70 Ophiuchi is a binary star system located 16.6 light years away from the Earth.

At magnitude 4 it appears as a dim star visible to the unaided eye away from city lights.

This was an important contribution to the proof that Newton's law of universal gravitation applied to objects beyond the Solar System.

[9] In 1855, William Stephen Jacob of the Madras Observatory claimed that the orbit of the binary showed an anomaly, and it was "highly probable" that there was a "planetary body in connection with this system".

[26] A claim of a planetary system was again made, this time by Dirk Reuyl and Erik Holberg in 1943.