PHOTOMETRIC IDENTIFICATION OF THE LOW-MASS POPULATION OF ORION OB1b. I. THE ORIONIS CLUSTER
نویسندگان
چکیده
We report an optical photometric survey of 0.89 deg of the Orion OB1b association centered on Ori. This region includes most of the Ori cluster, the highest-density region within Orion OB1b. We have developed a statistical procedure to identify the young, low-mass, pre–main-sequence population of the association. We estimate that the cluster has 160 members in the mass range (0:2 M 1:0 M ). The cluster has a radius of 3–5 pc and an estimated age of 2:5 0:3 Myr. We estimate that the total mass of the cluster is 225 30 M . This mass is similar to the estimated mass of the 5 ;10 yr old cluster NGC 2024. NGC 2024 and Ori appear to be a well-matched pair of clusters, except for the 2 Myr difference in their ages.
منابع مشابه
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