SIAMOIS: Seismic Interferometer to Measure Oscillations in the Interior of Stars

¹ LESIA, Observatoire de Paris, CNRS UMR 8109, 92195 Meudon, France
² Observatoire de Paris, LESIA, IAP, IAS, UNSA/LUAN, OMP/LATT, OCA, SESO, France

Abstract

SIAMOIS is a project devoted to ground-based asteroseismology, involving a small collector and an instrument to be installed at the Dome C Concordia station in Antarctica. After the space project CoRoT, SIAMOIS will provide unique Doppler information on G and K type bright stars on the main sequence. Spectrometric observations with SIAMOIS will be able to detect oscillation modes that cannot be analyzed in photometry, and will be less affected by stellar activity noise. The SIAMOIS concept is based on Fourier Transform interferometry. Such a principle leads to a small instrument designed and developed for the harsh conditions in Antarctica. The instrument will be fully automatic, with no moving parts, and a very simple initial set up at Dome C. Dome C appears to be the ideal place for ground-based asteroseismic observations. The unequalled weather conditions yield a duty cycle as high as 90% over 3 months, as was observed during the 2006 wintering. This high duty cycle, a crucial point for asteroseismology, is comparable to the best space-based observations. Long time series (up to 3 months) will be possible, thanks to the long duration of the polar night. SIAMOIS can be seen as one of the very first astronomical projects to be conducted at Dome C. Its scientific programme will take full advantage of the unique quality of this site, and will constitute a necessary first step in preparation of future more ambitious programmes requiring more sophisticated instrumentation and larger collectors.