Expert: Jayendra Upadhye - 4/7/2004

Question
Hi,

can you tell me if there are stars between galaxies,
individual stars floating in those huge spaces...or are all
celestial objects contained within the spirals and clusters?

thanks for your time!

Allen

Answer
Hi Allen,
The answer is yes and no! For it is very difficult to decide where the "between" starts in the first place!
You see normally most galaxies have extended halos that are roughly spherical. 90 % of the globular cluster of stars lie in the central regions of the spiral galaxies (so is the case with our milky way). These clusters routinely follow "strange" orbital paths, bobbing up and down the otherwise planar geometry of the milky way. In that sense, they are out and between galaxies (but closer to the parent) when they are out of the galactic plane. Also sometimes these are found far out in the halo, above and below the plane of rotation spiral galaxies.
Likewise the products of galactic "fly-pasts" and "intersetions" / "collisions" are the stars flung out far into the intergalactic regions, as seen by "stellar bridges" between galaxies. All these stars fit in as "outsiders"! But in the really desolate middle spaces between galaxies there is "nothing". Reason is that since the big bang, there has been enough time for all matter to "belong" to one or the other galaxy by gravitational accretion. We are now in the age where individuals have ceased to be, and the "collectives" are the in thing! Witness the "great attracter" in the virgo supercluster of galaxies! The largescale structure of the universe is now being built. the age of the "galactic" brick, the solitary star,  is over.
Jayen