Found images: 2015 May

[bystander]

Hubble Revisits Tangled NGC 6240
ESA Hubble Picture of the Week | 2015 May 18

[b][i]Credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (Univ of Virginia, Charlottesville/NRAO/Stony Brook Univ)[/i][/b]

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Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. Hubble previously released an image of this galaxy back in 2008, but the knotted region, shown here in a pinky-red hue at the centre of the galaxies, was only revealed in these new observations from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys.

NGC 6240 lies 400 million light-years away in the constellation of Ophiuchus (The Serpent Holder). This galaxy has an elongated shape with branching wisps, loops and tails. This mess of gas, dust and stars bears more than a passing resemblance to a butterfly and, though perhaps less conventionally beautiful, a lobster.

This bizarrely-shaped galaxy did not begin its life looking like this; its distorted appearance is a result of a galactic merger that occurred when two galaxies drifted too close to one another. This merger sparked bursts of new star formation and triggered many hot young stars to explode as supernovae. A new supernova was discovered in this galaxy in 2013, named SN 2013dc. It is not visible in this image, but its location is indicated here.

At the centre of NGC 6240 an even more interesting phenomenon is taking place. When the two galaxies came together, their central black holes did so too. There are two supermassive black holes within this jumble, spiralling closer and closer to one another. They are currently only some 3000 light-years apart, incredibly close given that the galaxy itself spans 300 000 light-years. This proximity secures their fate as they are now too close to escape each other and will soon form a single immense black hole.

[starsurfer]

Hubble Revisits Tangled NGC 6240
ESA Hubble Picture of the Week | 2015 May 18

[b][i]Credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (Univ of Virginia, Charlottesville/NRAO/Stony Brook Univ)[/i][/b]

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Not all galaxies are neatly shaped, as this new NASA/ESA Hubble Space Telescope image of NGC 6240 clearly demonstrates. Hubble previously released an image of this galaxy back in 2008, but the knotted region, shown here in a pinky-red hue at the centre of the galaxies, was only revealed in these new observations from Hubble’s Wide Field Camera 3 and Advanced Camera for Surveys.

NGC 6240 lies 400 million light-years away in the constellation of Ophiuchus (The Serpent Holder). This galaxy has an elongated shape with branching wisps, loops and tails. This mess of gas, dust and stars bears more than a passing resemblance to a butterfly and, though perhaps less conventionally beautiful, a lobster.

This bizarrely-shaped galaxy did not begin its life looking like this; its distorted appearance is a result of a galactic merger that occurred when two galaxies drifted too close to one another. This merger sparked bursts of new star formation and triggered many hot young stars to explode as supernovae. A new supernova was discovered in this galaxy in 2013, named SN 2013dc. It is not visible in this image, but its location is indicated here.

At the centre of NGC 6240 an even more interesting phenomenon is taking place. When the two galaxies came together, their central black holes did so too. There are two supermassive black holes within this jumble, spiralling closer and closer to one another. They are currently only some 3000 light-years apart, incredibly close given that the galaxy itself spans 300 000 light-years. This proximity secures their fate as they are now too close to escape each other and will soon form a single immense black hole.

Wow that is an incredibly detailed image of this fascinating peculiar galaxy! I knew this galaxy had a Ha outflow similar to the well known ones in M82 and M106 but to see it in such high resolution! Great start to a rainy day!

[starsurfer]

NGC 1084
http://www.spacetelescope.org/images/potw1413a/
Copyright: NASA, ESA, and S. Smartt (Queen's University Belfast)
Acknowledgement: Brian Campbell

[starsurfer]

IsWe 2
http://www.astrodonimaging.com/gallery/ ... ?imgID=272
Copyright: Don Goldman

Click to view full size image

[bystander]

The Dreadful Beauty of Medusa
ESO Photo Release | VLT | 2015 May 20

[b][i]Credit: ESO/VLT/FORS[/i][/b]

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Astronomers using ESO’s Very Large Telescope in Chile have captured the most detailed image ever taken of the Medusa Nebula. As the star at the heart of this nebula made its transition into retirement, it shed its outer layers into space, forming this colourful cloud. The image foreshadows the final fate of the Sun, which will eventually also become an object of this kind.

This beautiful planetary nebula is named after a dreadful creature from Greek mythology — the Gorgon Medusa. It is also known as Sharpless 2-274 and is located in the constellation of Gemini (The Twins). The Medusa Nebula spans approximately four light-years and lies at a distance of about 1500 light-years. Despite its size it is extremely dim and hard to observe.

Medusa was a hideous creature with snakes in place of hair. These snakes are represented by the serpentine filaments of glowing gas in this nebula. The red glow from hydrogen and the fainter green emission from oxygen gas extends well beyond this frame, forming a crescent shape in the sky. The ejection of mass from stars at this stage of their evolution is often intermittent, which can result in fascinating structures within planetary nebulae.

