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

Several positions in the southern spiral arm and the interarm disk of NGC 4321 have been observed in CO (J = 1 to 0) using the NRO 45 m telescope at Nobeyama, Japan. The analysis shows evidence for streaming motions in the arms, together with an exponential radial decrease of both the integrated CO emission and the velocity width at the observed

The distribution of ionized, molecular, and atomic hydrogen in the disk and especially along the spiral arms of the Whirlpool galaxy, M51, is investigated by combining recently published maps of the H-alpha, H2, and H I surface densities, and a twofold result is reported. The existence is established of a symmetric pattern of peaks and dips in the

Since the beginning of 1990, a sodium based resonance scattering spectrometer belonging to the IRIS Network has operated at Observatorio del Teide side by side with the MkI instrument (a resonance scattering spectrometer based on potassium) from the University of Birmingham and operated since 1975. A 3 month series of simultaneous data obtained in

We present the results of infrared observations of the BL Lacertae object Markarian 501 obtained with the Telescopio Carlos Sanchez of El Observatorio del Teide, Tenerife, Spain. We report the detection of rapid infrared variations. On two nights the K (2.2 micron) magnitude shows variations which a Chi-Squared test establishes have a probability

We describe an experiment aimed at diffraction-limited imaging of astronomical sources in the 2-5/micron range. It is based on a rotation shearing interferometer that extracts the complex degree of coherence of the wavefront directly in the pupil plane. Interference fringes are produced by a Michelson interferometer in the image of the telescope