Multiplicity among F-type Stars

As part of a homogeneous all-sky volume-complete sample of half a thousand solar-type stars within 25 pc we present a census for the subset of the 150—mostly F-type stars—in the mass range 1.1 M _⊙ <= M <= 1.7 M _⊙ in terms of their observed multiplicities. The major obstacle, as expected, arises from the onset of stellar rotation in this mass range for it continues to support many hidden companions. Yet, a solid increase of the fraction of binary and higher level systems as a function of the primary mass is manifest. There is even the prospect that on account of many companion candidates the single-star fraction may already converge to zero at the transition to the A-type stars.