For tens of thousands of years the stellar cores of planetary nebulae are surrounded by these spectacularly colourful clouds of gas [1]. Over a further few thousand years the gas slowly disperses into its surroundings. This is the last phase in the transformation of stars like the Sun before ending their active lives as white dwarfs. The planetary nebula stage in the life of a star is a tiny fraction of its total life span — just as the time a child takes to blow a soap bubble and see it drift away is a brief instant compared to a full human life span.

Harsh ultraviolet radiation from the very hot star at the core of the nebula causes atoms in the outward-moving gas to lose their electrons, leaving behind ionised gas. The characteristic colours of this glowing gas can be used to identify objects. In particular, the presence of the green glow from doubly ionised oxygen ([O III]) is used as a tool for spotting planetary nebulae. By applying appropriate filters, astronomers can isolate the radiation from the glowing gas and make the dim nebulae appear more pronounced against a darker background.

When the green [O III] emission from nebulae was first observed, astronomers thought they had discovered a new element that they dubbed nebulium. They later realised that it was simply a rare wavelength of radiation [2] from an ionised form of the familiar element oxygen.

The nebula is also referred to as Abell 21 (more formally PN A66 21), after the American astronomer George O. Abell, who discovered this object in 1955. For some time scientists debated whether the cloud could be the remnant of a supernova explosion. In the 1970s, however, researchers were able to measure the movement and other properties of the material in the cloud and clearly identify it as a planetary nebula [3].

This image uses data from the FOcal Reducer and low dispersion Spectrograph (FORS) instrument attached to the VLT, which were acquired as part of the ESO Cosmic Gems programme [4].

[starsurfer]

NGC 1261
http://www.chart32.de/index.php/component/k2/item/106
Copyright: CHART32
Processing: Johannes Schedler

Click to view full size image

[starsurfer]

Ou 4
http://www.astrobin.com/58386/
Copyright: Mike Hawtin

[bystander]

Rise of the Milky Way
ESO Picture of the Week | 2015 May 25

[b][i]Credit: Yuri Beletsky/ESO[/i][/b]

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n this image, taken by ESO Photo Ambassador Yuri Beletsky, the control building at the Paranal Observatory can be seen below a rising Milky Way, like the proverbial pot of gold at the end of a celestial rainbow.

This building is a hub for the observatory’s operations, and it is from here that the Very Large Telescope (VLT), the VLT interferometer (VLTI), the VLT Survey Telescope (VST) and VLT Infrared Survey Telescope for Astronomy (VISTA) are controlled and maintained. The team of astronomers, telescope and instrument operators, and engineers is on site 24 hours a day to to run these telescopes and to keep them in top condition.

The control building is located on a “shelf” below the main observing platform at the top of the Paranal Mountain. All functions of the four Unit Telescopes (UTs), the four Auxiliary Telescopes (ATs), the two survey telescopes are controlled from their own areas within the central control room, via a gigantic series of computers.

However, managing the observations is not just a matter of pointing the telescope towards an astronomical target — continuous monitoring of the telescope status is required, as well as making adjustments to the instruments before taking exposures to optimise their function. It is also necessary to transfer and store the large amounts of data generated, as well as check the quality of the incoming results.

Not even the incredible view outside the window is enough to prevent the team from working hard to maintain Paranal’s reputation as one of the world’s most productive and powerful ground-based observatories.

[bystander]

The Most Crowded Place in the Milky Way
ESA Hubble Picture of the Week | 2015 May 25

[b][i]Credit: NASA, ESA[/i][/b]

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This new NASA/ESA Hubble Space Telescope image presents the Arches Cluster, the densest known star cluster in the Milky Way. It is located about 25 000 light-years from Earth in the constellation of Sagittarius (The Archer), close to the heart of our galaxy, the Milky Way. It is, like its neighbour the Quintuplet Cluster, a fairly young astronomical object at between two and four million years old.

The Arches Cluster is so dense that in a region with a radius equal to the distance between the Sun and its nearest star there would be over 100 000 stars!

At least 150 stars within the cluster are among the brightest ever discovered in the the Milky Way. These stars are so bright and massive, that they will burn their fuel within a short time, on a cosmological scale, just a few million years, and die in spectacular supernova explosions. Due to the short lifetime of the stars in the cluster, the gas between the stars contains an unusually high amount of heavier elements, which were produced by earlier generations of stars.

Despite its brightness the Arches Cluster cannot be seen with the naked eye. The visible light from the cluster is completely obscured by gigantic clouds of dust in this region. To make the cluster visible astronomers have to use detectors which can collect light from the X-ray, infrared, and radio bands, as these wavelengths can pass through the dust clouds. This observation shows the Arches Cluster in the infrared and demonstrates the leap in Hubble’s performance since its 1999 image of same object.

