Abstract
A segregation between cluster members and field stars in the region of the double cluster h and x Persei was done, working from proper motions and positions as kinematic random variables. A two stage process is followed overlapping each time two normal bivariate density functions. The model parameters are estimated solving a nine likelihood non linear equations system, and star membership probabilities are then found by a Baye_sian approach (Brieva and Uribe, 1990). Two different studies are made. The first one finds the h and x Persei physical members working with a 2820 star catalogue published by Lavdovskij (Lavdovskij, 1961). Figure 5 shows a good agreement between the members segregated by our method and those stars considered by Lavdovskij as sure oras the most probable members using other memberhip sources (Lavdovskij, 1965; Van Maanen, 1944; Dieckvos, 1956). A second study is made working with a larger 5504 star catalogue published by Muminov (Muminov, 1982, and http:/ /adc.gsfc.nasa.gov/adc/authors). Figure 6 shows a good agreement between the stars that Muminov considers as probable members and the members, that we segregate in the region of the double cluster.
Keywords
References
Here is the revised list of bibliographic citations with appropriate adjustments:
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