λ Bootis stars: Current status and new insights from Spitzer

Autor(en)

Inga Kamp, Juan Rafael Martinez-Galarza, Ernst Paunzen, Katherine Y.L Su, András Gáspár, George H. Rieke

Abstrakt

The group of ? Bootis type stars comprises late B- to early F-type, Population I objects which are basically metal weak, in particular the Fe group elements, but with the clear exception of C, N, O and S. We present a spectroscopical definition for the group membership by using the light element versus metal abundance pattern. One of the current explanations for the ? Bootis peculiarity is the accretion of interstellar material as the star travels through a diffuse interstellar cloud. We will review this hypothesis in the context of ESO high resolution spectra and Spitzer imaging and photometry. The NaI D lines provide simultaneously stellar abundances and physical properties of interstellar material along the line of sight. The new Spitzer results shed light on the presence of dust around these stars, its composition and geometric distribution.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Leiden University, University of Arizona

Journal

Contributions of the Astronomical Observatory Skalnaté Pleso

Band

38

Seiten

147-156

Anzahl der Seiten

10

ISSN

1335-1842

Publikationsdatum

2008

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/2cecdaa2-d0ee-4646-a854-5a6f0f13f5be