[starsurfer]

Sh1-89
http://www.capella-observatory.com/Imag ... Sh1-89.htm
Copyright: Makis Palaiologou, Stefan Binnewies and Josef Pöpsel

Click to view full size image

This is the only nebula in the first edition of the Sharpless catalogue (published in 1953) that isn't included in the second edition (published in 1959).

[starsurfer]

NGC 3631
http://www.karelteuwen.be/photo_page.ph ... 6&album=14
Copyright: Karel Teuwen

The low surface brightness spiral galaxy below and to the left of NGC 3631 is NGC 3657.

[bystander]

A Bubbly Cosmic Celebration
ESO Photo Release | VLT/FORS | 2015 May 27

[b][i]Credit: ESO/VLT/FORS[/i][/b]

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In the brightest region of this glowing nebula called RCW 34, gas is heated dramatically by young stars and expands through the surrounding cooler gas. Once the heated hydrogen reaches the borders of the gas cloud, it bursts outwards into the vacuum like the contents of an uncorked champagne bottle — this process is referred to as champagne flow. But the young star-forming region RCW 34 has more to offer than a few bubbles; there seem to have been multiple episodes of star formation within the same cloud.

This new image from ESO’s Very Large Telescope (VLT) in Chile shows a spectacular red cloud of glowing hydrogen gas behind a collection of blue foreground stars. Within RCW 34 — located in the southern constellation of Vela (The Sails) — a group of massive young stars hide in the brightest region of the cloud. These stars have a dramatic effect on the nebula. Gas exposed to strong ultraviolet radiation — as occurs in the heart of this nebula — becomes ionised, meaning that the electrons have escaped the hydrogen atoms.

Hydrogen is treasured by cosmic photographers because it glows brightly in the characteristic red colour that distinguishes many nebulae and allows them to create beautiful images with bizarre shapes. It is also the raw material of dramatic phenomena such as champagne flow. But ionised hydrogen also has an important astronomical role: it is an indicator of star-forming regions. Stars are born from collapsing gas clouds and therefore abundant in regions with copious amounts of gas, like RCW 34. This makes the nebula particularly interesting to astronomers studying stellar birth and evolution.

Vast amounts of dust within the nebula block the view of the inner workings of the stellar nursery deeply embedded in these clouds. RCW 34 is characterised by extremely high extinction, meaning that almost all of the visible light from this region is absorbed before it reaches Earth. Despite hiding away from direct view, astronomers can use infrared telescopes, to peer through the dust and study the nest of embedded stars.

Looking behind the red colour reveals that there are a lot of young stars in this region with masses only a fraction of that of the Sun. These seem to clump around older, more massive stars at the centre, while only a few are distributed in the outskirts. This distribution has led astronomers to believe that there have been different episodes of star formation within the cloud. Three gigantic stars formed in the first event that then triggered the formation of the less massive stars in their vicinity.

This image uses data from the FOcal Reducer and low dispersion Spectrograph (FORS) instrument attached to the VLT, which were acquired as part of the ESO Cosmic Gems programme.

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NGC 2547
http://www.astrostudio.at/1_Deep%20Sky% ... GC2547.jpg
Copyright: Gerald Rhemann

Click to view full size image

[Guest]

Elephant's Trunk nebula - IC1396 - Hubble palette



Larger pic https://www.flickr.com/photos/93801898@ ... 1/sizes/h/
Copyright Dide van den Heuvel - http://www.didevandenheuvel.eu/ dide.heuvel(at)gmail.com

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NGC 2158
http://www.pbase.com/jshuder/image/158748703
Copyright: Jim Shuder

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Tarantula Nebula (NGC 2070)
http://www.chart32.de/index.php/component/k2/item/114
Copyright: CHART32
Processing: Johannes Schedler

[bystander]

A Fascinating Core
ESA Hubble Picture of the Week | 2015 June 01

[b][i]Credit: ESA/Hubble & NASA[/i][/b]

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This NASA/ESA Hubble Space Telescope image captures the galaxy Messier 84 — also known as NGC 4374 — an object from the Messier catalogue, published in its final version in 1781 by Charles Messier.

This elliptical galaxy was discovered in March 1781 and lies about 60 million light-years away from Earth in the constellation of Virgo (The Virgin). The galaxy is part of the very heavily populated centre of the Virgo Cluster, a cluster which consists of more than 1000 galaxies.

This image does not show the whole galaxy but only its very interesting centre, and is likely to be the best image of the region ever captured. Previous observations using Hubble’s Space Telescope Imaging Spectrograph (STIS) revealed a supermassive black hole in the centre of Messier 84. Astronomers found the supermassive black hole by mapping the motion of the gas and the stars which are caught in its grip.

Next to its interesting centre Messier 84 is also known for its supernovae. Two supernovae have been observed within the galaxy. The first, SN1957 was discovered in 1957 and another, called SN1991bg, was discovered in 1991.

[Guest]

https://flic.kr/p/tEiz9r

[Guest]

NGC 2237 Inside the Rosette nebula by Moonrocks, on Flickr