I'm presently "working" on clarifying the following sentences in the Runaway star article:
One example of a related set of runaway stars is the case of AE Aurigae, 53 Arietis and Mu Columbae, all of which are moving away from each other at velocities of over 100km/s (for comparison, the Sun moves through the galaxy at about 20km/s faster than the local average). Tracing their motions back, their paths intersect near to the Orion Nebula about 2 million years ago.
My contention is that the "comparison" is meaningless, because the figures being compared are not parallel. While waiting for any response to the question / comment I posed on the discussion page, I did some further research, but don't yet understand what I found well enough to be comfortable editing the article myself. So, until I can get further clarification, I'll collect my research here!
I don't believe that EITHER the Revision as of 13:17, 8 May 2006:
(for comparison, the Sun moves through the galaxy at about 20km/s).
OR the Revision as of 07:47, 6 September 2006:
(for comparison, the Sun moves through the galaxy at about 20km/s faster than the local average).
is accurate!!
The following articles shed some light on the situation:
Mu Columbae
Based on measurements of proper motion and radial velocity, astronomers know that this star and AE Aurigae are moving away from each other at a relative velocity of over 200 km/s. Their common point of origin intersects with Iota Orionis in the Trapezium cluster, some two and half million years in the past. The most likely scenario that could have created these runaway stars is a collision between two binary star systems, with the stars being ejected along different trajectories radial to the point of intersection.
Relative velocity
relative velocity is the change in distance between the two objects with respect to time.
Sun
Velocity: 217 km/s orbit around the center of the Galaxy
20 km/s relative to average velocity of other stars in stellar neighborhood
The Sun orbits the center of the Milky Way galaxy at a distance of approximately 25,000 to 28,000 light-years from the galactic center, completing one revolution in about 225–250 million years. The orbital speed is 217 km/s, equivalent to one light-year every 1,400 years, and one AU every 8 days.[3]
However, before being able to proceed, I need to understand the meaning of this fact from the Orbital characteristics box on the Sun page:
Velocity: 20 km/s relative to average velocity of other stars in stellar neighborhood
(It appears to me that 70.51.9.194 and 71.143.15.148 each had different understandings of this fact, as well.)
I've asked for clarification on the Sun discussion page, but until I get any response there, if anyone reading this can help me out, I would be MOST grateful!
Stay tuned! As I'm a real newbie here, if anyone can help me figure this out, I would be honored! Thanks. 