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View Full Version : Close encounter between Procyon and Luyten's Star



dtilque
2015-Aug-05, 02:20 AM
These two stars are currently just over a lightyear apart. Luyten's Star is further away and has a positive radial velocity, while Procyon has a negative one. So in relatively recent times they've almost certainly been even closer to each other. Has anyone modeled this encounter to determine how close they came and how long ago that was?

Jens
2015-Aug-05, 02:28 AM
These two stars are currently just over a lightyear apart. Luyten's Star is further away and has a positive radial velocity, while Procyon has a negative one. So in relatively recent times they've almost certainly been even closer to each other. Has anyone modeled this encounter to determine how close they came and how long ago that was?

Well, according to Wikipedia:


The closest encounter between the two stars occurred about 600 years ago when Luyten's Star was at its minimal distance of about 1.12 ly from Procyon.

BigDon
2015-Aug-05, 03:55 PM
Is that close enough to have altered their orbits?

Jens
2015-Aug-05, 11:26 PM
I haven't done the math but I can't imagine it would significantly. A light year is such a vast distance.

dtilque
2015-Aug-06, 08:52 AM
One light year (approximate) approaches by stars seem to be fairly routine, which is to be expected considering the average distance between stars and their nearest neighbor is around 5 ly in this region. There was one only 70,000 years ago between Sol and Scholz's Star, for example. At a guess stars average them about once every million years, possibly more often. No doubt someone's done the math on this, but I'm not sure how to search to find it.