Bibcode
Poretti, E.; Mantegazza, L.; Rainer, M.; Uytterhoeven, K.; Michel, E.; Baglin, A.; Auvergne, M.; Catala, C.; Samadi, R.; Rodríguez, E.; Garrido, R.; Amado, P.; Martín-Ruiz, S.; Moya, A.; Suárez, J. C.; Baudin, F.; Zima, W.; Alvarez, M.; Mathias, P.; Paparó, M.; Pápics, P.; Plachy, E.
Referencia bibliográfica
STELLAR PULSATION: CHALLENGES FOR THEORY AND OBSERVATION: Proceedings of the International Conference. AIP Conference Proceedings, Volume 1170, pp. 435-439 (2009).
Fecha de publicación:
9
2009
Número de citas
2
Número de citas referidas
2
Descripción
It has been suggested that the detection of a wealth of very low
amplitude modes in δ Sct stars was only a matter of
signal-to-noise ratio. Access to this treasure, impossible from the
ground, is one of the scientific aims of the space mission CoRoT,
developed and operated by CNES. This work presents the results obtained
on HD 50844: the 140,016 datapoints allowed us to reach the level of
10-5 mag in the amplitude spectra. The frequency analysis of
the CoRoT timeseries revealed hundreds of terms in the frequency range
0-30 d-1. The initial guess that δ Sct stars have a
very rich frequency content is confirmed. The spectroscopic mode
identification gives theoretical support since very high-degree modes
(up to = 14) are identified. We also prove that cancellation effects
are not sufficient in removing the flux variations associated to these
modes at the noise level of the CoRoT measurements. The ground-based
observations indicate that HD 50844 is an evolved star that is slightly
underabundant in heavy elements, located on the Terminal Age Main
Sequence. The predominant term (f1 = 6.92 d-1) has
been identified as the fundamental radial mode combining ground-based
photometric and spectroscopic data.