We discuss the “rotation” curves of SB0 galaxies with self-consistent models constructed with Schwarzschild’s method. Their distribution functions are compared with that of N-body simulations.

A new research for the secular drift of the Earth's pole was made based on nine long sequences of latitude observations and led to the following conclusions.

1. 1. During this century, the Earth's pole has been moving with a mean rate of about 0″.0016/yr along the meridian about 70° (W). This drift rate is much less than the 0″.0035/yr derived from the ILS sequence.

2. 2. Relative to the North American continent, the Ukiah station located on the west coast of the U.S. shows a local drift of about 6 cm/yr northward, which coincides well with that determined by new techniques.

3. 3. Referring to the Europe-Asia plate, the whole North American continent shows a drift northward with a rate of about 8 cm/yr. The Mediterranian shows a similar drift of about 6 cm/yr. Perhaps these drifts are the consequences of plate motion and/or deflection of local vertical. It is useful for ascertaining the sources of the drifts to intercompare longer sequences observed with different techniques, including classical and new ones.

4. 4. Three of five ILS stations, Ukiah, Gaithersburg, and Carloforte, show significant local drifts. Therefore, the Conventional International Origin (CIO), which is defined by the 1903.0 mean latitudes of five ILS stations, is far from fixed on the Earth's surface. It is necessary to re-define an origin of the pole of the Conventional Terrestrial System (CTS).

5. 5. The quasi-30-year libration showed by the ILS data is not the real pattern of the Earth's polar motion, but results from both the irregular polar motion over some period and the local motion of Ukiah.

We compare the relative merits of four different types of instrument for tridimensional spectrometry at visible and ultraviolet wavelengths: the echelle and long-slit spectrographs and two types of Fourier transform spectrometer (conventional scanning and fixed tilt spatially heterodyned). Each of these instruments requires different spatial and spectral scanning modes. It is shown that in certain limiting conditions all four are equally efficient, but that they differ in other important characteristics.

We have obtained optical recombination-line abundances for the third-row element magnesium in ten planetary nebulae. The nebulae in our sample include four (NGC 7009, NGC 6153, M 2–36 and M 1–42) for which we have previously found very large enhancements, relative to solar, in the recombination line abundances of the second-row elements carbon, nitrogen, oxygen and neon (Liu et al. 1995, Liu et al. 2000, Liu et al. 2001). Nebular temperature fluctuations appear unable to account for these effects. However, models that invoke high-density clumps, particularly clumps which are hydrogen-deficient, appear more viable as an explanation for the high recombination line abundances that are observed (see Liu et al. 2000 for more details). While it may be possible to appeal to astrophysical nucleosynthetic processes to enhance the CNONe second-row elements in AGB stars, such effects are not expected to modify the abundances of third-row elements such as magnesium. We have therefore measured and dereddened the intensities of the 4481 Å 4f-3d line of Mg II, relative to Hβ, in order to investigate whether magnesium recombination line abundances are enhanced or not.

The extent and nature of molecular material in the outer Galaxy (R > R⊙) has been an open, interesting question since the discovery of molecular material in the outer Galaxy (Kutner & Mead, 1981). From large scale CO surveys, two estimates of the total molecular mass have been made with the same result, M(H2) = 6 × 108 M⊙ (Wouterloot et al., 1990), (Digel et al., 1990). Both estimates have a strong bias towards large, star forming (warm) clouds. Wouterloot et al. used the IRAS point source catalog as a finder chart for their observations and the inner Galaxy mass distribution to scale their result. Digel et al. conducted an unbiased survey with a large (8.8 arcminute) beam which underestimated the amount of material in small clouds due to the effects of beam dilution.

At the Institute for Theoretical Astronomy we have formed a library containing about 120 standard computer programmes. They include calculation of rectangular coordinates and velocities from elements, Lagrangian interpolation, and orbit improvement by the Eckert-Brouwer method. For the investigation of the motions of the minor bodies of the solar system we have constructed a programme for integration with a variable step and making allowance for perturbations by all the major planets and for nongravitational effects. The calculation of the perturbations is carried out using Herrick's vector parameters by the method of variation of arbitrary constants. The programme has been used for studying the motion of P/Encke.

The relations between the physical parameters of the RRab stars and the Fourier parameters of their light curves have been reanalyzed on the basis of new CCD data. We show that the absolute magnitude MV and the dereddened color indices (B − V)0, (V − I)0 are linear functions of the period and of the A1 Fourier amplitude of the V light curve. Due to the large datasets, we are able to test the consistency of the formulae on independent sets. The present results are in good or fair agreement with our previous studies, despite the fewer number of significant parameters entering in the revised formulae.

Although the subject of this meeting is triggered star formation in a turbulent interstellar medium, it remains unsettled what role magnetic fields play in the star formation process. This paper briefly reviews star formation model predictions for the ratio of mass to magnetic flux, describes how Zeeman observations can test these predictions, describes new results – an extensive OH Zeeman survey of dark cloud cores with the Arecibo telescope, and discusses the implications. Conclusions are that the new data support and extend the conclusions based on the older observational results – that observational data on magnetic fields in molecular clouds are consistent with the strong magnetic field model of star formation. In addition, the observational data on magnetic field strengths in the interstellar medium strongly suggest that molecular clouds must form primarily by accumulation of matter along field lines. Finally, a future observational project is described that could definitively test the ambipolar diffusion model for the formation of cores and hence of stars.

