Have you seen a great image or video somewhere that you think would make a great APOD? Nominate it for APOD! Please post as much information here as you have about the image/video with a link to any source(s) for it you know of here, and the editors will take a look.
When posting the image itself, please do not post anything larger than a thumbnail here; please honor the copyright holder's copyright.
A crazy idea i have has for a long time. To put together a panoramic of the whole Milky Way as seen from our planet Earth. Living in Norfolk UK, this required some travel! The Northern arm of the MW being done at Lands End, Cornwall UK. TheSouthern arm fro mOgato Penninsula New Zealand. 25000 miles travel ! A 70 pane mosaic is the result here.
For better resolution follow link below http://shaunreynoldsastro.com/p23080117 ... #ha73480e4
Re: Found Images: 2018 April
Posted: Sun Apr 01, 2018 10:14 am
by Thierry Legault
I filmed Tiangong-1 this morning over France, passing between Mars and Saturn! Waiting for the crash, next night
This unique image from ESO’s VLT Survey Telescope (VST) reveals two galaxies at the very beginning of the merging process. The interactions between the duo have created a rare effect known as a light echo, where light reverberates around the material within each galaxy. This is analogous to the acoustic echo where the reflected sound arrives at the listener with a delay after the direct sound. This is the first case of a light echo observed between two galaxies.
The larger galaxy, seen here in yellow, is ShaSS 073 — an active galaxy with an extremely luminous core. Its less massive companion, in blue, is named ShaSS 622, and together the pair make up the intriguing ShaSS 622-073 system. The bright core of ShaSS 073 is exciting a region of gas within the disc of its blue companion: it bombards the material there with radiation, causing it to glow brightly as it absorbs and then re-emits this light. This glowing region extends across 1.8 billions of square light-years.
However, while studying this merger, astronomers found the luminosity of the large central galaxy to be 20 times lower than needed to excite the gas in this way. This indicates that the centre of ShaSS 073 has dramatically faded over the last 30 000 years or so — but the highly-ionised region between the two galaxies still retains the memory of its former glory.
An Interacting Galaxy Pair at the Origin of a Light Echo - Paola Merluzzi et al
This image is packed full of galaxies! A keen eye can spot exquisite ellipticals and spectacular spirals, seen at various orientations: edge-on with the plane of the galaxy visible, face-on to show off magnificent spiral arms, and everything in between. The vast majority of these specks are galaxies, but to spot a foreground star from our own galaxy, you can look for a point of light with tell-tale diffraction spikes.
The most alluring subject sits at the centre of the frame. With the charming name of SDSS J0146-0929, the glowing central bulge is a galaxy cluster — a monstrous collection of hundreds of galaxies all shackled together in the unyielding grip of gravity. The mass of this galaxy cluster is large enough to severely distort the spacetime around it, creating the odd, looping curves that almost encircle the cluster.
These graceful arcs are examples of a cosmic phenomenon known as an Einstein ring. The ring is created as the light from a distant objects, like galaxies, pass by an extremely large mass, like this galaxy cluster. In this image, the light from a background galaxy is diverted and distorted around the massive intervening cluster and forced to travel along many different light paths towards Earth, making it seem as though the galaxy is in several places at once.
This unique image from ESO’s VLT Survey Telescope (VST) reveals two galaxies at the very beginning of the merging process. The interactions between the duo have created a rare effect known as a light echo, where light reverberates around the material within each galaxy. This is analogous to the acoustic echo where the reflected sound arrives at the listener with a delay after the direct sound. This is the first case of a light echo observed between two galaxies.
The larger galaxy, seen here in yellow, is ShaSS 073 — an active galaxy with an extremely luminous core. Its less massive companion, in blue, is named ShaSS 622, and together the pair make up the intriguing ShaSS 622-073 system. The bright core of ShaSS 073 is exciting a region of gas within the disc of its blue companion: it bombards the material there with radiation, causing it to glow brightly as it absorbs and then re-emits this light. This glowing region extends across 1.8 billions of square light-years.
However, while studying this merger, astronomers found the luminosity of the large central galaxy to be 20 times lower than needed to excite the gas in this way. This indicates that the centre of ShaSS 073 has dramatically faded over the last 30 000 years or so — but the highly-ionised region between the two galaxies still retains the memory of its former glory.
