• How Common can the Origin of Clusters Cha I, Cha II, epsilon Cha and η Cha be?

    分类: 天文学 >> 天文学 提交时间: 2024-05-24 合作期刊: 《Research in Astronomy and Astrophysics》

    摘要: The trajectories of the groupings η Cha, Cha and Cha I, Cha II, constructed backward in time, have been studied. We concluded that the hypothesis about the joint formation of all four of these clusters from one molecular cloud cannot be completely excluded. However, 10–15 Myr ago, all these four clusters were located at approximately the same height above the plane of the Galaxy. Thus, the gas-dust clouds from which all these four clusters were formed were located on one broad front. It is possible that the appearance of the Cha I, Cha II, Cha and η Cha clusters may be associated with the impact on such a front of shock waves formed after supernova explosions in the Scorpius–Centaurus association. New estimates of the kinematic ages of the clusters Cha I and Cha II are obtained as 0.12 ± 0.19 and 0.05 ± 0.15, respectively. It is shown that the minimum size of the Cha I-north and Cha I-south clusters corresponded to the time of 0.55 ± 0.24 Myr and 0.04 ± 0.18 Myr ago, respectively, and approximately 1.5 Myr ago the distance between the trajectories of these two groupings was minimal.

  • The Radcliffe Wave Parameters from Data on Open Star Clusters

    分类: 天文学 >> 天文学 提交时间: 2024-03-29 合作期刊: 《Research in Astronomy and Astrophysics》

    摘要: A spectral analysis of the vertical positions and velocities of 374 open star clusters (OSCs) was carried out. We took these OSCs from the Hunt and Reffert catalog; they have an average age of about 10 million years, and are located on the galactic plane XY in a narrow zone inclined by 25° to the galactic axis Y. The following estimates of the parameters of the Radcliffe wave were obtained: (a) the maximum value in periodic perturbations of vertical coordinates  pc with the wavelength of these perturbations λz = 4.82 ± 0.09 kpc; (b) the maximum value of the velocity of vertical disturbanceskm s−1 with disturbance wavelength λW = 1.78 ± 0.02 kpc. Note that the results of the vertical velocity analysis are first-class in accuracy and completely new.