Expert: Jayendra Upadhye - 5/13/2005

Question
Hi.

I've read that our sun is rotating with our galaxy. However, does this mean our galaxy is revolving round itself (spinning, I guess) or revolving around other galaxies or both?

My second question is very similar. do galaxies orbit other galaxies. I've also read galaxies form galaxy clusters and galaxy clusters form superclusters. Do the galaxy clusters and the superclusters also spin and revolve?

Thanks

Answer
Hi Stefan,
1 - yes our galaxy is revolving about its axis that passes thru its central spherical hub.

2 - If a spiral galaxy has a companion, then depending on their relative velocities, they either orbit one another or collide and form an elliptical galaxy.

3 - In case of super clusters, there is generally a monster galaxy that gobbles up the constituents over time. Also, the overall mass of the cluster has its own identity and pull.
we are headed towards the virgo cluster at about 300 kn.sec, and will arrive there in a few billion years.
Jayen