[en] On the basis of a uniform series of photographic observations a 163 day period for the light variations of the N galaxy 3C 371 is found. The similarity of the form of the light curve for the different components of the light variations with the different time scales is noted. The form of the light variations was observed to be identical to that of the quasars 3C 345 and 3C 454.3. (Auth.)

[en] Slow and rapid fluctuations of emission and absorption features of the C III emission line at lambda5696 A in WC stars are described. They might be attributed to moving clouds in the expanding stellar envelope. (Auth.)

[en] Spectroscopic data in the visual region is described for the peculiar emission-line objects with IR-excess HD 45677, HD 87643, and GG Car. A model consisting of a central star surrounded by an equatorial disc and a dust shell is suggested. (Auth.)

[en] It is widely accepted that pulsating variables with periods less than 0.2 day fall into two distinct groups: RR type stars and delta Scuti type stars. The physical properties of these groups are examined to see whether any clear-cut difference can be found. It is suggested that the two groups are fundamentally similar: hydrogen shell burning stars of about two solar masses. The only difference is the mode of pulsation. (P.J.S.)

[en] Four years ago the author examined the flare incidence data then available for UV Ceti and V1054 Oph (Wolf 630) and concluded that no evidence could be found for periodic or secular variation in the levels of activity. The situation for both stars has changed since then. About 120 ultraviolet flares of V1054 Oph have been reported by MacConnell (1968) and Kunkel (1973). Levels of activity for five epochs have been calculated and plotted. The mean activity is at U₀=14.12+-0.13. The variance is about double that expected for activity at a constant level, and the figure suggests a weak periodic variation between one and two years. (Auth.)

[en] An introduction to the use of autocorrelative analyses in the case of irregular and semi-regular brightness variations is given. This method can be used for division of purely stochastic and unrandom perturbed component processes, and for determination of types of processes which modulate the process of variability. (Auth.)

[en] The light variation in V,B-V,U-B is shown and the change in the Hα,Hβ emission-line profiles is described. (Auth.)

[en] The paper contains preliminary results of theoretical investigations of the light curves of RCB variables. A circumstellar dust envelope is assumed to be the source of the great visual opacity as well as the infrared and violet excesses. The processes of grain formation and the interaction with the radiation field are discussed briefly. The results of a laboratory experiment concerning the problem of the violet continuum are also described. (Auth.)

[en] A rediscussion of the period-luminosity relation of type I-cepheids is presented. Special attention is paid to the radius and its variation. (Auth.)

[en] Spectroscopic observations of Nova Cep 1971 in the visual and infrared regions were carried out at Asiago from July to December 1971. The spectra were characterized at first by the presence of wide emission bands of moderate excitation (H, OI, NI, FeII) accompanied by two absorption systems with mean radial velocity -1300 km s^-1 and -2200 km s^-1. The velocity was increasing with time. The absorption spectrum disappeared in September and soon the nova entered the nebular stage. The HeI flash was observed in mid-September. In the following months the degree of excitation was steadily increasing. The nebular [OIII] lines became outstanding, even stronger than Hα and the spectrum was characterized by forbidden and permitted lines of relatively high ionization potential (OII, OIII, NII, NIII, HeII). The profiles of the emission bands were complex from the beginning, with a strong central peak. Later, most of the bands split into two separate components, with radial velocities = +- 1360 kms^-1. The light curve was that of a relatively fast nova. The minimum, B approximately 17.5, was attained in the first half of 1973. (Auth.)