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Posts Tagged ‘cosmic dust’

NASA’s WISE Spacecraft Discovers Most Luminous Galaxy In Universe

May 21, 2015 1 comment

Artist's concept. Image credit: N/A

Artist’s concept. Image credit: N/A

A remote galaxy shining with the light of more than 300 trillion suns has been discovered using data from NASA’s Wide-field Infrared Survey Explorer (WISE). The galaxy is the most luminous galaxy found to date and belongs to a new class of objects recently discovered by WISE — extremely luminous infrared galaxies, or ELIRGs.

“We are looking at a very intense phase of galaxy evolution,” said Chao-Wei Tsai of NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, lead author of a new report appearing in the May 22 issue of The Astrophysical Journal. “This dazzling light may be from the main growth spurt of the galaxy’s black hole.

The brilliant galaxy, known as WISE J224607.57-052635.0, may have a behemoth black hole at its belly, gorging itself on gas. Supermassive black holes draw gas and matter into a disk around them, heating the disk to roaring temperatures of millions of degrees and blasting out high-energy, visible, ultraviolet, and X-ray light. The light is blocked by surrounding cocoons of dust. As the dust heats up, it radiates infrared light.

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Cosmic Forecast: Dark Clouds Will Give Way To Sunshine

September 3, 2014 Leave a comment

Credit: ESO

Credit: ESO

Lupus 4, a spider-shaped blob of gas and dust, blots out background stars like a dark cloud on a moonless night in this intriguing new image. Although gloomy for now, dense pockets of material within clouds such as Lupus 4 are where new stars form and where they will later burst into radiant life. The Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile captured this new picture.

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New Milky Way Maps Help Solve Stubborn Interstellar Material Mystery

August 14, 2014 Leave a comment

An international team of sky scholars, including a key researcher from Johns Hopkins, has produced new maps of the material located between the stars in the Milky Way. The results should move astronomers closer to cracking a stardust puzzle that has vexed them for nearly a century.

The maps and an accompanying journal article appear in the Aug. 15 issue of the journal Science. The researchers say their work demonstrates a new way of uncovering the location and eventually the composition of the interstellar medium—the material found in the vast expanse between star systems within a galaxy.

This material includes dust and gas composed of atoms and molecules that are left behind when a star dies. The material also supplies the building blocks for new stars and planets.

“There’s an old saying that ‘We are all stardust,’ since all chemical elements heavier than helium are produced in stars,” said Rosemary Wyse, a Johns Hopkins professor of physics and astronomy who played a prominent role in the research and helped shape the Science paper. “But we still don’t know why stars form where they do. This study is giving us new clues about the interstellar medium out of which the stars form.”

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Stardust Discovers Potential Interstellar Space Particles

August 14, 2014 Leave a comment

Seven rare, microscopic interstellar dust particles that date to the beginnings of the solar system are among the samples collected by scientists who have been studying the payload from NASA’s Stardust spacecraft since its return to Earth in 2006. If confirmed, these particles would be the first samples of contemporary interstellar dust.

A team of scientists has been combing through the spacecraft’s aerogel and aluminum foil dust collectors since Stardust returned in 2006.The seven particles probably came from outside our solar system, perhaps created in a supernova explosion millions of years ago and altered by exposure to the extreme space environment. The particles would be the first confirmed samples of contemporary interstellar dust.

The research report appears in the Aug. 15 issue of the journal Science. Twelve other papers about the particles will appear next week in the journal Meteoritics & Planetary Science.

“These are the most challenging objects we will ever have in the lab for study, and it is a triumph that we have made as much progress in their analysis as we have,” said Michael Zolensky, curator of the Stardust laboratory at NASA’s Johnson Space Center in Houston and coauthor of the Science paper.

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The Laws That Determine How Dust Affects The Light That Reaches Us From The Stars Are Being Rewritten


Credit: NASA, N. Walborn, J. Maíz-Apellániz and R. Barbá

Credit: NASA, N. Walborn, J. Maíz-Apellániz and R. Barbá

If the space traversed by light to reach our eyes were empty, knowing the properties of a star could be as simple as taking a picture of it and measuring its glow (something known as photometry). But the interstellar environment is strewn with dust that absorbs and scatters light, making objects look less luminous and redder—or colder—than they actually are. A recently published paper makes it possible, at last, to correct this distorting effect adequately.

“In the range of wavelengths that our eyes perceive -the visible light- of every billion photons that a star in the centre of the Milky Way emits, only one reaches our eyes,” says Jesús Maíz Apellániz, researcher at the Institute of Astrophysics of Andalusia (IAA-CSIC) in charge of the publication. “This is an extreme example of how dust affects the light of stars, a phenomenon that takes place in every single environment, albeit with less intensity.”

The effect of dust, then, must be reckoned with in any astronomical observation before trying to extract the characteristics of an object. Maíz Apellániz, together with an international team of collaborators, showed that the laws used since 1989 to calculate the extinction of light produced by dust had serious limitations and yielded, among others, erroneous temperature estimates for stars. So they took it upon themselves to change those laws.

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Molecular Hydrogen Formation Makes Dust Spin

October 3, 2013 Leave a comment

In a paper published in the Oct. 1, 2013, issue of The Astrophysical Journal, an integrated team of observers and theoreticians led by USRA astronomer Dr. B-G Andersson, has used telescopes in Spain, Hawaii, Arizona, and New Mexico, to show – for the first time – that intense molecular hydrogen (H2) formation leads to an increase in the amount of polarization seen when starlight passes through dust clouds in the interstellar medium.

“While interstellar polarization has been known since 1949, the physical mechanisms behind grain alignment have been poorly understood until recently,” said Dr. Andersson. “These observations form part of a coordinated effort to – after more than 60 years – place interstellar grain alignment on a solid theoretical and observational footing.”

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Cosmic Dust Belts Without Dust


Planets and asteroids, red giants and brown dwarfs – there are all kinds of objects in our Universe. Debris disks are among them. These are belts consisting of countless dust particles and planetesimals, circling around one central star. “At least one fifth of stars are surrounded by dust belts like these,” Prof. Dr. Alexander Krivov from the Friedrich-Schiller-University Jena explains. “They are the remains of the formation of planets, in which the unused, building materials are collected,” the astrophysicist points out. Therefore debris disks are an important piece in the puzzle to be able to better understand the variety of planetary systems.

For astronomers like Alexander Krivov debris disks are actually nothing new. Our sun is also orbited by such dust belts: the Asteroid Belt and the Kuiper Belt with Pluto being perhaps the most well-known object in it. However, the Jena astrophysicist, accompanied by an international team of scientists, has observed six stars similar to the sun with extraordinary dust belts: The newly discovered debris disks are not only bigger than the Kuiper Belt. Above all they are extremely cold. With a temperature of about minus 250 °C they are the coldest debris disks known so far. The scientists report on it in the science journal ‘The Astrophysical Journal’, which is already online and will be available in a print version from 20 July. “We were surprised that such cold debris disks exist at all,” Alexander Krivov, the lead author of the new study, says. By way of comparison: The Kuiper Belt is about 70 °C degree warmer, some of the dust disks even reach room temperature.

Full Story: http://www.uni-jena.de/en/News/PM130708_krivov_debris_disks.html