Abstract Details

Name: Sagarika Paul
Affiliation: Osmania University
Conference ID: ASI2021_439
Title : Astrometry and Internal Rotation of 47 Tucanae using Gaia DR2
Authors and Co-Authors : Sagarika Paul (Department of Astronomy, Osmania University, Hyderabad-500007, India), K.Sriram(Department of Astronomy, Osmania University, Hyderabad-500007, India)
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : The Gaia DR2 and Early DR3 (EDR3) provide a huge repository of data for the study of globular clusters with their 5-parameter astrometric solution of Right Ascension, Declination, parallax and proper motion components. For the globular cluster (GC) of 47 Tucanae (NGC104), DR2 was limited in the core region due to high density and brightness. EDR3 improves on that but the core data is still incomplete. Using parametric data for 47 Tucanae from the center out to a radius of 42 arc-seconds, outliers have been filtered on the basis of parallax, proper motion and magnitude. This data has then been fitted to find the cluster tidal and core radius and the astrometric study of the cluster has been carried out to calculate the total proper motion, distance and tangential velocity of the cluster. Gaia has made precession astrometry possible and aided the study of the kinematic properties of Milky Way GCs. Using line of sight velocity, the radial and tangential component of proper motion is calculated which shows whether expansion/contraction of the GC is present or not and whether there is internal rotation of the cluster on the plane of the sky.