[xJones]

Now determined to lie only 1,440 light-years away, the Cygnus Loop is thought to have been expanding for 5 - 10 thousand years.

Only 5 - 10 thousand years old? The Cygnus Loop is a baby!

[RightWhale]

Now determined to lie only 1,440 light-years away, the Cygnus Loop is thought to have been expanding for 5 - 10 thousand years.

This would be in the time range to be part of the historical record.