The Black Eye (APOD 02 August 2007)

[Sudhamshu]

It was interesting to note that in M64's Black eye there were 2 concentric counter-rotating system of stars. One in the inner 3,000 light years and the other extending to 40,000 light years.
I wonder what happens at 3,000 light years or the horizon where the rotations of both system of stars intersect. That region must be having some amazing collision of Stars . Eventually, the Black eye might move in the direction of the fastest of the 2 systems.

[astro_uk]

Counter rotation is actually quite common in early type galaxies, the SAURON http://www.strw.leidenuniv.nl/sauron/ team has found many such cases, though the counter rotation is usually confined to the very inner region. My understanding is that the system remains fairly stable, there would be little interaction between the two discs and the situation remains the same for a long period. The SAURON group has found cases of counter rotating cores that could be many Gyr old.

[jimmysnyder]

I wonder what happens at 3,000 light years or the horizon where the rotations of both system of stars intersect. That region must be having some amazing collision of Stars.

The distance between stars, when compared to the diameter of the stars is quite large. Indeed astronomical. Therefor, collisions between stars are extremely rare even during the time that galaxies are colliding. However, the gas and dust between the stars pervades all of the space between them so that when two galaxies collide, that matter, although thin, reacts violently. There might be such action occurring on the boundary between the regions, but my guess is that it has quieted down since the collision,

[ChrisO]

Hi, Thanks for nice SAURON link, that is most fascinating. It seems unimaginable about the amount of data the astronomers can get at with this project.

[bad joke-of-the-day]
So... who gives SAURON the Black Eye? Why Dr. Frodo Baggins of course!
[/bad joke-of-the-day]

[BMAONE23]

Here is another nice image of the central region.

http://heritage.stsci.edu/2004/04/big.html

There is a fair ammount of new star formation at the edge of the dust disk.

(From the Hubble Heritage Archive)
http://heritage.stsci.edu/gallery/gallery.html

[Axel]

I understand encounters between galaxies - even head-on collisions - involve such tenuous structures that anyone living on a planet in one of the galaxies wouldn't notice anything special was happening. But there is contact between dust and molecular clouds, fields, and so forth. So on reading about these counter-rotating disks I wondered if such a galaxy builds up a tremendous charge, like an amber (elektron) rod being rubbed with cat's fur.

[Galvatron]

Hi.
I'm new here but I was just noticing that the center dust cloud structure of the black eye galaxy looks like it's a five sided Pentagon shape. Similar in structure to the phenomenon found recently on Saturn although I think that was six sided.
Seems like these types of structures may be more common throughout the universe and rather contrary to what most would think.

Very interesting.

[iamlucky13]

I understand encounters between galaxies - even head-on collisions - involve such tenuous structures that anyone living on a planet in one of the galaxies wouldn't notice anything special was happening. But there is contact between dust and molecular clouds, fields, and so forth. So on reading about these counter-rotating disks I wondered if such a galaxy builds up a tremendous charge, like an amber (elektron) rod being rubbed with cat's fur.

The thing is that the electromagnetic force is many orders of magnitude more powerful than gravity. As charged particles are exchanged between gas and dust clouds by momentum interactions, the electromagnetic interaction increases, evening out the charge. So on stellar scales the universe tends to remain electrically neutral. This is just one of the many problems with the electric universe theory.

However, vigorous star formation is often a feature of highly disturbed areas like this.

[Sudhamshu]

The distance between stars, when compared to the diameter of the stars is quite large. Indeed astronomical. Therefor, collisions between stars are extremely rare even during the time that galaxies are colliding.

Thanks for correcting me. I searched a little on the web to find out that Star collisions are actually very rare. I find that a bit surprising knowing Gravity is always attractive. My comment was influenced by the bright objects visible close to the centre of the eye.

[jimmysnyder]

I understand encounters between galaxies - even head-on collisions - involve such tenuous structures that anyone living on a planet in one of the galaxies wouldn't notice anything special was happening.

I don't know. I just found out that our galaxy is colliding with the Sagittarius dwarf galaxy. I wasn't all that suprised. I thought I had noticed something special was happening.