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Posts Tagged ‘ESO’

A Close Look At The Toby Jug Nebula

October 9, 2013 Leave a comment

Credit: ESO

Credit: ESO

Located about 1200 light-years from Earth in the southern constellation of Carina (The Ship’s Keel), the Toby Jug Nebula, more formally known as IC 2220, is an example of a reflection nebula. It is a cloud of gas and dust illuminated from within by a star called HD 65750. This star, a type known as a red giant, has five times the mass of our Sun but it is in a much more advanced stage of its life, despite its comparatively young age of around 50 million years.

The nebula was created by the star, which is losing part of its mass out into the surrounding space, forming a cloud of gas and dust as the material cools. The dust consists of elements such as carbon and simple, heat-resistant compounds such as titanium dioxide and calcium oxide (lime). In this case, detailed studies of the object in infrared light point to silicon dioxide (silica) being the most likely compound reflecting the star’s light.

IC 2220 is visible as the star’s light is reflected off the grains of dust. This celestial butterfly structure is almost symmetrical, and spans about one light-year. This phase of a star’s life is short-lived and such objects are thus rare.

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Final Antenna Delivered to ALMA

October 3, 2013 Leave a comment

Credit: ESO/C. Pontoni

Credit: ESO/C. Pontoni

The final antenna for the Atacama Large Millimeter/submillimeter Array (ALMA) project has just been handed over to the ALMA Observatory. The 12-metre-diameter dish was manufactured by the European AEM Consortium and also marks the successful delivery of a total of 25 European antennas — the largest ESO contract so far.

The antenna is the 66th and final antenna to be delivered to the observatory. North America has provided 25 12-metre antennas, while East Asia has delivered 16 (four 12-metre and twelve 7-metre). By the end of 2013, all 66 ultra-precise millimetre/submillimetre-wave radio antennas are expected to be working together as one telescope, in an array that will stretch for up to 16 kilometres across the Chajnantor Plateau in the Atacama Desert of northern Chile.

This delivery of the last antenna now completes the ALMA antenna construction phase [1] and provides all 66 antennas for science use, marking the beginning of a new era of discoveries in astronomy. “This is an important milestone for the ALMA Observatory since it enables astronomers in Europe and elsewhere to use the complete ALMA telescope, with its full sensitivity and collecting area,” says Wolfgang Wild, the European ALMA Project Manager.

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Coma Cluster: Clues To The Growth Of The Colossus In Coma

September 19, 2013 Leave a comment

Credit: ESO. Acknowledgement: Martin Pugh

Credit: ESO. Acknowledgement: Martin Pugh

Located around 6000 light-years from Earth in the constellation of Scorpius (The Scorpion), the nebula formally known as IC 4628 is a huge region filled with gas and clumps of dark dust. These gas clouds are star-forming regions, producing brilliant hot young stars. In visible light, these stars appear as a blue-white colour, but they also emit intense radiation in other parts of the spectrum — most notably in the ultraviolet.

It is this ultraviolet light from the stars that causes the gas clouds to glow. This radiation strips electrons from hydrogen atoms, which then later recombine and release energy in the form of light. Each chemical element emits light at characteristic colours when this process occurs, and for hydrogen the predominant colour is red. IC 4628 is an example of an HII region.

Over the last few million years this region of sky has formed many stars, both individually and in clusters. There is a large scattered star cluster named Collinder 316 which extends over most of this image. This cluster is a part of a much larger gathering of very hot and luminous stars. Also visible are many dark structures or cavities, where interstellar matter has been blown away by the powerful winds generated by the nearby hot stars.

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Oldest Solar Twin Identified

August 28, 2013 Leave a comment

Astronomers have only been observing the Sun with telescopes for 400 years — a tiny fraction of the Sun’s age of 4.6 billion years. It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives. Now astronomers have identified a star that is essentially an identical twin to our Sun, but 4 billion years older — almost like seeing a real version of the twin paradox in action.

Jorge Melendez (Universidade de São Paulo, Brazil), the leader of the team and co-author of the new paper explains: “For decades, astronomers have been searching for solar twins in order to know our own life-giving Sun better. But very few have been found since the first one was discovered in 1997. We have now obtained superb-quality spectra from the VLT and can scrutinise solar twins with extreme precision, to answer the question of whether the Sun is special.”

