Abstract Details

Name: Swastik Chowbay
Affiliation: Indian Institute of Astrophysics
Conference ID: ASI2021_76
Title : Host-star Metallicity of Directly Imaged Planets
Authors and Co-Authors : C.Swastik (Indian Institute of Astrophysics), Ravinder K. Banyal (Indian Institute of Astrophysics), Mayank Narang (Tata Institute of Fundamental Research), P. Manoj (Tata Institute of Fundamental Research), T. Sivarani (Indian Institute of Astrophysics), Bacham E. Reddy (Indian Institute of Astrophysics), S. P. Rajaguru (Indian Institute of Astrophysics).
Abstract Type : Oral
Abstract Category : Stars, ISM and Galaxy
Abstract : Planets discovered in wider orbits (≥10 AU) by high-contrast imaging belong to a different region of star-planet parameter space. The star-planet properties and their interdependence is well known for a large number of planetary systems discovered by radial velocity and transit methods. However, host-star properties of the directly imaged planets (DIP) are not very well documented in exoplanet literature. In this work, we used high-resolution spectra from public archives to uniformly determine the atmospheric parameters and metallicity of 18 DIP hosts. The total 22 DIP hosts (other 4 taken from literature) analyzed in this work show a large scatter in metallicity with the median being closer to the Sun. Upon dividing our stellar sample into three mass bins, we noticed a decreasing metallicity trend with increasing mass from Jupiter type planets (MP≤5MJ) to super-Jupiter (5MJ≤MP≤13MJ) and beyond > 13MJ. Using Gaussian-mixture model (GMM), we also show that the metallicity trend in DIP host stars is consistent with the large population of the giant planet and brown-dwarfs found around main-sequence stars.