An asteroseismic study of the ? Cephei star 12 Lacertae: multisite spectroscopic observations, mode identification and seismic modelling

Autor(en)

Maarten Desmet, Maryline Briquet, Gerald Handler

Abstrakt

We present the results of a spectroscopic multisite campaign for the ? Cephei star 12 (DD) Lacertae. Our study is based on more than thousand high-resolution high S/N spectra gathered with eight different telescopes in a time span of 11 months. In addition, we make use of numerous archival spectroscopic measurements. We confirm 10 independent frequencies recently discovered from photometry, as well as harmonics and combination frequencies. In particular, the slowly pulsating B-stars (SPB)-like g-mode with frequency 0.3428d-1 reported before is detected in our spectroscopy. We identify the four main modes as (l1, m1) = (1, 1), (l2, m2) = (0, 0), (l3, m3) = (1, 0) and (l4, m4) = (2, 1) for f1 = 5.178964d-1, f2 = 5.334224d-1, f3 = 5.066316d-1 and f4 = 5.490133d-1, respectively. Our seismic modelling shows that f2 is likely the radial first overtone and that the core overshooting parameter ?ov is lower than 0.4 local pressure scale heights.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Katholieke Universiteit Leuven

Journal

Monthly Notices of the Royal Astronomical Society

Band

396

Seiten

1460-1472

Anzahl der Seiten

13

ISSN

0035-8711

Publikationsdatum

2009

Peer-reviewed

Ja

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/e25212f5-10a9-42ad-9be7-acc4e16da51f