Nu2 Sagittarii


Nu2 Sagittarii is a binary star system in the zodiac constellation of Sagittarius. It is faintly visible to the naked eye, having an apparent visual magnitude of +4.98. Based upon a small annual parallax shift of 11.91 mas as seen from Earth, this system is located around 270 light years from the Sun. Nu2 Sagittarii has a high peculiar velocity of and is most likely a runaway star system.
The spectrum of the primary component displays a stellar classification of K1 Ib–II, indicating this is a K-type star with a mixed luminosity class of an evolved bright giant/supergiant star. It is a mild barium star, showing an enhanced abundance of s-process elements in its outer atmosphere. This material was most likely acquired during a previous mass transfer from its now white dwarf companion. The primary has an estimated 1.4 times the mass of the Sun and has expanded to 85 times the Sun's radius.