Collecting all the data and references for a given star is generally a very time-consuming task, because the star may have many identifications. It is therefore a very first need to know the various identifications which may be used in the primary literature concerning a given star, in order to retrieve the whole set of information about the star.

The Catalogue of Stellar Identifications (CSI), which tries to solve this problem of cross-identifications, is therefore the fundamental file of the Stellar Data Center. It was created five years ago by J. Jung (1971), who was the first Director of the Center, with the help of Madame Bischoff and Madame Morin. The CSI was first a merging of some fundamental catalogues: SAO, HD, AGK2, CPC (Cape Photographic Catalogue for 1950), YZ (Yale Zone Catalogue), and GC. For each star, the information was the following:

Infrared photometry and spectroscopy of symbiotic stars is reviewed. It is shown that at wavelengths beyond lym these systems are generally dominated by the cool star’s photosphere and, indeed, are indistinguishable from ordinary late-type giants. About 25% of symbiotic stars exhibit additional emission due to circumstellar dust. Most of the dusty systems probably involve Mira variables, the dust forming in the atmospheres of the Miras. In a few cases the dust is much cooler and the cool component hotter; the dust must then form in distant gas shielded from the hot component, perhaps by an acccretion disk.

Spectroscopy at 2μm can be used to spectral type the cool components, even in the presence of some dust emission. Distances may thereby be estimated, though with some uncertainty.

Spectroscopy at longer wavelengths reveals information about the dust itself. In most cases this dust appears to include silicate grains, which form in the oxygen-rich envelope of an M star. In the case of HD 330036, however, different emission features are found which suggest a carbon-rich environment.

We study the general version of the inverse problem for planar trajectories and for autonomous dynamical systems possessing three integrals, i.e., for a given three-parametric family of curves f(x,y,a,b)=c we find the potential V(x,y) for which these curves are orbits of a unit mass. All possible cases, depending on the preassigned function f, are classified and in each case the necessary and sufficient conditions for the.existence of a solution are established. Among the examples is the case of the Keplerian conic sections which is studied in detail.

A study of the period–amplitude relation for RR Lyrae variables in the globular clusters 47 Tucanae, NGC 6441 and M55 confirms a recent finding that the period–amplitude relation for RRab stars with ‘normal’ light curves is not a function of metal abundance. Evolutionary effects are more important.

Gravitational lensing is one of a number of methods used to probe the distribution of dark mass in the Universe. On galactic scales, complementary techniques include the use of stellar kinematics, the kinematics and morphology of the neutral gas layer, kinematics of satellites, and the morphology and temperature profile of X-ray halos. These methods are compared, with emphasis on their relative strengths and weaknesses in constraining the distribution and extent of dark matter in the Milky Way and other galaxies. It is concluded that (1) the extent of dark halos remains ill-constrained, (2) halos need not be isothermal, and (3) the dark mass is probably quite flattened.

Close-binary central stars of planetary nebulae are of interest to participants in this Colloquium because of recent suggestions that the cataclysmic binaries, containing a white dwarf and a lower-main-sequence star, may be descended from such objects (e.g. Paczynski 1976; Ritter 1976; Webbink 1978; Meyer and Meyer-Hofmeister 1978; Livio, Salzman, and Shaviv 1979). The proposed scenario is. that a binary system of initially large separation (P.= 1-10 yr) forms a “common-envelope” binary after the primary has evolved to the red-giant stage and developed a degenerate core. The secondary star spirals inward inside the red-giant envelope, eventually transferring enough angular momentum to the envelope to eject it. The result is a close binary containing the hot degenerate core of the red giant and a cool main-sequence companion, surrounded by the ejected envelope, which is ionized by the hotter star. Much later, when the cool companion begins to evolve, it will start to transfer matter to the hot star (by now a white dwarf), and cataclysmic activity ensues.

Few studies concern the H alpha profile of the Be stars and it is difficult to do a fine analysis of the line structure, and of its variations from the results obtained with different resolutions and accuracies.

Then, it was useful to apply modern technics for the observation of this line to get an homogeneous material, sensitive enough to show fast variations of the order of few minutes because an accurate photometry is available using linear response receivers.

Our 2dF Fornax Cluster Spectroscopic Survey (FCSS) and follow-up work in the Virgo Cluster have shown that the cores of both galaxy clusters contain a previously-unknown class of object, ultra-compact dwarf (UCD) galaxies. We present high resolution spectroscopy and deep multicolor imaging to show that these enigmatic objects are dynamically distinct from both globular clusters (GCs) and nucleated dwarf galaxies (dE,Ns). Our hypothesis for their origin may explain the observed high “specific frequency” of GCs in central cluster galaxies.

The objects from which the structure of the galactic halo may be derived by optical means are the extreme population II objects such as RR Lyrae variables with periods longer than 0-4 days, the sub-dwarfs, globular clusters, stars similar to those found in globular clusters such as the bright red giants, and the blue stars found in the galactic polar regions. The longperiod variables with periods shorter than 200 days and the ordinary highvelocity stars are now regarded as belonging to an intermediate population II, somewhat younger than the halo population II proper.

