Pi Boötis

Pi Boötis, Latinized from π Boötis, is a probable triple star system in the northern constellation of Boötes. It is visible to the naked eye with a combined apparent visual magnitude of 4.50. Based upon an annual parallax shift of 10.67 mas as seen from Earth, it is located roughly 310 light years from the Sun.

The brighter primary, component π1 Boötis, has a visual magnitude of 4.89 and a stellar classification of B9 IIIp (MnHgSi), which suggests it is an evolved blue-white hued B-type giant star. It is a chemically peculiar star of the HgMn type, with a spectrum that displays anomalous overabundances of mercury, manganese, and silicon. This component is most likely a single-lined spectroscopic binary with an unknown companion. Its magnitude 5.76 visible companion, π2 Boötis, is a white-hued A-type main-sequence star with a class of A6 V. As of 2010, the pair were separated by $−1.1$ arcseconds on the sky along a position angle of $3.49$. This corresponds to a projected separation of $3.2$. The odds that is a mere chance alignment is 0.85%.

Pi Boötis has the Chinese traditional star name 左攝提二 (Zuǒ shè tí èr)