Poster abstract details
Studying the hybrid pulsator 12 Lacertae: extended mode identification and complex seismic modelling
Abstract
12 Lacertae is one of the most studied early B-type pulsator of the last years.
Frequency analysis of observations from dedicated photometric and spectroscopic campaigns allowed to confirmed already known frequency peaks and to detect new ones (Handler et al. 2006, MNRAS, 365, 327; Desmet et al. 2009, MNRAS, 396, 1460). As a result, currently we know that at least ten pulsational frequencies of the β Cep type and one of the SPB type are excited in 12 Lac.
We present an extended identification of the mode degree, l, for all observed frequencies and complex seismic modelling of 12 Lac. Because the star rotates with a significant velocity of about 50 km/s, we consider rotational mode coupling for close p-mode frequencies and, in the case of high order g-mode, we apply the traditional approximation appropriate for slow modes. Seismic models of 12 Lac were constructed by fitting simultaneously centroid mode frequencies and corresponding values of the nonadiabatic parameter f. This approach is called complex asteorseismology and yields vastly more constraints on parameters of model and theory. Here, we take into account effects of chemical composition, opacities and non-LTE atmospheres
Frequency analysis of observations from dedicated photometric and spectroscopic campaigns allowed to confirmed already known frequency peaks and to detect new ones (Handler et al. 2006, MNRAS, 365, 327; Desmet et al. 2009, MNRAS, 396, 1460). As a result, currently we know that at least ten pulsational frequencies of the β Cep type and one of the SPB type are excited in 12 Lac.
We present an extended identification of the mode degree, l, for all observed frequencies and complex seismic modelling of 12 Lac. Because the star rotates with a significant velocity of about 50 km/s, we consider rotational mode coupling for close p-mode frequencies and, in the case of high order g-mode, we apply the traditional approximation appropriate for slow modes. Seismic models of 12 Lac were constructed by fitting simultaneously centroid mode frequencies and corresponding values of the nonadiabatic parameter f. This approach is called complex asteorseismology and yields vastly more constraints on parameters of model and theory. Here, we take into account effects of chemical composition, opacities and non-LTE atmospheres