title: Asteroseismology: oscillations on the star Procyon.
abstract: Stars are spheres of hot gas whose interiors transmit acoustic waves very efficiently. Geologists learn about the interior structure of Earth by monitoring how seismic waves propagate through it and, in a similar way, the interior of a star can be probed using the periodic motions on the surface that arise from such waves. Matthews et al. claim that the star Procyon does not have acoustic surface oscillations of the strength predicted. However, we show here, using ground-based spectroscopy, that Procyon is oscillating, albeit with an amplitude that is only slightly greater than the noise level observed by Matthews et al. using spaced-based photometry.
authors.affiliation: Laboratoire d'Astrophysique de Marseille, Traverse du Siphon, BP8, 13372 Marseille Cedex 12, France. francois.bouchy@oamp.fr
authors.forename: François
authors.initials: F
authors.lastname: Bouchy
authors.forename: André
authors.initials: A
authors.lastname: Maeder
authors.forename: Michel
authors.initials: M
authors.lastname: Mayor
authors.forename: Denis
authors.initials: D
authors.lastname: Mégevand
authors.forename: Francesco
authors.initials: F
authors.lastname: Pepe
authors.forename: Danuta
authors.initials: D
authors.lastname: Sosnowska