The Hercules cluster is certainly an exciting and unusual galaxy cluster! The reason for its varied appearance was stated by today's caption:
APOD Robot wrote:
In fact, the Hercules Cluster itself may be seen as the result of ongoing mergers of smaller galaxy clusters and is thought to be similar to young galaxy clusters in the much more distant, early Universe.
So the Hercules cluster may be very young as galaxy clusters go, and many spiral galaxies remain inside it. Of course, the Hercules cluster is best known for its wonderful interacting galaxies. Most famous of them all is the interacting duo (if not triplet?), known as
NGC 6050. Note the little barred galaxy at top that appears to be caught in the spiral arms of the two larger galaxies! (And there is possibly a
fourth galaxy, yellow and blue-green in color, peeking through a "loop" made of blue spiral arms belonging to one of the two major galaxies!)
Another amazing interacting pair is IC 1178 and IC 1181.
This is the only picture I could find of them. In today's APOD, you find them at about 3 o'clock. These two galaxies are undergoing a so-called "dry merger", which means that they contain no gas, so that their merger produces no star formation. But look at those spectacular tidal tails of old red stars!
There are at least two more amazing galaxies in the Hercules cluster. One is IC 1182.
This picture is strangely pink in color, but it does show the two spectacular blue jets - one long, straight, bright and full of clumps, one fainter and curved - emerging from this otherwise yellow galaxy.
The fourth galaxy I want to call attention to is located close to NGC 6050 and close to a blue star. It is a barred galaxy, surrounded by a blue ring. James D Wray, author of The Color Atlas of Galaxies, wrote about this galaxy that it has an
...extraordinary blue bar. There are practically no galaxies with bars similar to this...
So the Hercules Cluster is a wonderful cluster, with all sorts of galactic activity going on!
Ann
The Hercules cluster is certainly an exciting and unusual galaxy cluster! The reason for its varied appearance was stated by today's caption:
[quote]APOD Robot wrote:
In fact, the Hercules Cluster itself may be seen as the result of ongoing mergers of smaller galaxy clusters and is thought to be similar to young galaxy clusters in the much more distant, early Universe.[/quote]
So the Hercules cluster may be very young as galaxy clusters go, and many spiral galaxies remain inside it. Of course, the Hercules cluster is best known for its wonderful interacting galaxies. Most famous of them all is the interacting duo (if not triplet?), known as [url=http://www.wolaver.org/Space/NGC6050.jpg]NGC 6050[/url]. Note the little barred galaxy at top that appears to be caught in the spiral arms of the two larger galaxies! (And there is possibly a [i]fourth[/i] galaxy, yellow and blue-green in color, peeking through a "loop" made of blue spiral arms belonging to one of the two major galaxies!)
Another amazing interacting pair is IC 1178 and IC 1181. [url=http://upload.wikimedia.org/wikipedia/bs/thumb/e/ec/IC1178-SDSS.gif/250px-IC1178-SDSS.gif]This is the only picture I could find of them.[/url] In today's APOD, you find them at about 3 o'clock. These two galaxies are undergoing a so-called "dry merger", which means that they contain no gas, so that their merger produces no star formation. But look at those spectacular tidal tails of old red stars!
There are at least two more amazing galaxies in the Hercules cluster. One is IC 1182. [url=http://www.observational-cosmology.eu/papaderos/images/ic1182.jpg]This picture is strangely pink in color[/url], but it does show the two spectacular blue jets - one long, straight, bright and full of clumps, one fainter and curved - emerging from this otherwise yellow galaxy.
The fourth galaxy I want to call attention to is located close to NGC 6050 and close to a blue star. It is a barred galaxy, surrounded by a blue ring. James D Wray, author of The Color Atlas of Galaxies, wrote about this galaxy that it has an
[quote]...extraordinary blue bar. There are practically no galaxies with bars similar to this...[/quote]
So the Hercules Cluster is a wonderful cluster, with all sorts of galactic activity going on!
Ann