Colliding Galaxies

Hubble captures two galaxies colliding.  Image: Credit: NASA and ESA Acknowledgment: A. Gal-Yam (Weizmann Institute of Science)

Hubble captures two galaxies colliding. Image: Credit: NASA and ESA Acknowledgment: A. Gal-Yam (Weizmann Institute of Science)

This is an amazing image. Hubblesite has a “zoomable” version of this and I’ve been trying to count the smaller more distant galaxies – I’m at 22 other than the two subjects of the image.

This NASA Hubble Space Telescope photo of NGC 7714 presents an especially striking view of the galaxy’s smoke-ring-like structure. The golden loop is made of sun-like stars that have been pulled deep into space, far from the galaxy’s center. The galaxy is located approximately 100 million light-years from Earth in the direction of the constellation Pisces.
The universe is full of such galaxies that are gravitationally stretched and pulled and otherwise distorted in gravitational tug-o’-wars with bypassing galaxies.

The companion galaxy doing the “taffy pulling” in this case, NGC 7715, lies just out of the field of view in this image. A very faint bridge of stars extends to the unseen companion. The close encounter has compressed interstellar gas to trigger bursts of star formation seen in bright blue arcs extending around NGC 7714’s center.

The gravitational disruption of NGC 7714 began between 100 million and 200 million years ago, at the epoch when dinosaurs ruled the Earth.

The image was taken with the Wide Field Camera 3 and the Advanced Camera for Surveys in October 2011.
The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA’s Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington, D.C.

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A Lenticular Galaxy

The lenticular galaxy NGC  6861 Credit: ESA/Hubble & NASA; acknowledgement: J. Barrington

The lenticular galaxy NGC 6861 Credit: ESA/Hubble & NASA; acknowledgement: J. Barrington

Hubble gives us this spectacular view of NGC 6861. I always thought this was an elliptical galaxy. Not so, it’s a hybrid of sorts between an elliptical and a spiral called a lenticular.

Not viewable here at 45 deg North, it is a southern object.  Too bad, it’s a beauty.  I believe this galaxy is in the order of 31 Mpc distant or a little over 101 million light-years and still it is a magnitude 11 to 12.  Distances are very tough to determine so there is some room for error.

Note: My computer is failing. Should I disappear for a short time you will know why. I think I can keep it going long enough to get a replacement – still one never knows.

From ESA via the NASA site:

The subject of this image is NGC 6861, a galaxy discovered in 1826 by the Scottish astronomer James Dunlop. Almost two centuries later we now know that NGC 6861 is the second brightest member of a group of at least a dozen galaxies called the Telescopium Group — otherwise known as the NGC 6868 Group — in the small constellation of Telescopium (The Telescope).

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DDO 68 An Odd Little Galaxy

A dwarf galaxy DDO68 might not be as young as it seems.  Copyright: NASA, ESA. Acknowledgement: A. Aloisi (Space Telescope Science Institute)

A dwarf galaxy DDO68 might not be as young as it seems. Copyright: NASA, ESA. Acknowledgement: A. Aloisi (Space Telescope Science Institute)

From the ESA’s Hubble page:

Astronomers have studied galactic evolution for decades, gradually improving our knowledge of how galaxies have changed over cosmic history. The NASA/ESA Hubble Space Telescope has played a big part in this, allowing astronomers to see further into the distance, and hence further back in time, than any telescope before it – capturing light that has taken billions of years to reach us.

Looking further into the very distant past to observe younger and younger galaxies is very valuable, but it is not without its problems for astronomers. All newly-born galaxies lie very far away from us and appear very small and faint in the images. On the contrary, all the galaxies near to us appear to be old ones.

DDO 68, captured here by the NASA/ESA Hubble Space Telescope, was one of the best candidates so far discovered for a newly-formed galaxy in our cosmic neighbourhood. The galaxy lies around 39 million light-years away from us; although this distance may seem huge, it is in fact roughly 50 times closer than the usual distances to such galaxies, which are on the order of several billions of light years.

Read the rest at ESA’s Hubble page.

A side note: I thought this dwarf galaxy was actually two galaxies in the process of merging, apparently not?

