A multi-site campaign to measure solar-like oscillations in Procyon. II. mode frequencies

Timothy R. Bedding, Hans Kjeldsen, Tiago L. Campante, Thierry Appourchaux, Alfio Bonanno, William J. Chaplin, Rafael A. Garcia, Milena Martić, Benoit Mosser, R. Paul Butler, Hans Bruntt, Lszló L. Kiss, Simon J. O'Toole, Eiji Kambe, Hiroyasu Ando, Hideyuki Izumiura, Bun'Ei Sato, Michael Hartmann, Artie Hatzes, Caroline BarbanGabrielle Berthomieu, Eric Michel, Janine Provost, Sylvaine Turck-Chièze, Jean Claude Lebrun, Jerome Schmitt, Jean Loup Bertaux, Serena Benatti, Riccardo U. Claudi, Rosario Cosentino, Silvio Leccia, Søren Frandsen, Karsten Brogaard, Lars Glowienka, Frank Grundahl, Eric Stempels, Torben Arentoft, Michaël Bazot, Jørgen Christensen-Dalsgaard, Thomas H. Dall, Christoffer Karoff, Jens Lundgreen-Nielsen, Fabien Carrier, Patrick Eggenberger, Danuta Sosnowska, Robert A. Wittenmyer, Michael Endl, Travis S. Metcalfe, Saskia Hekker, Sabine Reffert

Research output: Contribution to journalArticlepeer-review


We have analyzed data from a multi-site campaign to observe oscillations in the F5 star Procyon. The data consist of high-precision velocities that we obtained over more than three weeks with 11 telescopes. A new method for adjusting the data weights allows us to suppress the sidelobes in the power spectrum. Stacking the power spectrum in a so-called échelle diagram reveals two clear ridges, which we identify with even and odd values of the angular degree (l = 0 and 2, and l = 1 and 3, respectively). We interpret a strong, narrow peak at 446μHz that lies close to the l = 1 ridge as a mode with mixed character. We show that the frequencies of the ridge centroids and their separations are useful diagnostics for asteroseismology. In particular, variations in the large separation appear to indicate a glitch in the sound-speed profile at an acoustic depth of 1000s. We list frequencies for 55 modes extracted from the data spanning 20 radial orders, a range comparable to the best solar data, which will provide valuable constraints for theoretical models. A preliminary comparison with published models shows that the offset between observed and calculated frequencies for the radial modes is very different for Procyon than for the Sun and other cool stars. We find the mean lifetime of the modes in Procyon to be 1.29+0.55-0.49days, which is significantly shorter than the 2-4days seen in the Sun.

Original languageEnglish (US)
Pages (from-to)935-949
Number of pages15
JournalAstrophysical Journal
Issue number2
StatePublished - 2010


  • Stars: individual (Procyon A)
  • Stars: oscillations

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


Dive into the research topics of 'A multi-site campaign to measure solar-like oscillations in Procyon. II. mode frequencies'. Together they form a unique fingerprint.

Cite this