Amplitude Modulation in a δ Sct star HD 118660
Mrinmoy Sarkar,
Aryabhatta Research Institute of Observational Sciences (ARIES), India and M.J.P Rohilkhand University, Bareilly, Uttar Pradesh-243006, India. Corresponding author: mrinmoysarkar@aries.res.in
Santosh Joshi,
Aryabhatta Research Institute of Observational Sciences (ARIES), India
Peter De Cat,
Royal Observatory of Belgium, Belgium
Abstract
In this paper, we report the detection of amplitude modulation in a δ Scuti star HD 118660. We found that the p-mode frequency at 24.3837 d−1 varies periodically in amplitude with frequency 0.0558±0.00147 d−1. However, all other modes are stable in both amplitude and phase which is clear evidence of non-conservation of visible pulsation mode energy. We constructed a two-frequency model by superimposing two sinusoïds with frequencies ν1 = 24.3837 d−1 and ν2 = 24.4420 d−1 and corresponding phases ϕ1 = 0.5211 rad and ϕ2 = 0.9481 rad to mimic the observed variations of amplitude and phase with time. The plausible explanation of the amplitude modulation in HD 118660 is due to beating of two unresolved closed frequencies ν1 and ν2.
Keywords : Stars: individual : HD 118660-stars, amplitude modulation, TESS : δ Sct : pulsator, chemically peculiar, oscillation-stars
Pour citer cet article
Mrinmoy Sarkar, Santosh Joshi & Peter De Cat, «Amplitude Modulation in a δ Sct star HD 118660», Bulletin de la Société Royale des Sciences de Liège [En ligne], Volume 93 - Année 2024, No 2 - Proceeedings of the 3rd BINA Workshop on the Scientific Potential of the Indo-Belgian Cooperation, 285-293 URL : https://popups.uliege.be/0037-9565/index.php?id=11678.