λ Bootis stars: Current status and new insights from Spitzer

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

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(s)
Department of Astrophysics
External organisation(s)
Leiden University, University of Arizona
Journal
Contributions of the Astronomical Observatory Skalnaté Pleso
Volume
38
Pages
147-156
No. of pages
10
ISSN
1335-1842
Publication date
2008
Austrian Fields of Science 2012
1030 Physics, Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/2cecdaa2-d0ee-4646-a854-5a6f0f13f5be