Proper motions and variabilities of stars near the Orion Nebula

摘要: Relative proper motions were measured and membership probabilities determined for over 1000 stars within 15-arcmin of the center Orion Nebula, M42. About 900 are associated with complex. The sufficient precision to measure internal velocity dispersions. These dispersions nearly isotropic, depend only weakly on magnitude distance from Trapezium. corresponding dispersion in one coordinate is just 2 km/s. distribution follows closely gas as by CO-13. appear be, at most, bound molecular cloud. A search variable has found that half member either known variables or showed variation plates. 30 references.