|Authors||Catherine Slesnick, Lynne Hillenbrand, Philip Massey|
|Affiliation||Caltech, Caltech, Lowell Observatory|
|Accepted by||Astrophysical Journal|
|Links||NGC 869 (h Persei) / NGC 884 (chi Persei)|
There is evidence of mild mass segregation within the cluster cores. Our data are consistent with the stars having formed at a single epoch; claims to the contrary are very likely due to the inclusion of the substantial population of early-type stars located at similar distances in the Perseus spiral arm, in addition to contamination by G and K giants at various distances. We discuss the uniqueness of the double cluster, citing other examples of such structures in the literature, but concluding that the nearly identical nature of the two cluster cores is unusual. We fail to settle the long-standing controversy regarding whether or not the double cluster is the core of the Per OB1 association, and argue that this may be unanswerable with current techniques. We also emphasize the need for further work on the pre-main sequence population of this nearby and highly interesting region.