Well known, as in more recently measured.

Saul Levy


On Mon, 05 Feb 2007 08:12:11 GMT, (Paul Schlyter)
wrote:

I would say 200+ years. The first astronomer to detect motion in
binary stars was the good ol' William Herschel....


In article ,
Saul Levy wrote:
Those are binary (double) stars and the movement in their orbits have
been well known for at least 150 years.

Saul Levy