Full Story: http://www.eso.org/public/news/eso1337/

Two Very Different Gas Clouds In The Galaxy Next Door


Credit: ESO

Credit: ESO

ESO’s Very Large Telescope has captured an intriguing star-forming region in the Large Magellanic Cloud — one of the Milky Way’s satellite galaxies. This sharp image reveals two distinctive glowing clouds of gas: red-hued NGC 2014, and its blue neighbour NGC 2020. While they are very different, they were both sculpted by powerful stellar winds from extremely hot newborn stars that also radiate into the gas, causing it to glow brightly.

This image was taken by the Very Large Telescope (VLT) at ESO’s Paranal Observatory in Chile — the best place in the southern hemisphere for astronomical observing. But even without the help of telescopes like the VLT, a glance towards the southern constellation of Dorado (The Swordfish or Dolphinfish [1]) on a clear, dark night reveals a blurry patch which, at first sight, appears to be just like a cloud in the Earth’s atmosphere.

At least, this may have been explorer Ferdinand Magellan’s first impression during his famous voyage to the southern hemisphere in 1519. Although Magellan himself was killed in the Philippines before his return, his surviving crew announced the presence of this cloud and its smaller sibling when they returned to Europe, and these two small galaxies were later named in Magellan’s honour. However, they were undoubtedly seen by both earlier European explorers and observers in the southern hemisphere, although they were never reported.

Full Story and Images: http://www.eso.org/public/news/eso1335/

Under Leaden Skies – Where Heavy Metal Clouds The Stars


Artist's impression of the surface of HE2359-2844. Images created using POV-Ray by C. S. Jeffery.

Artist’s impression of the surface of HE2359-2844. Images created using POV-Ray by C. S. Jeffery.

In a paper shortly to be published in the Oxford University Press journal Monthly Notices of the Royal Astronomical Society, a team of astronomers from the Armagh Observatory in Northern Ireland report the discovery of two unusual stars with extremely high concentrations of lead in their atmospheres.

Naslim Neelamkodan, Simon Jeffery, Natalie Behara and Alan Hibbert are studying the surfaces of small hot stars, known as helium-rich subdwarfs. They are already known to be peculiar because they contain much less hydrogen and much more helium than normal.

The astronomers studied the stars using observations from the archives of the European Southern Observatory’s Very Large Telescope in Chile.The light signatures, or spectra, of both stars showed a few features which did not match any atoms expected to be present. After some detective work, the team realised that the features were due to lead.

Full Story: http://www.ras.org.uk/news-and-press/224-news-2013/2322-under-leaden-skies

Spitzer Discovers Young Stars With A ‘Hula Hoop’


Artist's impression. Image credit: NASA/JPL-Caltech

Artist’s impression. Image credit: NASA/JPL-Caltech

Astronomers using NASA’s Spitzer Space Telescope have spotted a young stellar system that “blinks” every 93 days. Called YLW 16A, the system likely consists of three developing stars, two of which are surrounded by a disk of material left over from the star-formation process.

As the two inner stars whirl around each other, they periodically peek out from the disk that girds them like a hula hoop. The hoop itself appears to be misaligned from the central star pair, probably due to the disrupting gravitational presence of the third star orbiting at the periphery of the system. The whole system cycles through bright and faint phases, with the central stars playing a sort of cosmic peek-a-boo as the tilted disk twirls around them. It is believed that this disk should go on to spawn planets and the other celestial bodies that make up a solar system.

Spitzer observed infrared light from YLW 16A, emitted by the warmed gas and dust in the disk that still swathes the young stars. Other observations came from the ground-based 2MASS survey, as well as from the NACO instrument at the European Southern Observatory’s Very Large Telescope in Chile.

Full Story: http://www.jpl.nasa.gov/news/news.php?release=2013-236

ALMA Sheds Light On Planet-Forming Gas Streams


Artist’s impression. Credit: ESO/L. Calçada/ESA/AOES Medialab

Artist’s impression. Credit: ESO/L. Calçada/ESA/AOES Medialab

Astronomers using ESO’s Very Large Telescope have spotted a distant galaxy hungrily snacking on nearby gas. Gas is seen to fall inwards towards the galaxy, creating a flow that both fuels star formation and drives the galaxy’s rotation. This is the best direct observational evidence so far supporting the theory that galaxies pull in and devour nearby material in order to grow and form stars. The results will appear in the 5 July 2013 issue of the journal Science.

