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

Author(s)
Maarten Desmet, Maryline Briquet, Gerald Handler
Abstract

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(s)
Department of Astrophysics
External organisation(s)
Katholieke Universiteit Leuven
Journal
Monthly Notices of the Royal Astronomical Society
Volume
396
Pages
1460-1472
No. of pages
13
ISSN
0035-8711
Publication date
2009
Peer reviewed
Yes
Austrian Fields of Science 2012
1030 Physics, Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/e25212f5-10a9-42ad-9be7-acc4e16da51f