Bibcode
Deheuvels, S.; Bruntt, H.; Michel, E.; Barban, C.; Verner, G.; Régulo, C.; Mosser, B.; Mathur, S.; Gaulme, P.; Garcia, R. A.; Boumier, P.; Appourchaux, T.; Samadi, R.; Catala, C.; Baudin, F.; Baglin, A.; Auvergne, M.; Roxburgh, I. W.; Pérez-Hernández, F.
Bibliographical reference
Astronomy and Astrophysics, Volume 515, id.A87
Advertised on:
6
2010
Journal
Citations
111
Refereed citations
82
Description
Context. The star HD 49385 is the first G-type solar-like pulsator
observed in the seismology field of the space telescope CoRoT. The
satellite collected 137 days of high-precision photometric data on this
star, confirming that it presents solar-like oscillations. HD 49385 was
also observed in spectroscopy with the NARVAL spectrograph in January
2009. Aims: Our goal is to characterize HD 49385 using both
spectroscopic and seismic data. Methods: The fundamental stellar
parameters of HD 49385 are derived with the semi-automatic software VWA,
and the projected rotational velocity is estimated by fitting synthetic
profiles to isolated lines in the observed spectrum. A maximum
likelihood estimation is used to determine the parameters of the
observed p modes. We perform a global fit, in which modes are fitted
simultaneously over nine radial orders, with degrees ranging from ℓ
= 0 to ℓ = 3 (36 individual modes). Results: Precise
estimates of the atmospheric parameters (Teff, [M/H], log g)
and of the ν sin i of HD 49385 are obtained. The seismic analysis of
the star leads to a clear identification of the modes for degrees ℓ
= 0,1,2. Around the maximum of the signal (ν ≃ 1013 μHz),
some peaks are found significant and compatible with the expected
characteristics of ℓ = 3 modes. Our fit yields robust estimates of
the frequencies, linewidths and amplitudes of the modes. We find
amplitudes of ~5.6 ± 0.8 ppm for radial modes at the maximum of
the signal. The lifetimes of the modes range from one day (at high
frequency) to a bit more than two days (at low frequency). Significant
peaks are found outside the identified ridges and are fitted. They are
attributed to mixed modes.
Based on data obtained from the CoRoT (Convection, Rotation and
planetary Transits) space mission, developed by the French Space agency
CNES in collaboration with the Science Programs of ESA, Austria,
Belgium, Brazil, Germany and Spain.Based on data obtained using the
Télescope Bernard Lyot at Observatoire du Pic du Midi, CNRS and
Université Paul Sabatier, France.
Related projects
Helio and Astero-Seismology and Exoplanets Search
The principal objectives of this project are: 1) to study the structure and dynamics of the solar interior, 2) to extend this study to other stars, 3) to search for extrasolar planets using photometric methods (primarily by transits of their host stars) and their characterization (using radial velocity information) and 4) the study of the planetary
Savita
Mathur