A spectroscopic study of southern (candidate) gamma Doradus stars: I. Time series analysis

Author(s): Peter De Cat, Laurent Eyer, J Cuypers, Conny Aerts, Bart Vandenbussche, Katrien Uytterhoeven, K Reyniers, Katrien Kolenberg, Martin A. T. Groenewegen, G Raskin, Thomas Maas, Slobodan Jankov
Abstract: We present the results of a spectroscopic study of 37 southern (candidate) ? Doradus stars based on eŽchelle spectra. The observed spectra were cross-correlated with the standard template spectrum of an F0-type star for easier detection of binary and intrinsic variations. We identified 15 objects as spectroscopic binaries, including 7 new ones, while another 3 objects are binary suspects. At least 12 objects show composite spectra. We could determine the orbital parameters for 9 binaries, of which 4 turned out to be ellipsoidal variables. For 6 binaries, we estimated the expected time-base of the orbital variations. Clear profile variations were observed for 17 objects, pointing towards stellar pulsation. For 8 of them, we have evidence that the main spectroscopic and photometric periods coincide. Our results, in combination with prior knowledge from the literature, lead to the classification of 10 objects as new bona fide ? Doradus stars, 1 object as a new bona fide d Scuti star, and 8 objects as constant stars. Finally, we determined the projected rotational velocity by two independent methods. The resulting v sin i values range from 3 to 135 km s-1. For the bona fide ? Doradus stars, the majority has v sin i below 60 km s-1. Œ ESO 2006.
Organisation(s): Department of Astrophysics
External organisation(s): Katholieke Universiteit Leuven, Université de Genève, Royal Observatory of Belgium, Université Côte d'Azur
Journal: Astronomy & Astrophysics
Volume: 449
Pages: 281-292
No. of pages: 12
ISSN: 0004-6361
Publication date: 2006
Peer reviewed: Yes
Austrian Fields of Science 2012: 103003 Astronomy
Portal url: https://ucrisportal.univie.ac.at/en/publications/41fd9667-a5c5-4b0e-b643-1252ed0f559a

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