Colliding galaxies

[Run Duke]

Hi, on apod Oct. 27/97 and lot of others we can see two galaxies colliding. My question is: What are the probalities of stars colliding when these events occur considering the angle of collision?

[BMAONE23]

http://antwrp.gsfc.nasa.gov/apod/ap971027.html

Everything I've read about passings and mergers indicates that there is so much space in the space between stars that colliding stars rarely occur during this process.

I would wager that more than one pair of stars collide every time this happens though. With so many billions of stars involved, I don't see how it can't happen.

[starnut]

I'd say the probability of stars colliding during a collision of two galaxies is very low due to the vast distances between stars. For example, the distance between our sun and Alpha Centauri is 4.4 light years, or about 26,000,000,000,000 miles. Compared that with the sun's diameter of 880,000 miles and a Cen's diameter of about 1,000,000 miles. So, plenty of room for another star to pass between them. On the other hand, such close passage could disrupt the orbits of comets lurking in the Oort Cloud or Kuiper Belt, sending them raining into the inner solar system. Much closer, the star could pull the planets out of their orbits!

This doesn't mean, however, such collisions would never happen, especially in the more dense regions like the galactic hub and clusters.

[Qev]

Stellar collisions during galactic mergers would be exceedingly rare, I agree. It does apparently happen from time to time in regions of extremely high stellar density, however, such as the cores of globular clusters. Try googling for blue stragglers for some interesting evidence of this.

[harry]

Hello All

Some say it is rear that stars collide

in this following link millions of stars are facing death due to the collision of two galaxies. Their Black Holes are colliding.

http://www.csmonitor.com/2002/1120/p01s02-ussc.html

within the above link we have also a black hole on the run ripping apart stars in our milky way.

quote:
"On Monday, astronomer Felix Marabel announced he had detected a small black hole speeding through the plane of the Milky Way. The observation - based on the motions of a small star orbiting the black hole - suggests that the black hole is ripping through interstellar space four times as fast as the surrounding stars The black hole - from 3.5 to 15 times as massive as the sun - is thought to have gotten its kick from a supernova explosion."

When galaxies collide star do collide and also affected by the gravity change which causes them to collide with their own member stars. This causes death to many stars and kicks of new star fromations.
http://antwrp.gsfc.nasa.gov/apod/ap031211.html


some nice links on galaxies colliding
http://antwrp.gsfc.nasa.gov/apod/ap030505.html
http://antwrp.gsfc.nasa.gov/apod/ap031010.html
http://antwrp.gsfc.nasa.gov/apod/ap040612.html

http://antwrp.gsfc.nasa.gov/apod/ap040515.html

http://antwrp.gsfc.nasa.gov/apod/ap041121.html

http://antwrp.gsfc.nasa.gov/apod/ap050301.html
http://antwrp.gsfc.nasa.gov/apod/ap051122.html

http://antwrp.gsfc.nasa.gov/apod/ap960822.html


If the universe was expanding why do we have so many galaxies colliding and so many clusters of galaxies.

[Run Duke]

Hi, on apod Oct. 27/97 and lot of others we can see two galaxies colliding. My question is: What are the probalities of stars colliding when these events occur considering the angle of collision?

Thanks...but what about the way they collide...I mean: what if the collision happens for each galaxy to merge from plane to plane instead of doing it face to face?

[harry]

Hello All

The probabilty maybe 1 in a million as a guestimate.

[l3p3r]

that sounds reasonable. certainly not high =)

[harry]

Hello All

Has anybody got images of stars colliding

I have looked through many images and have not found anty stars that are actually colliding.

[Qev]

I don't think anyone has ever directly observed two stars colliding yet, Harry. The event is so rare that, unless we're terribly lucky, we probably never will 'catch them in the act'. We've seen the evidence they leave behind, however, such as the blue stragglers I mentioned earlier.

[harry]

Hello Qev

We can see many images of the resultant collisions.

but! here one near collision.


http://www.space.com/scienceastronomy/n ... 31203.html

I will keep my eye on this one,,,,,,,,,,even in spirit,,,,,,,,,for as long as it takes.


The thing is we see many galaxies colliding.