The tip of the iceberg: The frequency content of the δ Sct star HD 50844 from CoRoT space photometry

E. Poretti, L. Mantegazza, M. Rainer, K. Uytterhoeven, E. Michel, A. Baglin, M. Auvergne, C. Catala, R. Samadi, E. Rodríguez, R. Garrido, P. Amado, S. Martín-Ruiz, A. Moya, J. C. Suárez, F. Baudin, W. Zima, M. Alvarez, P. Mathias, M. PaparóP. Pápics, E. Plachy

Research output: Conference contribution

1 Citation (Scopus)

Abstract

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 ℓ=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.

Original languageEnglish
Title of host publicationStellar Pulsation
Subtitle of host publicationChallenges for Theory and Observation - Proceedings of the International Conference
Pages435-439
Number of pages5
DOIs
Publication statusPublished - dec. 1 2009
EventInternational Conference on Stellar Pulsation: Challenges for Theory and Observation - Santa Fe, NM, United States
Duration: máj. 31 2009jún. 5 2009

Publication series

NameAIP Conference Proceedings
Volume1170
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616

Other

OtherInternational Conference on Stellar Pulsation: Challenges for Theory and Observation
CountryUnited States
CitySanta Fe, NM
Period5/31/096/5/09

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ASJC Scopus subject areas

  • Physics and Astronomy(all)

Cite this

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., ... Plachy, E. (2009). The tip of the iceberg: The frequency content of the δ Sct star HD 50844 from CoRoT space photometry. In Stellar Pulsation: Challenges for Theory and Observation - Proceedings of the International Conference (pp. 435-439). (AIP Conference Proceedings; Vol. 1170). https://doi.org/10.1063/1.3246537