Bibcode
Fierry Fraillon, D.; Pallé, P. L.; Golf Team
Referencia bibliográfica
Structure and Dynamics of the Interior of the Sun and Sun-like Stars SOHO 6/GONG 98 Workshop Abstract, June 1-4, 1998, Boston, Massachusetts, p. 911
Fecha de publicación:
0
1998
Número de citas
1
Número de citas referidas
1
Descripción
The solar activity, following an eleven years cycle, modifies the
physical properties of the resonant cavity where the oscillation
acoustic modes are trapped. Its effect on p-modes frequencies is a
positive shift as the solar activity grows from a minimum to a maximum
(Fossat et al. 1987, Pallé et al. 1989, Elsworth et al. 1990). A
continuous set of observation like the Golf data set, fron the 11 April
1996 to the 3 January 1998, allows a study of the p-modes frequency
shift during a minimal solar activity. We selected 3 power spectra with
differents MPSI magnetic index and with a 36 days duration of
observation according to the evolution time of the magnetic index. Then,
we used a mode to mode cross-correlation technique in order to estimate
an individual shift of the mean frequency of n = 13 to 24, l = 0 to 3
modes by fitting a Lorentzian profile on the cross-correlation. We also
investigate for a global frequency shift using the same
cross-correlation technique. The results show the evidence of the
frequency stability of p-modes in the 19-months GOLF data set even with
the light increase of the solar activity since September 1998.