Abstract Details
| Name: PARTHAPRATIM GOSWAMI Affiliation: IIA, Bengaluru Conference ID: ASI2019_94 Title : Chemical analysis of HE 0308-1612 and HE 0017+0055 Authors and Co-Authors : Author: Partha Pratim Goswami, Co-Author: Prof. Aruna Goswami Abstract Type : Poster Abstract Category : Stars, ISM and Galaxy Abstract : Recent results obtained from high resolution spectroscopic analysis of two stars HE 0308-1612, and HE 0017+0055 classified as potential CH star candidates (Goswami 2005, Goswami et a. 2010) are presented here. The classification was based on low resolution spectroscopy, and, follow-up high resolution spectroscopic analysis was essential to confirm their classification. CH stars form important probes as halo tracers. They belong to spectral class giant or sub-giant, but majority of them show surface chemical composition with enhanced abundances of s-process heavy elements. As stars in their giant or subgiant phases are not expected to produce heavy elements, the origin of the enhanced heavy elements observed in these stars are atributed to s-process nucleosynthesis occurring in a binary companion. From a detailed analysis of the elemental abundance estimates and abundance patterns we have confirmed the classification of these objects. While HE 0308-1612 is found to be mildly metal-poor with [Fe/H]=−0.73, and enhanced in carbon with [C/Fe]=0.78, HE 0017+0055 is found to be more metal-poor with [Fe/H]=−2.59. Carbon is also highly enhanced in this object with [C/Fe]=2.71. Further, this object also shows high abundance of r-process element (i.e., Eu) indicating that the origin of the heavy elements may be i-process nucleosynthesis. Such a possibility is discussed at length. A detailed analysis of the observed abundance patterns is also conducted based on several other existing nucleosynthesis theories for a better understanding of the origin and evolution of these stars. |