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A Planetary Nebula Gallery

October 11, 2012 Leave a comment

Cat’s Eye. Credits: X-ray: NASA/CXC/RIT/J.Kastner et al.; Optical: NASA/STScI

This gallery shows four planetary nebulas from the first systematic survey of such objects in the solar neighborhood made with NASA’s Chandra X-ray Observatory. The planetary nebulas shown here are NGC 6543, also known as the Cat’s Eye, NGC 7662, NGC 7009 and NGC 6826. In each case, X-ray emission from Chandra is colored purple and optical emission from the Hubble Space Telescope is colored red, green and blue.

In the first part of this survey, published in a new paper, twenty one planetary nebulas within about 5000 light years of the Earth have been observed. The paper also includes studies of fourteen other planetary nebulas, within the same distance range, that Chandra had already observed.

A planetary nebula represents a phase of stellar evolution that the Sun should experience several billion years from now. When a star like the Sun uses up all of the hydrogen in its core, it expands into a red giant, with a radius that increases by tens to hundreds of times. In this phase, a star sheds most of its outer layers, eventually leaving behind a hot core that will soon contract to form a dense white dwarf star. A fast wind emanating from the hot core rams into the ejected atmosphere, pushes it outward, and creates the graceful, shell-like filamentary structures seen with optical telescopes.

Full Story: http://www.chandra.harvard.edu/photo/2012/pne/
Also: http://www.nasa.gov/mission_pages/chandra/multimedia/planetary_nebula.html

Large Water Reservoirs At The Dawn Of Stellar Birth

October 11, 2012 Leave a comment

Herschel’s infrared view of part of the Taurus Molecular Cloud. Credits: ESA/Herschel/SPIRE

ESA’s Herschel space observatory has discovered enough water vapour to fill Earth’s oceans more than 2000 times over, in a gas and dust cloud that is on the verge of collapsing into a new Sun-like star.

Stars form within cold, dark clouds of gas and dust – ‘pre-stellar cores’ – that contain all the ingredients to make solar systems like our own.

Water, essential to life on Earth, has previously been detected outside of our Solar System as gas and ice coated onto tiny dust grains near sites of active star formation, and in proto-planetary discs capable of forming alien planetary systems.

The new Herschel observations of a cold pre-stellar core in the constellation of Taurus known as Lynds 1544 are the first detection of water vapour in a molecular cloud on the verge of star formation.

Full Story: http://www.esa.int/esaSC/SEMVAO2S18H_index_0.html

UK Contributes 24 Robotic Arms In Giant Leap Forward In Near-Infrared Astronomy

October 11, 2012 Leave a comment

A new high-tech instrument with 24 robotic arms has crossed the Atlantic from Edinburgh to a mountain top in Chile to address in more detail than ever before, some of the key questions surrounding the beginnings of the Universe, stars and galaxies. KMOS (K-Band Multi Object Spectrometer) has been provisionally accepted by the European Southern Observatory (ESO) after it completed final assembly and testing at the UK Astronomy Technology Centre (UK ATC) in Edinburgh. It will now be fitted to one of the four telescopes which make up the European Southern Observatory’s Very Large Telescope (ESO-VLT) at Paranal in Chile, providing astronomers with a far quicker solution to uncover details about galaxies and their properties.

What makes KMOS unique is its ability to image many galaxies simultaneously either in a cluster or in isolation but in both cases, still see the individual properties of each single galaxy. Until now, each galaxy has had to be identified individually to obtain that information, a process that takes years. KMOS will be able to see the same amount of detail in just two months.

Full Story: http://www.stfc.ac.uk/News%20and%20Events/40007.aspx

CANDELS Team Discovers Dusty Galaxies At Ancient Epoch With Hubble Space Telescope; Tracks Build-Up Of Star- And Planet-Forming Material

October 11, 2012 Leave a comment

Dust is an annoyance in everyday life, but an important building block of stars and planets. As such, astronomers need to understand how cosmic dust forms over time — it’s an integral step in figuring out the evolution of galaxies, and the stars and planets within them.

To better understand cosmic dust, University of Texas at Austin assistant professor Steven Finkelstein and colleagues 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. They published some early results in a paper lead by Finkelstein in a recent issue of The Astrophysical Journal.

“We don’t yet understand how galaxies build up their dust reservoirs,” Finkelstein said. “We know that dust builds up through time, but exactly when the formation of dust begins is unknown.”

Full Story: http://mcdonaldobservatory.org/news/releases/2012/1009

Surprising Spiral Structure Spotted By ALMA: New Observations Reveal The Secrets Of A Dying Star

October 11, 2012 Leave a comment

Credit: ALMA (ESO/NAOJ/NRAO)

A team using the Atacama Large Millimeter/submillimeter Array (ALMA), the most powerful millimetre/submillimetre telescope in the world, has discovered a surprising spiral structure in the gas around the red giant star R Sculptoris. This means that there is probably a previously unseen companion star orbiting the star. The astronomers were also surprised to find that far more material than expected had been ejected by the red giant.

“We’ve seen shells around this kind of star before, but this is the first time we’ve ever seen a spiral of material coming out from a star, together with a surrounding shell,” says the lead author on the paper presenting the results, Matthias Maercker (ESO and Argelander Institute for Astronomy, University of Bonn, Germany).

Because they blow out large amounts of material, red giants like R Sculptoris are major contributors to the dust and gas that provide the bulk of the raw materials for the formation of future generations of stars, planetary systems and subsequently for life.

Full Story: http://www.eso.org/public/news/eso1239/