The properties of the different types of QSO absorption systems are briefly summarized. An overview is given of the potential applications of absorption lines in cosmology. Recent work on the cosmological evolution of the different types of absorbers is discussed. The physical properties of the intergalactic medium are discussed in the light of recent work on the “Lyman alpha clouds”. The uses of the lines for studies of the evolution of clustering in the Universe are described. Recent puzzling results on common absorption in pairs of QSOs, particularly Q1037–2704 and Q1038–2712, are summarized.

We present results of thermal and vibrational stability analysis for 1 M⊙ white dwarf models corresponding to various accretion rates ≳ 10−11 M⊙/y. Accretion is assumed to be spherically symmetric and stationary. Thermal instability due to nuclear burning of hydrogen (at lower accretion rates) and helium (at higher rates) was found. At medium rates two growing thermal modes are simultaneously present. Vibrational instability was found for all models except those corresponding to highest accretion rates. The excitation rates for some nonradial g-modes are at least 3 orders of magnitude higher than those for radial pulsations. These rates are also higher than the excitation rates for thermal modes in certain range of accretion rates corresponding to high luminosities and effective temperatures. Among objects in which these instabilities may be important are symbiotic stars and nuclei of planetary nebulae.

The radio continuum emission of the Milky Way and nearby galaxies can be decomposed into a central region, a clumpy “thin disk”, concentrated in the spiral arms, and a smooth “thick disk” (or flattened “halo”). The emissivity ratio of the two disks seems to be related to the magnetic field properties: Galaxies with strong radio spiral arms reveal a highly ordered field following the arm direction, while galaxies with diffuse disks contain a less ordered, smoothly distributed field. The degree of uniformity of the field seems to correlate with the total optical luminosity. The average magnetic field in the Milky Way is weak and turbulent compared to most of the nearby galaxies observed so far.

The distribution of matter condensing out of cooling flows in clusters of galaxies and individual elliptical galaxies has been studied using X-ray data and is found to resemble the expected mass profiles of the underlying galaxies. Most of the cooled gas must create objects of high mass-to-light ratio, although some more normal stars are produced. Cooling flows provide an observable mechanism for the continual formation of dark matter around galaxies. Since the conditions at galaxy formation are similar to those in cooling flows if the gas reaches the virial temperature, we suggest that they are local models of galaxy formation.

I consider it a great honour to give this talk today in place of my friendand colleague, the late Dr. S. F. Smerd, who died last December. All who knew Steve miss his enthusiasm and keen insight into solar physics.

Relativistic spin effects involved in the Earth-Moon dynamics are reviewed. They enclose: (i) the coordinate system effects, and (ii) the relativistic physical librations. The geodetic precession is the only relativistic spin phenomenon which has been firmly detected so far. The best candidates of the effects which might be detected in the forthcoming period are the lunar physical librations and coordinate nutations. As for the latter, however, a fine cancellation between the geodetic and the Lense-Thirring coordinate effects results in decreasing their amplitude just below the possibility of the Lunar Laser Ranging technology.

Local Group galaxies allow us to test some properties of massive star evolution which are inaccessible in our Galaxy, in particular the effects of different metallicities. Thus, after showing that we still do not know the exact process by which massive stars are formed, we examine the differences in the distributions of O-stars, blue and red supergiants and WR stars in the Local Group. The number ratios WR/O and WN/WC are well accounted for by stellar models in which the mass-loss rates depend on the metallicity, Z, as predicted by stellar wind theories. The number ratio of red supergiants to WR stars is growing for decreasing Z. Although this behaviour is qualitatively well explained, the models need some extra mixing to fit the observational data. The same is true for the explanation of the He- and N-excesses in O, B and A supergiants. Rotation and related mixing processes certainly play a major role in massive star evolution. The relative number of Be-stars is higher at lower Z, which suggests that rotation is faster, also with more mixing, in small, irregular low-metallicity galaxies.

Since the start of the SoHO mission, EIT -the Extreme ultraviolet Imaging Telescope- offers a global view of the solar corona over the whole rising phase of the current activity cycle. Such a dataset is unprecedented. We give here the current results of an on-going investigation over the entire EIT archive. In the Fe XV images (2 MK), the on-disk and off-disk intensity distributions have been evaluated, and their evolution is described. Additionally, we developed an image processing technique that extracts the smallest detectable features. The cosmic ray hits are statistically disentangled from the solar point-like phenomena, and the trends in both rates are assessed.

For the purposes of this talk I will take “high resolution” to mean 1 milliarcsecond (mas). Only objects of high surface brightness when averaged over 1 mas are considered; as H. McAlister will discuss stellar applications, I will speak only about nonstellar applications.