HR 3220

HR 3220 (B Car) is a single-lined spectroscopic binary in the constellation Carina, approximately 65 light years from Earth. The primary is a F-type main sequence star with an apparent magnitude of +4.75. The secondary is most likely a helium white dwarf with 0.47 times the mass of the Sun. Mass transfer from the white dwarf progenitor has given the primary the spectral signature of a blue straggler that appears much younger than its actual age of about 10 billion years.