AR Cassiopeiae

AR Cassiopeiae (AR Cas) is a multiple star system in the constellation of Cassiopeia. It is thought to be a septuple star system. It is one of only two known star systems with a multiplicity of 7, the other being Nu Scorpii, with no physical multiple stars of greater multiplicity yet found as of January 2020.
Nomenclature.
AR Cassiopeiae was frequently referred to as IH Cas (or H Cas) in some literature. The origin of the designation "IH Cassiopeiae" is from the 17th century catalogue and constellation map by Johannes Hevelius, which was kept in use due to the lack of a Flamsteed designation or Bayer designation for the star. It was the first star in Cassiopeia that Flamsteed's edition of Hevelius catalogued, thus "1 Hev. Cas" or "1 H. Cas" (similar to Gould designations), which becomes IH Cas through corruption.
Properties.
The primary subsystem, AR Cassiopeiae AB, is a triple. AR Cassiopeiae B is located 0.800″ away from AR Cassiopeiae A. AR Cassiopeiae A itself an Algol-type eclipsing binary with an orbital period of about 6.07 days. Its primary is a B-type main-sequence star, and the secondary, an A-type main-sequence star. The secondary star may be an Am star as well.
Farther out are two other stars, designated AR Cassiopeiae C and D, respectively. They are 76.1″ (or about 1.27′) away from the central system. Their combined spectrum matches that of another B-type main-sequence star. This pair is also designated HD 221237. 67.2″ (1.12′) away from AR Cassiopeiae AB is another pair of stars, F and G, both F-type stars. All four of these stars are known to be common proper motion companions.