The nearby star 70 Ophiuchi is one of the best-known and widely studied binary star systems. It's found in an odd V-shaped collection of five stars called Poniatowski's Bull. This strange little asterism is easy to see with the naked eye from suburban skies; if you're in the city, try your finderscope or binoculars. 70 Oph is on the east side of the V; it's near the celestial equator, so it's visible from the northern and southern hemispheres.