Nu2 Boötis
Nu2 Boötis is a white-hued binary star system in the northern constellation of Boötes. Its name is a Bayer designation that is Latinized from ν2 Boötis, and abbreviated Nu2 Boo or ν2 Boo. This system is faintly visible to the naked eye as a point of light with a combined apparent visual magnitude of 5.02. Based upon an annual parallax shift of as seen from the Earth, it is located approximately light years from the Sun. The system is moving closer to the Sun with a radial velocity of −16.6 km/s.
This stellar pair have a nearly circular orbit with a period of nine years and a semimajor axis of 0.0615 arc seconds. They are both of visual magnitude 5.80 and display a similar spectrum, with the primary, component A, being an A-type main sequence star with a stellar classification of A5 V. This has been identified as an A-type shell star, suggesting there is a circumstellar disk of gas orbiting one or both stars. There are two other stars that appear close to the pair, termed C and D, but they are physically unrelated.
Ptolemy considered Nu Boötis to be shared by Hercules, and Bayer assigned it a designation in both constellations: Nu Boötis and Psi Herculis. When the modern constellation boundaries were fixed in 1930, the latter designation dropped from use.