7794 20260109155457.0 POSTER-2026-0024 Sarkar, Mrinmoy Asteroseismology of the mild Am delta Sct star HD 118660: TESS photometry and modelling 2025 2025-02-15 We present the results of an asteroseismic study of HD 118660 (TIC 171729860), a chemically peculiar (mild Am) star exhibiting delta scuti pulsations. It is based on the analysis of two sectors of time-series photometry from the space mission TESS ( Transiting Exoplanet Survey Satellite ) and seismic modelling. It yielded the detection of 15 and 16 frequencies for TESS sectors 23 and 50, respectively. The identified pulsation modes include four radial ( l = 0) and five dipolar ( l = 1) ones. The radial modes are overtones with order n ranging from 3 and 6. Such high values of n are theoretically not expected for stars with the effective temperature of HD 118660 ( Teff ≈ 7550 K) located near the red edge of the delta scuti instability strip. To estimate the asteroseismic parameters, we have generated a grid of stellar models assuming a solar metallicity ( Z = 0.014) and different values for the convective overshooting parameter (0.1 ≤ αov ≤ 0.3). We conclude that the analysis of the radial modes is insufficient to constrain αov and Z for delta scuti stars. The value for the equatorial velocity of HD 118660 derived from the seismic radius and the rotational frequency is consistent with values found in the literature. NO Joshi, Santosh Dupret, Marc-Antoine Trust, Otto De Cat, Peter Semenko, Eugene Lampens, Patricia Goswami, Aruna Mkrtichian, David Karinkuzhi, Drisya Yakunin, Ilya Gupta, Archana 43rd meeting of the Astronomical Society of India (ASI2025), Rourkela, India peter.decat@ksb-orb.be 1260133 http://publi2-as.oma.be/record/7794/files/Sarkar2025_AsiSonfP_5.pdf 21222 http://publi2-as.oma.be/record/7794/files/Sarkar2025_AsiSonfP_5.jpg?subformat=icon-180 icon-180 23913 http://publi2-as.oma.be/record/7794/files/Sarkar2025_AsiSonfP_5.gif?subformat=icon icon CPOSTER