Frequency differences between high-order p-modes of two stellar models, both with the mass and luminosity of the sun, are compared with results of asymptotic theory. The computed relative differences are closely approximated by averages of the relative sound-speed differences, weighted by the local sound travel-time, over the regions where the

Since 1984 the measurements of a quadruple photometer sited at the Observatorio del Teide (Izana, Tenerife) made it possible to identify the p-mode luminosity spectrum with simultaneous velocity observations. Comparing this data, the adiabatic behavior of solar atmosphere and theoretical expectations from solar models were tested. In order to

Low degree l=0-2 solar p-modes were detected with the SLOT instruments at Izana and Baja California. The main source of noise for these ground based observations is in the terrestrial atmosphere. However, the data acquisition system still has to have very low intrinsic noise. It is shown how this is achieved in the SLOT instruments. Design and

High-speed photometric observations were performed of the Ap stars HD62140 (49 Cam), HD81009, and HD22374 for more than 60 hr in Oct. and Dec. 1986. Photometric measurements in the B band were reduced and the residuals obtained were subjected to a harmonic analysis, searching for periodicities in the range of a few minutes to 2 hr. There is

Rotational splitting measurements of less than 5 p-modes are calculated using different sources of data. For l=1, data obtained from years 1981 to 1985 is used to find out the stretches where each particular mode remains excited; then its splitting is measured and the mean found. Cross-correlation of power spectra confirms these finding, and this

The Delta Scuti variable 63 Her was observed during 21 nights at two observatories (Observatorio del Teide, Tenerife Island, Spain and Observatorio Astronomico Nacional de San Pedro Martir in Baja California, Mexico). Six frequencies of pulsation are unambiguously detected, among which the fundamental radial mode, two non radial pressure-like modes