2025/08/28 by Ghosh, Surath C., Joshi, Santosh, Ghosh, Samrat +9
#FOS: Physical sciences #Solar and Stellar Astrophysics (astro-ph.SR)
paper · doi:10.48550/arxiv.2508.20681
Using \tess short-cadence (120 s) SAP flux, we identified a rotational frequency of 0.09655 d-1 (Prot=10.35733 d). Wavelet analysis reveals that while the amplitudes of the harmonic components vary over time, the strength of the primary rotational frequency remains stable. A SED analysis of multi-band photometric data yields an effective temperature (Teff) of 11,750 K. %MDPI: Comma added for five digits in the whole text, please check. High-resolution spectroscopic observations covering wavelengthrange 4500--7000 Å provide refined estimates of \teff = 13,814 ± 400 K, \logg = 4.09 ± 0.08 dex, and \vsini = 16 ± 1 \kms. Abundance analysis shows solar-like composition of O ii, Mg ii, S ii, and Ca ii, while helium is under-abundant by 0.62 dex. Rare earth elements (REEs) exhibit over-abundances of up to 5.2 dex, classifying the star as an Ap/Bp-type star. AL Col has a radius of R = 3.74 ± 0.48\rm R\odot, with its H--R diagram position estimating a mass of M = 4.2 ± 0.2\rm M\odot and an age of 0.12 ± 0.01 Gyr, indicating that the star has slightly evolved from the main sequence. The \tess light curves were modeled using a three-evolving-spot configuration, suggesting the presence of differential rotation. This star is a promising candidate for future investigations of magnetic field diagnostics and the vertical stratification of chemical elements in its atmosphere.