An Interacting Galaxy Pair at the Origin of a Light Echo - Paola Merluzzi et al
I sure wouldn't know there is a light echo there from looking at the picture.
Ann
Re: ESO: An Echo of Light (ShaSS 622-073)
Posted: Mon Apr 02, 2018 2:53 pm
by Chris Peterson
Ann wrote: ↑Mon Apr 02, 2018 2:27 pm
I sure wouldn't know there is a light echo there from looking at the picture.
No. That information is inferred from spectral and photometric data. As is often the case, the images we are presented with are not the final product, but the initial data that goes into a complex analysis (and this one is certainly complex!)
Adam Block has posted another, brilliant galaxy image. NGC 3561 is the larger, brighter lenticular galaxy, which is interacting with the smaller spiral PGC 33992. The long blue jet at lower left is amazing (how long is it really?), and there is a corresponding, short but bright jet at upper right. Maybe that jet at upper right is really just part of a tidally distorted and starforming arm of PGC 33992.
There is an interesting similarity between this galaxy pair and another pair of interacting galaxies that has been photographed by Adam Block, NGC 317. Like the 3561 pair, NGC 317 consists of a pair of galaxies that are mostly but not entirely yellow, and the interaction has produced a long blue jet here, too.
Light travels to the telescopes at ESO’s La Silla Observatory in Northern Chile over vast distances, from the planets and moons within the Solar System, and from the distant stars of the Milky Way and beyond. This spectacular Ultra High Definition panorama of the observatory, created by ESO Photo AmbassadorBabak A. Tafreshi, captures light from a wide range of celestial objects.
Two of the most prominent sources of light in this spectacular shot are the Large and SmallMagellanic Clouds, which can be seen as two diffuse fuzzy patches at the centre of the photo. These two galaxies are located 160 000 and 200 000 light-years away from us.
The nearest celestial object in this starry scene is Mars, shining next to the open dome of the 1.54-metre Danish telescope in the foreground. At the time of this photograph, the red planet was 93 million kilometres from Earth. Venus, at a distance of 120 million kilometres, can be seen glowing above the MPG/ESO 2.2-metre telescope to the left. The plane of the Milky Way, containing billions of glittering stars, arches above the New Technology Telescope (NTT) and the ESO 3.6-metre telescope, both pictured in the background.
La Silla was ESO’s first observatory and has been an ESO stronghold in the Chilean Atacama Desert since the 1960s. The observatory’s various telescopes help astronomers to explore and understand the many mysteries of the Universe.
This NASA/ESA Hubble Space Telescope image shows a massive galaxy cluster glowing brightly in the darkness. Despite its beauty, this cluster bears the distinctly unpoetic name of PLCK G308.3-20.2.
Galaxy clusters can contain thousands of galaxies all held together by the glue of gravity. At one point in time they were believed to be the largest structures in the Universe — until they were usurped in the 1980s by the discovery of superclusters, which typically contain dozens of galaxy clusters and groups and span hundreds of millions of light-years. However, clusters do have one thing to cling on to; superclusters are not held together by gravity, so galaxy clusters still retain the title of the biggest structures in the Universe bound by gravity.
One of the most interesting features of galaxy clusters is the stuff that permeates the space between the constituent galaxies: the intracluster medium (ICM). High temperatures are created in these spaces by smaller structures forming within the cluster. This results in the ICM being made up of plasma — ordinary matter in a superheated state. Most luminous matter in the cluster resides in the ICM, which is very luminous X-rays. However, the majority of the mass in a galaxy cluster exists in the form of non-luminous dark matter. Unlike plasma, dark matter is not made from ordinary matter such as protons, neutrons and electrons. It is a hypothesised substance thought to make up 80 % of the Universe’s mass, yet it has never been directly observed.
This image was taken by Hubble’s Advanced Camera for Surveys and Wide-Field Camera 3 as part of an observing programme called RELICS (Reionization Lensing Cluster Survey). RELICS imaged 41 massive galaxy clusters with the aim of finding the brightest distant galaxies for the forthcoming NASA/ESA/CSA James Webb Space Telescope (JWST) to study.
