[yongjik]

I believe they are coming close when viewed from the Earth - that is, the second star (S5) may come directly behind Alpha Centauri. Alpha Centauri is only 1.3 parsecs from us, so it's actually much closer to us than S5.

[tomtom1337]

Thank you! Arcsecond is a 2d measurement! One star is coming within a small distance of the other star when looking at the projected image!