Non-periodic phenomena in variable stars : 4th Colloquium on Variable Stars, held in Budapest, Hungary, 5-9 September 1968

Front Matter....Pages I-XII Front Matter....Pages 1-1 Statistical and Physical Interpretation of Non-Periodic Phenomena in Variable Stars....Pages 3-19 Spectral Analysis of the Light Curves of T Tauri Stars and Other Objects....Pages 21-39 On the Presumed Pre Supernova Stage for Type II Super-Novae....Pages 41-49 Synchronous Three Colour Stellar Photometry at the Catania Astrophysical Observatory....Pages 51-56 About the T. V. Photometry of Faint Variable Stars....Pages 57-58 Front Matter....Pages 59-59 Extremely Young Stars....Pages 61-73 The Light Variations of the Nuclei in Herbig-Haro Object No. 2, 1946–1968....Pages 75-83 Photoelectric Observations of 6 Southern RW Aurigae Variables....Pages 85-92 Hydrogen Emission Phenomena in T Tauri Stars....Pages 93-101 The Evidence for Variable Infall of Material in the Ultraviolet Excess Stars....Pages 103-105 Emission Hα-Line Profiles in Several T Tau Stars....Pages 107-109 Flares of UV Ceti Type Stars....Pages 111-126 Cooperative 24-Hour Observations of UV Ceti-Type Stars....Pages 127-130 The Classification of Photometric Light-Curves of Flares of UV Ceti Stars....Pages 131-136 Multi-Colour Photometry of Orion Flare Stars....Pages 137-148 Photoelectric Research on Flare Stars at the Catania Astrophysical Observatory....Pages 149-157 HD 160202 — An Early-Type Flare Star....Pages 159-160 On the Group of Young Stars in the Solar Vicinity....Pages 161-163 Flare Stars Near NGC 7023....Pages 165-167 On the Polarimetric Study of UV Ceti Type Star Flares....Pages 169-171 Front Matter....Pages 59-59 The Problem of Irregular Variations in Magnetic Stars....Pages 227-237 Photometric Search for Periodicity Among Magnetic Stars....Pages 239-241 Photometric Research on Magnetic Stars at the Catania Astrophysical Observatory....Pages 243-251 RY SGR during the 1967–8 Minimum: A Blue Continuum and Other Spectroscopic and Photometric Observations....Pages 253-256 Spectroscopic Observations of the Recurrent Nova RS Ophiuchi from 1959 to 1968....Pages 257-260 Spectroscopic Observations of the Recurrent Nova T Pyxidis during the 1967 Maximum....Pages 261-269 Preliminary Report on the Spectrum of Nova Vul 1968....Pages 271-276 On Nova Delphini 1967 and Some Slow Nova Characteristics....Pages 277-284 Preliminary Results of a Survey of Nebular Variables and Flare Stars....Pages 173-177 Of and be Stars....Pages 179-189 Photoelectric Observation of Line Profiles with High Time Resolution in B and Be Stars....Pages 191-196 Some Remarks on the Spectral and Light Variability of P Cygni....Pages 197-201 Spectral Variations of P Cygni....Pages 203-213 Variations in the Continuous Spectrum of γ Cas....Pages 215-221 Variations Rapide, Probablement Non Périodiques d’Enveloppes d’Étoiles Be....Pages 223-226 Front Matter....Pages 285-285 Tidal Resonances in Some Pulsation Modes of the Beta Canis Majoris Star 16 Lacertae....Pages 287-296 Variations Dans Le Spectre De γ Pegasi....Pages 297-301 Is γ Bootis a Spectrum Variable Star?....Pages 303-306 The Short-Period Variability of 14 Aur (HR 1706)....Pages 306-311 On The Nature of Some of the O-C Diagrams of the Rr Lyrae Variables in M5....Pages 313-320 Front Matter....Pages 285-285 Instability of Light Curves and Periods of Longperiod Cepheids Belonging to the Spherical Component of the Galaxy....Pages 321-324 Correlations Between the Irregularities of the Period and Radial Velocity, Length of Period, Amplitude and Spectrum of Mira-Variables....Pages 325-329 The Irregularities in the Light-Changes of Mira Ceti....Pages 331-338 On the Intrinsic Light-Polarization in-Some Late Type Stars....Pages 339-341 Front Matter....Pages 343-343 Introductory Report....Pages 345-354 Photometric Observations of the Peculiar Blue Variable TT ARI = BD + 14°341....Pages 355-359 Photometric Effects for Highly Distorted White Dwarf Secondaries in Close Binary Systems....Pages 361-369 Photometric Observations of Nova WZ Sagittae and their Interpretation....Pages 371-376 Eclipses of U Geminorum....Pages 377-380 The Standstills of Light of Z Cam Stars Photoelectric and Spectrographic Observations....Pages 381-382 Analyse des Courbes de Lumière des Étoiles du Type U Geminorum....Pages 383-390 On a Possible Cause of Brightness Fluctuations in Close Binary Systems of Dwarf Stars....Pages 391-393 Symbiotic Stars....Pages 395-410 Spectral Evolution of the Peculiar Star Mhα 328-116 (V 1016 CYG) from 1965 to 1967....Pages 411-413 Spectroscopic Variations in WY Gem, W Cep and HD 4174....Pages 415-418 Theoretical Light Changes of W Uma Stars with Low Mass Ratio....Pages 419-422 On the Reflection Effect in Close Binaries....Pages 423-426 Nearly Contact Binary HD 17514....Pages 427-427 Non- Periodic Phenomena in Binary Systems. Conventional Binaries....Pages 429-433 Photometric Research on RS CVn at the Catania Astrophysical Observatory....Pages 435-441 Front Matter....Pages 343-343 Changes in the Light Curve of Beta Lyrae 1958–1959....Pages 443-455 The O’Connell Effect in Some Eclipsing Variables....Pages 457-464 Sudden Changes in the Period of Algol....Pages 465-470 On the Research Program Concerning Eclipsing Variables at the Observatories Nürnberg and Izmir....Pages 471-472 Front Matter....Pages 473-473 The Third Catalogue of Variable Stars in Globular Clusters....Pages 475-479 The Cepheids on the Colour-Colour Plot....Pages 481-484 Irregular Variations of Radio Sources....Pages 485-490 From September 5 until September 9, 1968, the IVth Colloquium on Variable Stars was held in Budapest, Hungary. The Colloquium was organized by a committee consisting of G.H. Herbig (President), A. Boyarchuk, M.W. Feast, D. McNamara, J.E. Merrill, D.J.K. O'Connell, V. Tsessevich, W. Wenzel. The local organization was placed in the hands of a Committee consist ing of members of the Konkoly Observatory, Budapest: L. Detre (Chairman), 1. Almar, Julia Balazs-Detre, K. Barlai, M. Ill, S. Kany6, M. Lovas and of J. Kovacs (Hungarian Academy of Sciences). The Colloquium was attended by about 90 scientists representing Argentina, Austria, Bulgaria, Canada, France, GDR, GFR, Hungary, Italy, The Netherlands, Poland, Roumania, South Africa, Sweden, United Kingdom, U.S.A., U.S.S.R. As chairmen acted at the sessions: M.W. Feast, G.H. Herbig, J. Sahade, A. Boyarchuk, W. Wenzel, F.B. Wood and L. Rosino. The contents of the present volume parallel closely the programme of the individual sessions of the Colloquium