Editing Hyades (star cluster) (section)

===Stellar multiplicity===
Another result of mass segregation is the concentration of binary systems in the cluster core.<ref name="Perryman" /><ref name="Bohm-Vitense2007" /> More than half of the known F and G stars are binaries, and these are preferentially located within this central region. As in the immediate Solar neighborhood, [[binary star|binarity]] increases with increasing stellar mass. The fraction of binary systems in the Hyades increases from 26% among K-type stars to 87% among A-type stars.<ref name="Bohm-Vitense2007" /> Hyades binaries tend to have small separations, with most binary pairs in shared orbits whose [[semi-major axis|semimajor axes]] are smaller than 50 [[astronomical unit]]s.<ref name="Patience1998">{{cite journal |bibcode=1998AJ....115.1972P |title=The Multiplicity of the Hyades and Its Implications for Binary Star Formation and Evolution |last1=Patience |first1=J. |last2=Ghez |first2=A. M. |last3=Reid |first3=I. N. |last4=Weinberger |first4=A. J. |last5=Matthews |first5=K. |journal=The Astronomical Journal |date=1998 |volume=115 |issue=5 |page=1972 |doi=10.1086/300321 |arxiv=astro-ph/9801216 }}</ref> Although the exact ratio of single to multiple systems in the cluster remains uncertain, this ratio has considerable implications for our understanding of its population. For example, Perryman and colleagues list about 200 high-probability Hyades members.<ref name="Perryman" /> If the binary fraction is 50%, the total cluster population would be at least 300 individual stars.