Astronomers have always suspected that galaxies grow by pulling in material from their surroundings, but this process has proved very difficult to observe directly. Now ESO’s Very Large Telescope has been used to study a very rare alignment between a distant galaxy and an even more distant quasar — the extremely bright centre of a galaxy powered by a supermassive black hole. The light from the quasar passes through the material around the foreground galaxy before reaching Earth, making it possible to explore in detail the properties of the gas around the galaxy. These new results give the best view so far of a galaxy in the act of feeding.

“This kind of alignment is very rare and it has allowed us to make unique observations,” explains Nicolas Bouché of the Research Institute in Astrophysics and Planetology (IRAP) in Toulouse, France, lead author of the new paper. “We were able to use ESO’s Very Large Telescope to peer at both the galaxy itself and its surrounding gas. This meant we could attack an important problem in galaxy formation: how do galaxies grow and feed star formation?”

Full Story: http://www.eso.org/public/news/eso1330/

Three Planets In Habitable Zone Of Nearby Star

June 26, 2013 1 comment

Artist's impression of the Gliese 667C system. Image Credit: ESO/M. Kornmesser

Artist’s impression of the Gliese 667C system. Image Credit: ESO/M. Kornmesser

A team of astronomers has combined new observations of Gliese 667C with existing data from HARPS at ESO’s 3.6-metre telescope in Chile, to reveal a system with at least six planets. A record-breaking three of these planets are super-Earths lying in the zone around the star where liquid water could exist, making them possible candidates for the presence of life. This is the first system found with a fully packed habitable zone.

Gliese 667C is a very well-studied star. Just over one third of the mass of the Sun, it is part of a triple star system known as Gliese 667 (also referred to as GJ 667), 22 light-years away in the constellation of Scorpius (The Scorpion). This is quite close to us — within the Sun’s neighbourhood — and much closer than the star systems investigated using telescopes such as the planet-hunting Kepler space telescope.

These planets orbit the third fainter star of a triple star system. Viewed from one of these newly found planets the two other suns would look like a pair of very bright stars visible in the daytime and at night they would provide as much illumination as the full Moon. The new planets completely fill up the habitable zone of Gliese 667C, as there are no more stable orbits in which a planet could exist at the right distance to it.

Full Story: http://www.eso.org/public/news/eso1328/
Also: https://carnegiescience.edu/news/one_star_three_habitable_planets
Also: http://www.washington.edu/news/2013/06/25/astronomers-find-three-super-earths-in-nearby-stars-habitable-zone/
Also:http://keckobservatory.org/news/scientists_discover_system_with_three_planets_in_habitable_zone

Dusty Surprise Around Giant Black Hole


Artist’s impression. Credit: ESO/M. Kornmesser

Artist’s impression. Credit: ESO/M. Kornmesser

ESO’s Very Large Telescope Interferometer has gathered the most detailed observations ever of the dust around the huge black hole at the centre of an active galaxy. Rather than finding all of the glowing dust in a doughnut-shaped torus around the black hole, as expected, the astronomers find that much of it is located above and below the torus. These observations show that dust is being pushed away from the black hole as a cool wind — a surprising finding that challenges current theories and tells us how supermassive black holes evolve and interact with their surroundings.

Over the last twenty years, astronomers have found that almost all galaxies have a huge black hole at their centre. Some of these black holes are growing by drawing in matter from their surroundings, creating in the process the most energetic objects in the Universe: active galactic nuclei (AGN). The central regions of these brilliant powerhouses are ringed by doughnuts of cosmic dust dragged from the surrounding space, similar to how water forms a small whirlpool around the plughole of a sink. It was thought that most of the strong infrared radiation coming from AGN originated in these doughnuts.

But new observations of a nearby active galaxy called NGC 3783, harnessing the power of the Very Large Telescope Interferometer (VLTI) at ESO’s Paranal Observatory in Chile [2], have given a team of astronomers a surprise.

Full Story: http://www.eso.org/public/news/eso1327/