Starship Asterisk*

[b][i]Credit: ESO, B. Yang and Z. Wahhaj[/i][/b]

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These images, taken two weeks apart, show the two hemispheres of Ceres and provide the best ground-based observations of the dwarf planet ever. They were taken using the SPHERE instrument on ESO's Very Large Telescope and form part of an effort undertaken since mid-July 2015 to compose a polarimetric map of the object's surface.

Orbiting in the asteroid belt between Mars and Jupiter, a region known as the Main Belt, Ceres was the first asteroid to be discovered in 1801 and is the largest Main Belt asteroid. It is the largest reservoir of water in Earth's neighbourhood. Most of this water is thought to exist in the form of water ice in the object's mantle.

The surface of the dwarf planet is about the size of India and several intriguing bright spots can be seen in these new images. These mysterious bright patches have also been looked at more closely by NASA's Dawn spacecraft, currently in orbit around Ceres. Astronomers have scrutinised them, but their true nature remains obscure. It is hoped, however, that by comparing the data obtained using SPHERE with the images Dawn is sending to Earth, astronomers should soon be able to begin decoding the Ceres enigma.

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The arrangement of the spiral arms in the galaxy Messier 63, seen here in a new image from the NASA/ESA Hubble Space Telescope, recall the pattern at the centre of a sunflower. So the nickname for this cosmic object — the Sunflower Galaxy — is no coincidence.

Discovered by Pierre Mechain in 1779, the galaxy later made it as the 63rd entry into fellow French astronomer Charles Messier’s famous catalogue, published in 1781. The two astronomers spotted the Sunflower Galaxy’s glow in the small, northern constellation Canes Venatici (the Hunting Dogs). We now know this galaxy is about 27 million light-years away and belongs to the M51 Group — a group of galaxies, named after its brightest member, Messier 51, another spiral-shaped galaxy dubbed the Whirlpool Galaxy.

Galactic arms, sunflowers and whirlpools are only a few examples of nature’s apparent preference for spirals. For galaxies like Messier 63 the winding arms shine bright because of the presence of recently formed, blue–white giant stars, readily seen in this Hubble image.

[img3="Credit: ESA/Hubble & NASA
Acknowledgement: Judy Schmidt (geckzilla.com)"]http://cdn.spacetelescope.org/archives/ ... w1537a.jpg[/img3][hr][/hr]

It is known today that merging galaxies play a large role in the evolution of galaxies and the formation of elliptical galaxies in particular. However there are only a few merging systems close enough to be observed in depth. The pair of interacting galaxies picture seen here — known as NGC 3921 — is one of these systems.

NGC 3921 — found in the constellation of Ursa Major (The Great Bear) — is an interacting pair of disc galaxies in the late stages of its merger. Observations show that both of the galaxies involved were about the same mass and collided about 700 million years ago. You can see clearly in this image the disturbed morphology, tails and loops characteristic of a post-merger.

The clash of galaxies caused a rush of star formation and previous Hubble observations showed over 1000 bright, young star clusters bursting to life at the heart of the galaxy pair.

[img3="Credit: NASA/JPL-Caltech/Space Science Institute"]http://s3.amazonaws.com/ciclops_ir_2015 ... 9478_2.png[/img3][hr][/hr]

The night sides of Saturn and Tethys are dark places indeed.

We know that shadows are darker areas than sunlit areas, and in space, with no air to scatter the light, shadows can appear almost totally black.

Tethys (660 miles or 1,062 kilometers across) is just barely seen in the lower left quadrant of this image below the ring plane and has been brightened by a factor of three to increase its visibility.

The wavy outline of Saturn's polar hexagon is visible at top center.

This view looks toward the sunlit side of the rings from about 10 degrees above the ring plane. The image was taken with the Cassini spacecraft wide-angle camera on Jan. 15, 2015 using a spectral filter which preferentially admits wavelengths of near-infrared light centered at 752 nanometers.

