Name: Athira Unni
Affiliation: Indian Institute of Astrophysics
Conference ID : ASI2022_54
Title : Carbon abundance of stars in the LAMOST-Kepler field
Authors : Athira Unni (Indian Institute of Astrophysics, Bangalore) Mayank Narang (Tata Institute of Fundamental Research), Thirupathi Sivarani (Indian Institute of Astrophysics, Bangalore), Manoj Puravankara (Tata Institute of Fundamental Research), and Ravinder Banyal (Indian Institute of Astrophysics, Bangalore)
Abstract Type: Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : Planet and host stars are formed from the same molecular cloud. Hence, it is expected that the chemical composition of the planet will correlate with that of the host star. Planet - metalicity (Fe/H) correlation is well established for the giant planets with radius Rp>4R⊕. It is also possible that individual elements may contribute to the planet formation more than the overall metallic content of the protoplanetary disk. We present carbon abundance derived from low-resolution LAMOST spectra for the Kepler field stars. Synthetic spectra fitting of CH band was performed for deriving carbon abundances. The abundances patterns are compared with other high-resolution spectroscopic surveys, such as APOGEE, HARPS-GTO, and compiled literature values from the Hypatia catalog , and the abundance trends are consistent with the previous studies. Finally, we compare metallicity and carbon abundance between exoplanet host stars and field stars. Massive Jupiter host stars are found to be metal-rich which is similar to earlier studies. We also find the carbon abundance relative to iron to be poor for massive Jupiters. This is consistent with the chemical evolution of younger stars in the thin disk, which are metal-rich and [C/Fe]<0.0. This indicates massive Jupiters were forming only recently as proposed by Mayank et al. (2021). It is interesting to note that an environment that is metal-rich but carbon poor helps in the formation of massive cores.