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The Serpent’s Nursery

A star forming cloud in the constellation Serpens.  Image credit: NASA/JPL-Caltech/2MASS

A star forming cloud in the constellation Serpens. Image credit: NASA/JPL-Caltech/2MASS

Serpens is one of the constellations we don’t hear much about but is probably familiar if you done much sky watching.

The alpha star has the interesting name of Unukalhai and is located at RA: 15h 45m 00.274s Dec: +06°22’54.854″ or Alt: +50°46’49.676″ Azim: 158°02’58.733″ if you have a compass. I put small finders chart here with the constellation outlined in blue. The tail points almost due south (time is about midnight local).

NASA’s caption:

Within the swaddling dust of the Serpens Cloud Core, astronomers are studying one of the youngest collections of stars ever seen in our galaxy. This infrared image combines data from NASA’s Spitzer Space Telescope with shorter-wavelength observations from the Two Micron All Sky Survey (2MASS), letting us peer into the clouds of dust wrapped around this stellar nursery.
At a distance of around 750 light-years, these young stars reside within the confines of the constellation Serpens, or the “Serpent.” This collection contains stars of only relatively low to moderate mass, lacking any of the massive and incredibly bright stars found in larger star-forming regions like the Orion nebula. Our sun is a star of moderate mass. Whether it formed in a low-mass stellar region like Serpens, or a high-mass stellar region like Orion, is an ongoing mystery.
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A Graceful Arc

A gravitaional lensed galaxy from Hubble and Hershel. Credit: NASA/STScI; S. Allam and team; and the Master Lens Database, L. A. Moustakas, K. Stewart, et al (2014)

A gravitaional lensed galaxy from Hubble and Hershel. Credit: NASA/STScI; S. Allam and team; and the Master Lens Database, L. A. Moustakas, K. Stewart, et al (2014)

Hubble and Herschel combine to study the galaxy known as S0901 seen here as a arc. The arc is a result of huge gravitational forces from a galaxy or galaxies between us and the galactic arc, gravity so strong light from the more distant S0901 is actually magnified and bent into an arc.

Fascinating stuff! I do wonder if we will ever be able to sort of reverse engineer the arc into some semblance of the actual hidden galaxy.

target=”blank’>More images and the following caption at NASA:

The young galaxy SDSS090122.37+181432.3, also known as S0901, is seen here as the bright arc to the left of the central bright galaxy. The distorted view of S0901 is caused by gravitational lensing, resulting from one or more galaxies that lie between the observer and S0901. Although one effect of lensing is to distort the image, another effect is to magnify the light of the lensed object. This effect was used to enable scientists to study S0901 with Herschel’s Heterodyne Instrument for the Far-Infrared (HIFI).

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Centaurus A – A New Look

A new look at Centaurus A.Image credit: X-ray: NASA/CXC/U. Birmingham/M. Burke et al.

Centaurus A is always a treat to see in a good image. This Chandra image gives us an especially good look at those huge jets of material being rejected by the supermassive blackhole at the center of the galaxy.

This image shows those bubble structures too.

From NASA:

Just weeks after NASA’s Chandra X-ray Observatory began operations in 1999, the telescope pointed at Centaurus A (Cen A, for short). This galaxy, at a distance of about 12 million light years from Earth, contains a gargantuan jet blasting away from a central supermassive black hole.
Since then, Chandra has returned its attention to this galaxy, each time gathering more data. And, like an old family photo that has been digitally restored, new processing techniques are providing astronomers with a new look at this old galactic friend.

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Hubble and NGC 660

A rare Polar Ring Galaxy called NGC 660 from Hubble. Credits: ESA/Hubble & NASA

A rare Polar Ring Galaxy called NGC 660 from Hubble. Credits: ESA/Hubble & NASA

Here’s a recent offering from Hubble showing NGC 660, which is described in the caption below from the ESA Week in Pictures.

NGC 660 is a polar ring galaxy, sadly the orientation doesn’t allow us to see that too well. APOD showed the excellent example years ago of NGC 4650A.

This new Hubble image shows a peculiar galaxy known as NGC 660, located around 45 million light-years away from us.

NGC 660 is classified as a “polar ring galaxy,” meaning that it has a belt of gas and stars around its center that it ripped from a near neighbor during a clash about one billion years ago.The first polar ring galaxy was observed in 1978 and only around a dozen more have been discovered since then, making them something of a cosmic rarity.

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