Joshi, S. ; Trust, O. ; Williams, E.P. ; Semenko, E. ; De Cat, P. ; Jurua, E. ; Holdsworth, L.D. ; García, R.A. ; Abedigamba, O.P.

Poster presented at Sub-Saharan Africa Astronomy Summer School "Galaxies, Extrasolar Planets, and Stellar Physics: Gazing into the deep space, searching for new worlds, and insights into stellar interior physics", Entebbe, Uganda on 2022-09-19

Abstract: We aim to carry out a study on the photometric and spectroscopic variabilities of four stars monitored in the Nainital-Cape survey. We analysed the photometric variability of the target stars, HD 73135, BD +19° 2045, BD +19° 2046, and TYC 1395-855-1, using ground-based differential photometric and K2 data. Spectrophotometric and high-resolution spectroscopic data are used to determine the fundamental parameters and chemical abundances. Although all the target are found to be non-variable based on ground-based differential photometry, the analysis of high-precision K2 photometric time-series reveals that HD 73135, BD +19° 2045, and BD +19° 2046 are variable. We do not detect photometric variability in TYC 1395-855-1. Our analyses show that the three stars, HD 73135, BD +19° 2045, BD +19° 2046, which are non-variable based on ground- based observations exhibit rotational variability in Kepler K2 data while TYC 1395-855-1 remains constant in both data sets. Based on the chemical abundance analysis, HD 73135 is an Am star, while BD +19° 2045 is non-Am.

Keyword(s): Stars: chemically peculiar ; Stars: rotation ; Stars: starspots ; Stars: general
Note: DOI: 10.5281/zenodo.7118369
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