SIMBAD references

β Cen is a bright β Cephei variable and has long been suspected to be a binary. Here we report interferometric observations with the 3.9-m Anglo-Australian Telescope at a single epoch which show the star to be a binary with components separated by 15 milliarcsec and having approximately equal luminosities at 486 nm. We also present high-resolution spectra taken over five nights with the ESO CAT which show β Cen to be a double-lined spectroscopic binary. We identify two pulsation frequencies in the primary. Further spectroscopic and interferometric studies of this double star should allow determination of its orbital parameters and component masses.