Alkalurops

Also known as Mu Boo or 51 Boo, this is a multiple star system consisting of a widely separated pair, the fainter of which is also a long-period binary star system. The wide pair that makes up Mu¹ and Mu² Boo (making the A-B pair) are separated by 108", which is easily separated even in binoculars. Mu¹is magnitude 4.3.

The fainter star, Mu², is a 7.2 magnitude G1 main sequence star, not unlike our sun. The third component (C) is magnitude 7.7 star currently 2.3" from B. To my eye the A and B components appear white in color. The C component has a slight orange tinge.

The view in a 6" telescope at 270x. North is down and East is right.

The orbital period of the B-C system is 260 years. The two stars are currently near their maximum separation. They will begin to close early in the next century, reaching minimum separation in the early 2100's. The diagram below shows the relative positions of the stars from the 1870's to the 2130's.