C.D.S. - SIMBAD4 rel 1.7 - 2019.10.20CEST12:24:08

2007A&A...470..295B - Astronomy and Astrophysics, volume 470, 295-302 (2007/7-4)

Asteroseismology of α Centauri A. Evidence of rotational splitting.


Abstract (from CDS):

Asteroseismology provides a unique tool for studying stellar interiors. Recently p modes have been detected on the bright solar-like star α Cen A thanks to high-precision radial-velocity measurements. However, a better characterisation of these p modes is clearly needed to constrain theoretical models. We observed α Cen A during five nights using the HARPS spectrograph in order to improve our knowledge of the seismic properties of this star. We performed high-precision radial-velocity sequences and computed the acoustic spectrum of α Cen A. We identify 34 p modes with angular degree l=0-3 in the frequency range 1.8-2.9mHz and amplitude range 13-48cm/s, in agreement with previous seismic studies. We find an enhancement of the frequency scatter with the angular degree l that indicates, considering the high inclination axis of α Cen A, rotational splitting and explains the low values of previously suggested mode lifetimes. We also derive new values for the small separations that take the effect of rotational splitting into account. Our seismic study of α Cen A leads to a list of now well-identified p-mode frequencies and shows the importance of taking the rotation into account in order to properly characterise the p modes even in quite short campaigns.

Abstract Copyright:

Journal keyword(s): stars: individual: α Centauri A - stars: oscillations - techniques: radial velocities

Simbad objects: 4

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Number of rows : 4

N Identifier Otype ICRS (J2000)
ICRS (J2000)
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2019
1 V* V645 Cen Fl* 14 29 42.9451234609 -62 40 46.170818907 14.21 12.95 11.13 9.45 7.41 M5.5Ve 885 0
2 * alf Cen B PM* 14 39 35.06311 -60 50 15.0992 2.89 2.21 1.33     K1V 864 1
3 * alf Cen A SB* 14 39 36.49400 -60 50 02.3737 0.96 0.72 0.01     G2V 1106 0
4 * mu. Ara PM* 17 44 08.7036342277 -51 50 02.591049123   5.85 5.15     G3IV-V 455 2

    Equat.    Gal    SGal    Ecl

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