ELFT HÍRADÓ

[Uhlár Karola <uhlar AT konkoly.hu>]

*MTA CSFK CSI
INTÉZETI SZEMINÁRIUM*

Elo~adó:*Sódor Ádám* (Royal Observatory of Belgium, MTA CSFK)

Elo~adás címe: **Extensive spectroscopic and photometric study of HD 
25558, a long orbital period double-lined binary with two SPB components? *
*
Kivonat:
Our project aims at investigating main-sequence g-mode pulsators in 
detail by collecting and analysing time-series of photometric and 
high-resolution spectroscopic measurements. In this talk, I introduce 
the project and the results obtained for the SPB (Slowly Pulsating B 
star) system, HD 25558. The investigation of the ~2000 spectra obtained 
at 13 observatories during 5 observing seasons, the ground-based 
multi-colour light curves and the photometric data from the MOST 
stellite revealed that this object is a double-lined spectroscopic 
binary with a very long orbital period of about 9 years. We determined 
the physical parameters of the components individually, and have found 
that both lie within the SPB instability strip. Accordingly, both 
components show line-profile variations consistent with stellar 
pulsations. Altogether, 11 independent frequencies were identified. The 
observational data do not allow the inference of a reliable orbital 
solution, thus, disentangling cannot be performed on the spectra. Since 
the lines of the two components are never completely separated, the 
analysis is very complicated. Nevertheless, pixel-by-pixel variation 
analysis of the cross-correlated line profiles was succesful, and we 
were able to attribute all the frequencies either to the primary or to 
the secondary component. Both spectroscopic and photometric 
mode-identification was also performed for several of these frequencies 
of both binary components. Comparison of the mode-identification results 
on the two components suggests some properties of a mode-selection 
mechanism in action.

Elo~adás ido~pontja: *2013. augusztus 8. (csütörtök), 14:00**
*
Elo~adás helyszíne: MTA CSFK CSI Elo~adóterme
1121 Budapest, Konkoly T. M. út 15-17.
begin:vcard
fn:Karola Uhlar
n:Uhlar;Karola
org:Konkoly Observatory
adr:;;Konkoly Thege M. u. 13-17.;Budapest;;1121;Hungary
email;internet:uhlar AT konkoly.hu
title:secretary
tel;work:+3613919322
tel;fax:+3612754668
version:2.1
end:vcard