The view was obtained at a distance of approximately 1.5 million miles (2.4 million kilometers) from Saturn. Image scale is 88 miles (141 kilometers) per pixel.

bystander wrote:Evolution in Slow Motion (NGC 3921)
ESA Hubble Picture of the Week | 2015 Sep 14

[img3="Credit: ESA/Hubble & NASA
Acknowledgement: Judy Schmidt (geckzilla.com)"]http://cdn.spacetelescope.org/archives/ ... w1537a.jpg[/img3][hr][/hr]

It is known today that merging galaxies play a large role in the evolution of galaxies and the formation of elliptical galaxies in particular. However there are only a few merging systems close enough to be observed in depth. The pair of interacting galaxies picture seen here — known as NGC 3921 — is one of these systems.

NGC 3921 — found in the constellation of Ursa Major (The Great Bear) — is an interacting pair of disc galaxies in the late stages of its merger. Observations show that both of the galaxies involved were about the same mass and collided about 700 million years ago. You can see clearly in this image the disturbed morphology, tails and loops characteristic of a post-merger.

The clash of galaxies caused a rush of star formation and previous Hubble observations showed over 1000 bright, young star clusters bursting to life at the heart of the galaxy pair.

geckzilla wrote:

bystander wrote:Evolution in Slow Motion (NGC 3921)
ESA Hubble Picture of the Week | 2015 Sep 14

[img3="Credit: ESA/Hubble & NASA
Acknowledgement: Judy Schmidt (geckzilla.com)"]http://cdn.spacetelescope.org/archives/ ... w1537a.jpg[/img3][hr][/hr]

It is known today that merging galaxies play a large role in the evolution of galaxies and the formation of elliptical galaxies in particular. However there are only a few merging systems close enough to be observed in depth. The pair of interacting galaxies picture seen here — known as NGC 3921 — is one of these systems.

NGC 3921 — found in the constellation of Ursa Major (The Great Bear) — is an interacting pair of disc galaxies in the late stages of its merger. Observations show that both of the galaxies involved were about the same mass and collided about 700 million years ago. You can see clearly in this image the disturbed morphology, tails and loops characteristic of a post-merger.

The clash of galaxies caused a rush of star formation and previous Hubble observations showed over 1000 bright, young star clusters bursting to life at the heart of the galaxy pair.

ESA's processor did a great job with this one. Back when I did it I only got partial frames in. Not sure why I missed or didn't include the other half. It's great to see the whole galaxy.
https://www.flickr.com/photos/geckzilla/9616920431/

[c][attachment=0]eso1536a[1].jpg[/attachment][/c]

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The Sculptor Dwarf Galaxy, pictured in this new image from the Wide Field Imager camera, installed on the 2.2-metre MPG/ESO telescope at ESO’s La Silla Observatory, is a close neighbour of our galaxy, the Milky Way. Despite their close proximity, both galaxies have very distinct histories and characters. This galaxy is much smaller and older than the Milky Way, making it a valuable subject for studying both star and galaxy formation in the early Universe. However, due to its faintness, studying this object is no easy task.

The Sculptor Dwarf Galaxy — also known as the Sculptor Dwarf Elliptical or the Sculptor Dwarf Spheroidal — is a dwarf spheroidal galaxy, and is one of the fourteen known satellite galaxies orbiting the Milky Way. These galactic hitchhikers are located close by in the Milky Way’s extensive halo, a spherical region extending far beyond our galaxy’s spiral arms. As indicated by its name, this galaxy is located in the southern constellation of Sculptor and lies about 280 000 light-years away from Earth. Despite its proximity, the galaxy was only discovered in 1937, as its stars are faint and spread thinly across the sky.

Although difficult to pick out, the Sculptor Dwarf Galaxy was among the first faint dwarf galaxies found orbiting the Milky Way. The tiny galaxy’s shape intrigued astronomers at the time of its discovery, but nowadays dwarf spheroidal galaxies play a more important role in allowing astronomers to dig deeply into the Universe’s past. ...