A spectroscopic survey for λ Bootis stars II. The observational data

Author(s)
Ernst Paunzen, B Duffee, Ulrike Heiter, Rainer Kuschnig, Werner Wolfgang Weiss
Abstract

? Bootis stars comprise only a small number of all A-type stars and are characterized as nonmagnetic, Population I, late B to early F-type dwarfs which show significant underabundances of metals whereas the light elements (C, N, O and S) are almost normal abundant compared to the Sun. In the second paper on a spectroscopic survey for ? Bootis stars, we present the spectral classifications of all program stars observed. These stars were selected on the basis of their Strošmgren uvbyß colors as ? Bootis candidates. In total, 708 objects in six open clusters, the Orion OB1 association and the Galactic field were classified. In addition, 9 serendipity non-candidates in the vicinity of our program stars as well as 15 Guide Star Catalogue stars were observed resulting in a total of 732 classified stars. The 15 objects from the Guide Star Catalogue are part of a program for the classification of apparent variable stars from the Fine Guidance Sensors of the Hubble Space Telescope. A grid of 105 MK standard as well as "pathological" stars guarantees a precise classification. A comparison of our spectral classification with the extensive work of Abt & Morrell (1995) shows no significant differences. The derived types are 0.23 ‘ 0.09 (rms error per measurement) subclasses later and 0.30 ‘ 0.08 luminosity classes more luminous than those of Abt & Morrell (1995) based on a sample of 160 objects in common. The estimated errors of the means are ‘ 0.1 subclasses. The characteristics of our sample are discussed in respect to the distribution on the sky, apparent visual magnitudes and Strošmgren uvbyß colors.

Organisation(s)
Department of Astrophysics, Vienna University Computer Center
External organisation(s)
Keele University, University of British Columbia (UBC)
Journal
Astronomy & Astrophysics
Volume
373
Pages
625-632
No. of pages
8
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361:20010630
Publication date
2001
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/e9ce6616-29ab-4bfd-b156-70392c318155