The main investigations of the local magnetic field are reviewed and are found to contain some conflict in interpretation. At radio wavelengths, studies have been made using both the Faraday rotation of the polarized radiation from extragalactic sources and pulsars, and the polarization of the galactic background radiation. With the former type of observation, although more data are available for extragalactic sources, any interpretation may be complicated by the influence of distant field structure. The results are consistent with a large-scale field parallel to the galactic plane, with a field strength of about 2 µG, and which is directed towards l=90°. This field contains irregularities in direction and strength on a scale of about 100–200 pc. The polarization of galactic background radiation may yield the most detailed information about the local field structure – the results to date show loops of magnetic fields extending along the radio spurs.

The interpretation in terms of small-scale irregularities embedded in a large-scale field parallel to the galactic plane differs from that proposed to explain the optical polarization of starlight, in which a helical field configuration near the Sun was preferred to a more disordered pattern.

We present the detection of molecular gas using CO(1–0) line emission and followup Hα imaging observations of galaxies located in nearby voids. The CO(1–0) observations were done using the 45m telescope of the Nobeyama Radio Observatory (NRO) and the optical observations were done using the Himalayan Chandra Telescope (HCT). Although void galaxies lie in the most underdense parts of our universe, a significant fraction of them are gas rich, spiral galaxies that show signatures of ongoing star formation. Not much is known about their cold gas content or star formation properties. In this study we searched for molecular gas in five void galaxies using the NRO. The galaxies were selected based on their relatively higher IRAS fluxes or Hα line luminosities. CO(1–0) emission was detected in four galaxies and the derived molecular gas masses lie between (1 - 8)×109M⊙. The Hα imaging observations of three galaxies detected in CO emission indicates ongoing star formation and the derived star formation rates vary between from 0.2 – 1.0 M7odot; yr-1, which is similar to that observed in local galaxies. Our study shows that although void galaxies reside in underdense regions, their disks may contain molecular gas and have star formation rates similar to galaxies in denser environments.

The Universe is full of galaxies of various shapes; some galaxies have spiral arms and others don’t. Why do galaxies show such diversity? How were galaxies formed and evolved? Galaxies are thought to grow by interacting and merging with other galaxies, and the galaxy mergers may be the key process creating the variety. GALAXY CRUISE is the first citizen science project conducted by National Astronomical Observatory of Japan (NAOJ) to unlock galaxies’ secrets using the big observational data. We made the superior quality big data taken by the Subaru Telescope accessible to the public and invited them to participate in data classification. Here we report how we designed the website and its first-year progress.

We review recent insights into the dynamics of the solar convection zone obtained from global numerical simulations, focusing on two recent developments in particular. The first is quasi-cyclic magnetic activity in a long-duration dynamo simulation. Although mean fields comprise only a few percent of the total magnetic energy they exhibit remarkable order, with multiple polarity reversals and systematic variability on time scales of 6-15 years. The second development concerns the maintenance of the meridional circulation. Recent high-resolution simulations have captured the subtle nonlinear dynamical balances with more fidelity than previous, more laminar models, yielding more coherent circulation patterns. These patterns are dominated by a single cell in each hemisphere, with poleward and equatorward flow in the upper and lower convection zone respectively. We briefly address the implications of and future of these modeling efforts.

The impressive transition from an era of scientific data scarcity to an era of overproduction has become particularly noticeable in archaeoastronomy. The collection of astronomical information about prehistoric societies allows the accumulation of global data on: – the oldest traces of astronomical activity on Earth, emotional and rational display of celestial phenomena in astronomical folklore, “folk astronomy” and timekeeping, in fine arts and architecture, in everyday life; – the most ancient applied “astronomy” – counting the time by lunar phases, accumulation and storage of ancient databases in drawings and pictographic compositions in caves and artificially constructed objects; – “horizon” astronomy as an initial form of observational cult astronomy, preserved only in characteristic material monuments (the oldest cult observatories) with indisputable astronomical orientations. The report shows the importance of collecting the maximum number of artifacts and monuments from prehistory associated with the early emergence of interest in celestial phenomena. Spiritual, emotional and rational (including practical) needs that have aroused interest in Heaven are discussed. The huge variety of activities in realizing the regularity (cyclicity) of celestial phenomena as a stimulus for their use for orientation in space and time is shown.

The Kelvin-Helmholtz instability (KHI) could be a potential source for some of the Alfvénic fluctuations observed in the solar wind. The nonlinear evolution of KHI is examined in 2+1 dimensions in the context of magnetohydrodynamics. We derived a nonlinear Schródinger equation (NLSE) and we obtained soliton solutions of this 2+1 dimensions NLSE.

One explanation for the disparity between Cold Dark Matter predictions of galaxy numbers and observations could be that there are numerous dark galaxies in the Universe. These galaxies may still contain baryons, but no stars, and may be detectable in the 21cm line of atomic hydrogen. In this paper we describe a numerical model of the galaxy population and predict what might be found in blind 21cm surveys. We describe the detection of a dark galaxy candidate (VIRGOHI21) and discuss a model of its origin.

We present a matched-filter, surface density map of the “300 km/s” stream recently discovered in the vicinity of the ultrafaint dwarf galaxy Segue 1.