grains via photon scattering rather than absorption - a plausible mass-loss mechanism for lower-amplitude pulsating stars.

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Astronomers discover sandstorms in space

Astronomers at The University of Manchester believe they have found the answer to the mystery of a powerful 'superwind' which causes the death of stars.
Writing in Nature, the team of researchers used new techniques which allowed them to look into the atmospheres of distant, dying stars.
The team, lead by Barnaby Norris from the University of Sydney in Australia, includes scientists from the Universities of Manchester, Paris-Diderot, Oxford and Macquarie University, New South Wales. They used the Very Large Telescope in Chile, operated by the European Southern Observatory.

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Ferocious superwind will seal sun's doom

Superwinds were already known to exist, but it was not clear how they could be powered. One idea was that iron-tainted dust might absorb starlight to be pushed outwards. The problem with that model is that the dust would heat up and vaporise before it could really get moving and drive the wind.
Zijlstra's team used the Very Large Telescope in Chile to look at three red giant stars that are in this late stage of life. By using polarisers and masking off parts of the telescope, they could pick out the polarised light coming from shells of dust around each star.
The dust was so close to these stars that it would certainly be vaporised if it were absorbing light strongly. So it must be made of transparent crystals. The team suspect it is made of clear silicate minerals, similar to ordinary terrestrial sand grains.

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Stardust recycling mystery solved

A long-standing mystery about how dying stars spew out the material of future planets is now solved, scientists say.
While stars like our Sun are known to eject much of their mass in their final years, it has remained unclear just how the dust is blown away.
Scientists reporting in Nature describe an astronomical study of extraordinary resolution to tackle the mystery.
They found dust grains of nearly a millionth of a metre across, big enough to be pushed out by dying stars' light.

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