The Iota Ursae Majoris system is composed of two sets of
binary stars. The two binary systems orbit around each other once every 2,084 years. The apparent separation between the two binaries is rapidly decreasing as they follow their orbits. In 1841 when the B component was first discovered, they had a separation of 10.7
arcseconds, or at least 156 AU. By 1971 their separation had decreased to 4.5
arcseconds, or at least 66 AU. This system appears to be dynamically unstable with a high likelihood and may become disrupted on a time scale
on the order of 105 years. The brightest component is a white
A-type subgiant. It is a member of a
spectroscopic binary system whose components have an orbital period of 4,028 days. The companion, which has not been directly observed, is thought to be a
white dwarf with a mass of . The companion binary is composed of the 9th magnitude and 10th magnitude stars, both of which are
red dwarfs. These two red dwarfs, designated Iota Ursae Majoris B and C respectively, orbit around each other with a period of 39.7 years, and are separated by roughly 0.7
arcseconds, or at least 10
AU. This pair may be the source of the X-ray emission detected from this system. ==See also==