Preparing the COROT space mission: Incidence and characterisation of pulsation in the lower instability strip

Author(s)
Ennio Poretti, Rafael Garrido, Pedro J. Amado, Katrien Uytterhoeven, Gerald Handler, Roi Alonso, Sven Martin, Conny Aerts, Claude Catala, Marie J. Goupil, Eric Goupil, Luciano Mantegazza, P Mathias, M L Pretorius, Juan Antonio Belmonte, Antonio Claret, Eloy Rodriguez, Juan Carlos Suarez, F F Vuthela, Werner Wolfgang Weiss, Dominique Ballereau, Jean Claude Bouret, S. Charpinet, T Hua, Theresa Rank-Lüftinger, Nicole Nesvacil, C van 'T Veer-Menneret
Abstract

By pursuing the goal to find new variables in the COROT field-of-view we characterised a sample of stars located in the lower part of the instability strip. Our sample is composed of stars belonging to the disk population in the solar neighbourhood. We found that 23% of the stars display multiperiodic light variability up to a few mmag in amplitude, i.e., easily detectable on a single night of photometry, uvbyß photometry fixed most of the variables in the middle of the instability strip and high-resolution spectroscopy established that they have v sin; i > 100 km s-1. An analysis of the RodriŽguez & Breger (2001) sample (d Sct stars in the whole Galaxy) shows slightly different features, i.e., most d Sct stars have a 0.05-mag redder (b - y)o index and lower v sin i values. Additional investigation in the open cluster NGC 6633 confirms the same incidence of variability, i.e., around 20%. The wide variety of pulsational behaviours of d Sct stars (including unusual objects such as a variable beyond the blue edge or a rapidly rotating high-amplitude pulsator) makes them very powerful asteroseismic tools to be used by COROT. Being quite common among bright stars, d Sct stars are suitable targets for optical observations from space.

Organisation(s)
Department of Astrophysics
External organisation(s)
INAF Osservatorio Astronomico di Brera, Instituto de Astrofísica de Andalucía (CSIC), Katholieke Universiteit Leuven, Institute of Astrophysics of the Canary Islands, Federal Institute for Materials Research and Testing, Université de recherche Paris Sciences et Lettres, Université Côte d'Azur, University of Cape Town, South African Astronomical Observatory (SAAO), Université de Provence Aix-Marseille I, Observatoire Midi-Pyrénées
Journal
Astronomy & Astrophysics
Volume
406
Pages
203-211
No. of pages
9
ISSN
0004-6361
DOI
https://doi.org/10.1051/0004-6361:20030711
Publication date
2006
Peer reviewed
Yes
Austrian Fields of Science 2012
103003 Astronomy
Portal url
https://ucrisportal.univie.ac.at/en/publications/3c091bf6-c05a-4ba6-acc7-0d53ec2cbd47