Bibcode
Anguera Gubau, M.; Palle, P. L.; Perez Hernandez, F.; Roca-Cortés, T.
Bibliographical reference
(IAU, The Inside the Sun Colloquium, 121st, Versailles, France, May 22-26, 1989) Solar Physics (ISSN 0038-0938), vol. 128, July 1990, p. 79-90.
Advertised on:
7
1990
Citations
6
Refereed citations
3
Description
The low l solar acoustic spectrum has been measured with great accuracy
for intermediate radial order modes, n = 11-34 (Jimenez et al., 1986;
Grec et al., 1983; Palle et al., 1986). The measurement of the
frequencies of modes of lower n, up to the fundamental one, are very
important as they depart from asymptotic behavior and, therefore, put
more severe constraints on solar models. However, their amplitudes are
very low (under 2 cm/s) and when compared to the solar velocity
background noise, an S/N of 1 is obtained. Taking advantage of the fact
that lifetimes seem to be higher at lower frequencies (lower n values),
very long Doppler velocity measurements, obtained at Teide Observatory,
have been used to increase S/N, therefore, providing the possibility to
detect such modes. The frequencies observed are compared to those
predicted by a solar model (Christensen-Dalsgaard et al., 1988), using
the best equation of state yet computed (Mihalas et al., 1988).