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Author Pandey, C. P. ♦ Morel, T. ♦ Briquet, M. ♦ Jaykumar, K. ♦ Bisht, S. ♦ Sanwal, B. B.
Source Aryabhatta Research Institute of Observational Sciences (ARIES)
Content type Text
File Format PDF
Language English
Subject Domain (in DDC) Natural sciences & mathematics ♦ Physics
Subject Keyword Individual Objects: γ Pegasi
Abstract The recent detection of both pressure and high-order gravity modes in the classicalB-type pulsator γ Pegasi offers promising prospects for probing its internalstructure through seismic studies. To aid further modelling of this star, wepresent the results of a detailed NLTE abundance analysis based on a largenumber of time-resolved, high-quality spectra. A chemical composition typicalof nearby B-type stars is found. The hybrid nature of this star is consistent withits location in the overlapping region of the instability strips for β Cephei andslowly pulsating B stars computed using OP opacity tables, although OPAL calculationsmay also be compatible with the observations once the uncertaintiesin the stellar parameters and the current limitations of the stability calculationsare taken into account. The two known frequencies f₁ = 6.58974 andf₂ = 0.68241 d¯¹ are detected in the spectroscopic time series. A mode identificationis attempted for the low-frequency signal, which can be associated toa high-order g-mode. Finally, we re-assess the binary status of γ Peg and findno evidence for variations that can be ascribed to orbital motion, contrary toprevious claims in the literature.
Part of series cia162
Educational Use Research
Education Level UG and PG
Learning Resource Type Article