Abstract
High-precision proper motions and radial velocities of 1046 stars are used to determine member stars using three-dimensional (3D) kinematics for open cluster NGC 188 based on the density-based spatial clustering of applications with noise (DBSCAN) clustering algorithm. By implementing this algorithm, 472 member stars in the cluster are obtained with 3D kinematics. The color-magnitude diagram (CMD) of the 472 member stars using 3D kinematics shows a well-defined main sequence and a red giant branch, which indicate that the DBSCAN clustering algorithm is very effective for membership determination. The DBSCAN clustering algorithm can effectively select probable member stars in 3D kinematic space without any assumption about the distribution of the cluster or field stars. Analysis results show that the CMD of member stars is significantly clearer than the one based on 2D kinematics, which allows us to better constrain the cluster members and estimate their physical parameters. Using the 472 member stars, the average absolute proper motion and radial velocity are determined to be (PMα, PMδ) = (−2.58 ± 0.22, +0.17 ± 0.18) mas yr−1 and Vr = −42.35 ± 0.05 km s−1, respectively. Our values are in good agreement with values derived by other authors.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.