A 60-night campaign on SU UMa, YZ Cnc and some secondary targets was carried out during 1988 December and 1989 January at the Observatorio del Roque de Los Muchachos (the 1988 International Time Project). The aim was to study the behaviour of these dwarf novae through their outburst cycle. Here we present the overall light curves of the main

We present measurements of the apparent rotation curves of the dusty inclined spiral NGC 2146 taken using conventional long-slit spectroscopy in the red and near-infrared. The curve measured in H(alpha) emission shows, with respect to that observed in (S III) lambda9069, a series of dips in velocity which coincide in positions with dips in the

Spectra of four lines (CI5380.3 A, MnI 5394.7 A, FeI 5930.2 A and SiI 5948.5 A) have been obtained in the quiet photosphere, at regular intervals along the polar axis and the equator. The spatially averaged spectra have been analyzed, studying the center-to-limb variation (CLV) and possible changes with the heliographic latitude of the residual

The fourth photometry campaign of the Stellar photometry International (STEPHI) network was carried out in January 1992. On this occasion, the delta Scuti-like stars BN Cnc and BU Cnc were simultaneously monitored during a three-week, three-continental run. Six and five frequency peaks are unambiguously detected for BU Cnc and BN Cnc, respectively

Frequencies of solar acoustic oscillations can be analyzed asymptotically in terms of a function determined by the sound speed in the bulk of the sun and a function determined predominantly by conditions near the solar surface. The latter depends mainly on the frequency and is related to the phase shift induced by the reflection at the solar

The SNC meteorites are samples of the Martian crust, so inferences about their origins and parent magmas are of wide planetologic significance. The EETA79001 shergottite, a basalt, contains xenoliths of pyroxene-olivine cumulate rocks which are possibly related to the ALHA77005 and LEW88516 SNC lherzolites. Olivines in the xenoliths contain