The proper motion of this star has been known for some time but it was thought to be much further away.
The stars share the same proper motion so they are probably related.
I answer you that by the proper motion of the stars alone it would have been difficult.
They had even moved a few of them slightly, a year ago, to correct for proper motion.
This star is also notable for its large proper motion.
Also, eight of the ten stars with the biggest proper motions are less than 15 light years away.
This system is also known for its high proper motion of about 1 arc second a year.
Only seven stars with such large proper motions are currently known.
It has a relatively high proper motion and is located within 27 light years of the Sun.
There were only about 100,000 stars for which proper motion could not be derived.
Wörterbuch für Astronomie