Starship Asterisk*

[quote="Arioch"]

Here's a simulation showing how the ring is formed by a sort of inverted "splash",
as the intruder galaxy attracts the stars of the larger galaxy and flings them past each other:

https://www.youtube.com/watch?v=Q6HU-TfAM5g[/quote]
http://www.spacetelescope.org/products/art/akira_inaka_11/

Here's a simulation showing how the ring is formed by a sort of inverted "splash", as the intruder galaxy attracts the stars of the larger galaxy and flings them past each other:

https://www.youtube.com/watch?v=Q6HU-TfAM5g

I love the image from the "small intruder" link. :kitty:

I am though worried about what may form from the yolk in the see through egg of AM 0644-741. :ohno:

perhaps the ring formation is the result of unequal distribution of mass within the galaxy. computer simulation programs probably can be devised to study dynamics in stellar and galactic structure which show wide deviation from the norm. such programs, built upon basic mathematical relationships of matter and force, can be used to approximate myriad types of stellar and galactic structure. the simplest and most informative of these were programs that simulated evolution of the solar system in which placement and mass of the various planetary bodies were inferred.

[quote="Beyond"][quote="Boomer12k"]Would not the Intruder galaxy have dragged a star stream out and behind it?

:---[===] *[/quote]
If you click on the 'small Intruder' link, you'll see that there is plainly a well formed tail following behind it.[/quote]

And "it" knows it's the "star!"

I had to go to "The Lure of the Rings" to find the companion galaxy. My link from "intruder" at APOD took me to a couple of cute puppies being pushed aside by a kitten!

I remember being absolutely wowed by this amazing image when it was first released many years ago! This is probably the most well known southern peculiar galaxy catalogued by Halton Arp and Barry Madore in the AM catalogue.

[quote="Boomer12k"]Would not the Intruder galaxy have dragged a star stream out and behind it?

:---[===] *[/quote]
If you click on the 'small Intruder' link, you'll see that there is plainly a well formed tail following behind it.

Would not the Intruder galaxy have dragged a star stream out and behind it?

:---[===] *

[url=http://apod.nasa.gov/apod/ap150419.html][img]http://apod.nasa.gov/apod/calendar/S_150419.jpg[/img] [size=150]Ring Galaxy AM 0644-741 from Hubble[/size][/url]

[b] Explanation: [/b] How could a galaxy become shaped like a ring? The rim of the blue galaxy [url=http://heritage.stsci.edu/2004/15/caption.html]pictured[/url] on the right is an immense ring-like structure 150,000 [url=http://chandra.harvard.edu/photo/cosmic_distance.html]light years[/url] in diameter composed of newly formed, extremely bright, massive stars. That galaxy, [url=http://adsabs.harvard.edu/abs/1997ApJ...474..686H]AM 0644-741[/url], is known as a [url=http://apod.nasa.gov/apod/ap010612.html]ring galaxy[/url] and was caused by an immense galaxy collision. When [url=http://apod.nasa.gov/apod/ap150201.html]galaxies collide[/url], they pass through each other -- their individual stars rarely come into contact. The [url=http://en.wikipedia.org/wiki/Engagement_ring]ring[/url]-like shape is the result of the [url=http://en.wikipedia.org/wiki/Tidal_force]gravitational disruption[/url] caused by an entire [url=https://s-media-cache-ak0.pinimg.com/736x/5b/60/1e/5b601e8413f01f169a27dffd3a1e1601.jpg]small intruder[/url] galaxy passing through a large one. When this happens, interstellar gas and [url=http://apod.nasa.gov/apod/ap030706.html]dust[/url] become condensed, causing a [url=http://astronomy.swin.edu.au/cosmos/D/density+wave+model]wave of star formation[/url] to move out from the impact point like a ripple across the surface of a pond. The intruder galaxy is just outside of the frame taken by the [url=http://www.stsci.edu/hst/HST_overview/]Hubble Space Telescope[/url]. This [url=http://hubblesite.org/newscenter/archive/releases/2004/15/image/a/]featured image[/url] was taken to [url=http://hubble25th.org/]commemorate the anniversary[/url] of [url=https://www.youtube.com/watch?v=on7_7WZmdgI]Hubble's launch[/url] in 1990. [url=http://apod.nasa.gov/apod/ap020909.html]Ring galaxy[/url] AM 0644-741 lies about 300 million light years away.

[b][table][tr][td=left][url=http://asterisk.apod.com/discuss_apod.php?date=150418]<< Previous APOD[/url][/td] [td=center][url=http://asterisk.apod.com/view_retro.php?date=0419]This Day in APOD[/url][/td] [td=right][url=http://asterisk.apod.com/discuss_apod.php?date=150420]Next APOD >>[/url][/td][/tr][/table][/b]