λ Bootis-Like Abundances in the Vega-Like, γ Doradus Type-Pulsator HD 218396

This is the authors' abstract. We don't add key points for this paper.

The elemental abundances of 16 elements in the Vega-like and γ Doradus-type variable star HD 218396 have been determined. A model atmosphere with Teff = 7250 \,K, log g = 4.30, and a metallicity of [M/H] =-0.50 was used. A moderate, but definite, deficiency in the abundance of iron, [Fe/H] =-0.55 ± 0.1, has been confirmed. Other elements, Na through Ba, are also as under-abundant as Fe. On the other hand, two light elements, C and O, show solar abundances. These findings confirm the λ Bootis nature of this star, which had been so classified based on a low-resolution optical spectrum. The observed abundance pattern provides a constraint in understanding the nature of this interesting object, which shows excess emission in the infrared region, implying that the star is accompanied by a dusty-debris disk, and at the same time shows photometric and spectroscopic variations arising from non-radial high-order g-mode pulsations.