| Name: Mrinmoy Sarkar |
| Affiliation: Aryabhatta Research Institute of Observational Sciences |
| Conference ID: ASI2026_700 |
| Title: Asteroseismic Modelling of mild Am delta scuti stars : HD 13038 and HD 13079 |
| Abstract Type: Poster |
| Abstract Category: Stars, Interstellar Medium, and Astrochemistry in Milky Way |
| Author(s) and Co-Author(s) with Affiliation: Mrinmoy Sarkar(Aryabhatta Research Institute of Observational Science), Santosh Joshi(Aryabhatta Research Institute of Observational Science), Athul Dileep(Aryabhatta Research Institute of Observational Science), Surath C. Ghosh(Aryabhatta Research Institute of Observational Science), Archana Gupta(Department of Applied Physics, M.J.P. Rohilkhand University, Bareilly, Uttar Pradesh, 263006, India) |
| Abstract: In this work we carry out an asteroseismic study of two mild Am δ Sct pulsators, HD 13038 and HD 13079, using a combination of space-based and ground-based photometry. Multi-sector TESS observations obtained at different cadences were analysed to extract 37 significant pulsation frequencies for HD 13038 and 69 for HD 13079 (SNR > 5). The TESS light curve of HD 13079 is contaminated at the ~15% level by flux from the nearby star HD 13079B, located at an angular separation of 6.48 ± 2.70 arcsec. For HD 13038, we measure a large frequency separation of Δν = 6.08 d⁻¹, and the échelle pattern reveals two near-vertical ridges that are compatible with radial-mode behaviour based on frequency ratios and pulsation constants (Q values). Nevertheless, the asteroseismic age constraints favour the left-ridge solution, identifying radial overtones with orders n = 5 and 7. For HD 13079, the échelle diagram yields Δν = 5.15 d⁻¹ and shows a clear radial ridge corresponding to orders n = 1, 2, 3, 4, and 6. In both stars, the observed excited radial overtones extend to higher order than typically expected for their effective-temperature range. Stellar properties were determined by fitting an extensive mass–metallicity (M–Z) model grid using seismic χ² minimisation, with the identified radial modes applied as key constraints. We also identify possible rotation signals at 0.94 d⁻¹ (HD 13038) and 0.86 d⁻¹ (HD 13079), implying inclination angles of ~90° and ~42°, respectively. These results provides an important step for the study of chemically peculiar Am stars and understanding the process responsible for the excitation of high-radial overtones. |
