The low L solar p-mode spectrum at maximum and minimum solar activity

Anguera Gubau, M.; Palle, P. L.; Perez Hernandez, F.; Regulo, C.; Roca-Cortés, T.
Referencia bibliográfica

Astronomy and Astrophysics (ISSN 0004-6361), vol. 255, no. 1-2, p. 363-372.

Fecha de publicación:
2
1992
Número de autores
5
Número de autores del IAC
5
Número de citas
86
Número de citas referidas
67
Descripción
Velocity measurements of disc integrated sunlight obtained at the Observatorio del Teide (Izana) from 1980 throughout 1989 are used to find the frequencies and amplitudes of each p-mode with l less than 4 and n between 5 and 33. The 32 best monthly spectra obtained are averaged in two separate groups corresponding to periods with solar activity maximum and minimum. The observational p-mode frequencies differ from those predicted by standard solar models by more than their errors; however the frequency separations are in reasonable agreement. Such parameters, which give information about the core of the sun, can be determined for the maximum and the minimum of solar activity cycle. Significant differences between maximum and minimum on these parameters have not been found and they agree well with the predictions of standard models although the small observational errors achieved allow distinguishing among them. It is also found that the energy of the modes is smaller at the maximum than during the minimum of solar activity, telling us a bit more about the structure and efficiency of the sunlayers in exciting these modes.