Starship Asterisk*

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

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The smudge of stars at the centre of this NASA/ESA Hubble Space Telescope image is a galaxy known as UGC 5797. UGC 5797 is an emission line galaxy, meaning that it is currently undergoing active star formation. The result is a stellar population that is constantly being refurbished as massive bright blue stars form. Galaxies with prolific star formation are not only veiled in a blue tint, but are key to the continuation of a stellar cycle.

In this image UGC 5797 appears in front of a background of spiral galaxies. Spiral galaxies have copious amounts of dust and gas — the main ingredient for stars — and therefore often also belong to the class of emission line galaxies.

Spiral galaxies have disc-like shapes that drastically vary in appearance depending on the angle at which they are observed. The collection of spiral galaxies in this frame exhibits this attribute acutely: Some are viewed face-on, revealing the structure of the spiral arms, while the two in the bottom left are seen edge-on, appearing as plain streaks in the sky. There are many spiral galaxies, with varying colours and at different angles sprinkled across this image — just take a look. ...

[i]Credit: ESO/[/i][url=http://colosimophotography.com/][b][i]J. Colosimo[/i][/b][/url]

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In this new image dusk reveals a stunning night sky over ESO’s Paranal Observatory, home to the Very Large Telescope (VLT) — the flagship facility for European ground-based astronomy.

As the Sun sets on the site the Milky Way is shown in magnificent detail. Although it appears to the naked eye as a clouded haze across the sky, the Milky Way consists of 100–400 billion individual stars strung out along its 100 000 light-year extent.

In this image the Milky Way is a backdrop to the Unit Telescope number 4, also known as Yepun. Yepun is Venus in the Mapuche language, the language of the indigenous people from the south of Chile.

Yepun is one of four 8.2-metre telescopes that can be used together as one giant telescope, allowing astronomers to detect details up to 16 times finer than would be possible with the individual telescopes. Together, the VLT has stimulated a new age of discoveries, with several notable scientific firsts, including tracking individual stars moving around the supermassive black hole at the centre of the Milky Way (eso0846). ...

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

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This galaxy goes by the name of ESO 162-17 and is located about 40 million light-years away in the constellation of Carina (The Keel). At first glance this image seems like a fairly standard picture of a galaxy with dark patches of dust and bright patches of young, blue stars. However, a closer look reveals several peculiar features.

Firstly, ESO 162-17 is what is known as a peculiar galaxy — a galaxy that has gone through interactions with its cosmic neighbours, resulting in an unusual amount of dust and gas, an irregular shape, or a strange composition.

Secondly, on 23 February 2010 astronomers observed the supernova known as SN 2010ae nestled within this galaxy. The supernova belongs to a recently discovered class of supernovae called Type Iax supernovae. This class of objects is related to the better known Type-Ia supernovae. ...

[b][i]Credit: ESO, Babak Tafreshi (TWAN)[/i][/b]

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In this romantic scene a bright, crimson sunset complements the colourful centre of the Milky Way and the zodiacal light above the platform of the Very Large Telescope (VLT) on Cerro Paranal.

The pink regions scattered across the disc of our galaxy are regions where new stars are being born. On average the disc is about 1000 light-years tall and about 100 000 light-years in diameter. The setting Sun is just one of over 400 billion stars found in the Milky Way.

Captured in this image is one of the Unit Telescopes (UTs, here UT1 also known as Antu) and three of the four Auxiliary Telescopes (ATs) which form part of the Very Large Telescope Interferometer (VLTI).

To the left of the UT is a very faint meteor, and the red supergiant star Antares stands out above the ATs. Antares is found at the heart of the constellation of Scorpius (The Scorpion).

This photograph was taken by Babak Tafreshi, one of the ESO Photo Ambassadors.

bystander wrote:Young and Dynamic (NGC 2865)
ESA Hubble Picture of the Week | 2015 Apr 13

[b][i]Credit: ESA/Hubble, NASA; Acknowledgment: [/i][/b][url=https://www.flickr.com/photos/geckzilla/9823338186/][b][i]Judy Schmidt[/i][/b][/url]

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This NASA/ESA Hubble Space Telescope image shows an elliptical galaxy called NGC 2865. It lies just over 100 million light-years away from us in the constellation of Hydra — The Sea Serpent — and was discovered in 1835 by astronomer John Herschel.

Elliptical galaxies are usually filled with old, dying stars. NGC 2865, however, is relatively youthful and dynamic, with a rapidly rotating disc full of young stars and metal-rich gas. For an elliptical galaxy it contains an unusually high number of young stars — suggesting that a galaxy-wide starburst took place about one billion years ago.

The starburst itself was induced by a merger between a spiral galaxy, similar to our galaxy, the Milky Way, and an elliptical galaxy some three times more massive — the progenitor galaxy of NGC 2865. The new gas from the spiral galaxy revitalised the dying population of old stars in the elliptical galaxy, and several new generations of stars were born.

The faint halo surrounding the galaxy, visible in this image, is also a result of this merger. It consists of cold gas that was ripped away from the spiral galaxy during the merging process. The gas now forms an almost closed shell around its host galaxy. ...

[b][i]Credit: ESA/Hubble, NASA; Acknowledgment: [/i][/b][url=https://www.flickr.com/photos/geckzilla/9823338186/][b][i]Judy Schmidt[/i][/b][/url]

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This NASA/ESA Hubble Space Telescope image shows an elliptical galaxy called NGC 2865. It lies just over 100 million light-years away from us in the constellation of Hydra — The Sea Serpent — and was discovered in 1835 by astronomer John Herschel.

Elliptical galaxies are usually filled with old, dying stars. NGC 2865, however, is relatively youthful and dynamic, with a rapidly rotating disc full of young stars and metal-rich gas. For an elliptical galaxy it contains an unusually high number of young stars — suggesting that a galaxy-wide starburst took place about one billion years ago.

The starburst itself was induced by a merger between a spiral galaxy, similar to our galaxy, the Milky Way, and an elliptical galaxy some three times more massive — the progenitor galaxy of NGC 2865. The new gas from the spiral galaxy revitalised the dying population of old stars in the elliptical galaxy, and several new generations of stars were born.

The faint halo surrounding the galaxy, visible in this image, is also a result of this merger. It consists of cold gas that was ripped away from the spiral galaxy during the merging process. The gas now forms an almost closed shell around its host galaxy. ...