Galaxies

Can you spot each of Patrick Moore's top galaxies to see in the night sky during autumn?

Patrick Moore’s top 5 autumn galaxies

The Milky Way can be seen from Earth with the naked eye, but only under dark skies away from light pollution. This image was captured by John Colismo from Chile's Atacama Desert. Credit: John Colosimo (colosimophotography.com)/ESO

What is the Milky Way?

$Andromeda Galaxy, Charles Thody, Pembrokeshire, 8 September 2015. Equipment: Modified Canon EOS 40D DSLR camera, Sky-Watcher Equinox-80 ED apo refractor, Sky-Watcher NEQ6 PRO SynScan mount.$

Readers’ images: top galaxy astrophotos

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 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. Links Images of Hubble

Secrets of galactic butterfly revealed

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A guide to galaxies

The picture shows Abell 2218, a rich galaxy cluster composed of thousands of individual galaxies. It sits about 2.1 billion light-years from the Earth (redshift 0.17) in the northern constellation of Draco. When used by astronomers as a powerful gravitational lens to magnify distant galaxies, the cluster allows them to peer far into the Universe. However, it not only magnifies the images of hidden galaxies, but also distorts them into long, thin arcs. Several arcs in the image can be studied in detail thanks to Hubble's sharp vision. Multiple distorted images of the same galaxies can be identified by comparing the shape of the galaxies and their colour. In addition to the giant arcs, many smaller arclets have been identified.

A guide to gravitational lensing

Artist’s impression of COSMOS-AzTEC-1, a monster galaxy that is forming stars 1,000 times quicker than our own Galaxy. Credit: National Astronomical Observatory of Japan

Astronomers view unstable ‘monster’ galaxy

This image from NASA’s Chandra X-ray Observatory shows the location of different elements in the Cassiopeia A supernova remnant including silicon (red), sulfur (yellow), calcium (green) and iron (purple). Each of these elements produces X-rays within narrow energy ranges, allowing maps of their location to be created. The blast wave from the explosion is seen as the blue outer ring. Astronomers study supernova remnants to better understand how stars produce and then disseminate many of the elements on Earth and in the cosmos at large.

Gravitational waves at galaxy edges

A colour image of the cluster showing the three spectra of the gravitationally lensed images. The graphs show peaks at the same wavelength, indicating they all belong to the same source. Credit: BRADAC/HST/W. M. KECK OBSERVATORY

Faintest early-Universe galaxy confirmed

An image of the galaxies captured by the Atacama Atacama Large Millimeter/submillimeter Array in northern Chile. Credit: ALMA (ESO/NAOJ/NRAO); B. Saxton (NRAO/AUI/NSF)

Galaxies set to form enormous cluster

This image shows the Milky Way, with radio telescope images (pink) of the Magellanic Stream and the Leading Arm. Both structures consist of cosmic gas emanating from the Large and Small Magellanic Clouds. Image Credit: D. Nidever et al., NRAO/AUI/NSF and A. Mellinger, Leiden-Argentine-Bonn (LAB) Survey, Parkes Observatory, Westerbork Observatory, Arecibo Observatory, and A. Feild (STScI)

Hubble solves Magellanic mystery

NCG1277 (insert) was found by searching for compact but massive galaxies, and will now be observed with NASA's Hubble Space Telescope. Image Credit: NASA, ESA, M. Beasley (Instituto de Astrofísica de Canarias), and P. Kehusmaa

Hubble to reveal relic galaxy

Hubble’s view of galaxy GN-z11; now the most distant galaxy ever observed. The galaxy is in fact glowing with bright young blue stars, but is red in this image because its light has been stretched due to the expansion of the Universe. This stretching enabled astronomers to accurately determine its distance. Image Credit: NASA, ESA, P. Oesch (Yale University), G. Brammer (STScI), P. van Dokkum (Yale University), and G. Illingworth (University of California, Santa Cruz)

Hubble spots farthest galaxy ever seen

An artists's depiction of an ultramassive black hole.
Credit: NASA

Astronomers discover ultramassive black holes

An image showing the farthest galaxy ever observed using gravitational lensing. Credits: NASA , ESA, and B. Salmon (STScI)

Gravitational lensing reveals early galaxy