Variable stars and stellar evolution Symposium N° 67 held in Moscow U.S.S.R. july 29 to august 4 1974 Sommaire: Flare stars and T tauri stars; R Coronae borealis stars; Symbiotic stars .

Colloquia and symposia have almost become a tradition among the variable-star astronomers; those held more or less regularly at Bamberg and Budapest have become well known. For a change, this time the organizing committee of Commission 27 decided to hold an LA. U. symposium in Moscow and to adopt as a special topic the relation between variable stars and the evolution of stars and stellar systems. This symposium, No. 67 in the LA. U. series, was prepared by two committees, a by B. V. Kukarkin, and a local one with V. A. Ambartsumian scientific one chaired as chairman, and G. S. Khromov as executive secretary. It was held in Moscow at the Physical and Astronomical Institutes of the Lomonosov University from July 29 to August 4, 1974. The symposium was opened with three short welcoming speeches by V. A. Ambartsu­ mian, J. M. Ternov (vice-rector of Moscow University), and B. V. Kukarkin. All three stressed the importance of the study of variable stars in connection with the evolution of stars and stellar systems, the role of the Russian astronomers in these studies, and the necessity of international cooperation.

1/Flare Stars and T Tauri Stars.- Flare Stars in Star Clusters and Associations (Review).- Solar Neighborhood Flare Stars (Review).- Flares of Red Dwarf Stars and Solar Activity (Review).- An Observational Approach to Stellar Evolution; Flare Stars and Related Objects (Review; abstract).- On Variations in the Flare Activity of V 1054 Oph.- High-Speed Photometry of Cluster Flare Stars.- Flare Colours and Luminosities.- A Possible Mechanism of Stellar Flares.- The Physics of Flare Stars.- Comparison of UV Ceti Flares with Solar Flares (Abstract).- T Tauri and FU Ononis Stars (Review).- Possible Groupings of Irregular (Orion) Variables (Abstract).- Spectroscopic and Photometric Observations of VX Cas.- Infrared Spectra of T Tau Stars and Related Objects.- Photographic Photometry of V 1057 Cygni.- 2/R Coronae Borealis Stars.- The R Coronae Borealis Type Variables (Review).- The So-Called Antiflare Stars (Abstract).- Some Statistics of Southern R Coronae Borealis Variables (Abstract).- Physical Interpretation of Light Curves of R Coronae Borealis-Type Stars.- Spectral and Polarimetric Investigation of RCB Stars (Abstract).- Observations of R CrB and XX Cam.- Circumstellar Dust Shells.- Cool Carbon Stars in Open Clusters (Abstract).- On the Nature of Maser Sources in Infrared Stars.- Autocorrelative Analysis of the Brightness of Irregular and Semi-Regular Variable Stars.- 3/Type I (Classical) Cepheids.- A Preliminary Study of the Classical Cepheid P-L Relation in the R, I Photometric System.- A Photoelectric Investigation of the Double Cepheid CE Cas (Abstract).- Some Remarks on the Absolute Magnitudes of Cepheids.- On the Structure of the Cepheid Instability Strip (Review).- On the Presence of Variable Stars in Open Clusters (Abstract).- On Spectral Observations of ? Gem (Abstract).- 4/S Scuti Stars.- Stars of ? Scuti-type in Stellar Clusters (Review).- Physical Classification of Short-Period Variables.- Radial Pulsations of ? Sct Stars; Theory in Comparison with Observations.- The Mass and Evolutionary Status of AI Vel-Type Variables.- New Data on the ? Sct Star 44 Tau (Abstract).- 5/Wolf-Rayet Stars.- The Wolf-Rayet Stars (Review).- S Dor Type Variables in Other Galaxies (Review).- Observations of Radially Expanding Stratified Atmospheres of Wolf-Rayet Stars.- On the Chemical Composition of Wolf-Rayet Stars.- Spectroscopic Investigations on Luminous Emission-Line Objects (Abstract).- Variations of the Cm 5696 Å Emission Line in Wolf-Rayet Stars.- 6/Novae.- Novae (Review).- Towards a Realistic Model for Nova Envelopes.- On the Structure of the Envelope of Nova Del 1967 in the Nebular Stage.- Nova Del 1967: Radial Velocities and Excitation Potential of Lines.- Spectroscopic Observations of Nova Cep 1971.- 7/U Geminorum Stars.- U Geminorum-Type Stars (Review).- On the Origin of Nova-Like Binary Systems (Abstract).- VW Hydri, an U Geminorum-Type Star with Periodic Variations during Outbursts (Abstract).- Nonstationary Processes and Magnetic Field Generation in Binary Stellar Systems.- 8/Symbiotic Stars.- Symbiotic Stars (Review).- Physical Characteristics of V 1016 Cygni.- Photometric Properties of V 1329 Cygni.- Some Photometric Peculiarities of Symbiotic Stars (Abstract).- The Outburst of CI Cygni in 1973.- Spectroscopic Observations of Z Andromedae CI Cygni from 1968 to 1973.- Observations of the Peculiar Emission-Line Objects with Infrared Excess HD 45677, HD 87643 and GG Carinae.- Symbiosis in Radio Stars with Infrared Excess.- 9/Variable X-Ray Sources.- The Binary X-Ray Stars — the Observational Picture (Review).- The X-Ray Sources Sco X-l and Cyg X-2 as Binaries (Abstract).- Combined Optical and X-Ray Observations of Variable Stars.- The Identification and UBV Photometry of the Visible Component of the Cen X-3 Binary System (Abstract).- A Search for Super-Rapid Variability of X-Ray Sources and Other Peculiar Objects.- Circular Polarization of Cyg X-1, Sco X-1 and 3C 273.- Observations of Circular Polarization in V 1357 CYG=CYG X-1.- Discovery of Light Variability in the White Dwarf G 29–38.- Linear Polarization Observations of Some X-Ray Sources.- A Model for the Double System Containing the X-Ray Pulsar Her X-l.- The Crab Pulsar as a Component of a Binary System.- X-Ray Nova Flares.- 10/RR Lyrae and W Virginis Stars.- RR Lyrae- and W Virginis-Type Stars (Review).- Red Variables of the Halo and the Globular Clusters (Review).- General Properties of the Two Groups of Globular Clusters and their Variable Stars.- Period Changes of RR Lyrae Stars in Globular Clusters (Review).- Some RR Lyrae Variables with Blažko Effect (Abstract).- Spectra of Type II Cepheids (Abstract).- A Search for Rapid Variables and RR Lyrae Stars in the LMC on ESO Schmidt Plates.- On the Eclipsing Binaries in the Globular Clusters NGC 3201 and NGC 5139.- The Period-Luminosity Relation for Red Variables in Globular Clusters.- The Study of Light Curves with the Aid of Smoothing Spline-Functions.- 11/Variable Quasi-Stellar Objects and Nuclei of Galaxies.- Variable Quasi-Stellar Sources with Particular Emphasis on Objects of the BL Lac Type (Review).- Optical Variability of the Nuclei of Seyfert Galaxies (Review).- Variability of the Emission-Line Spectrum of the Nucleus of the Seyfert Galaxy NGC 7469.- Optical Variability of the N Galaxy 3C 371.