The outbursts of cometary brightness háve been attracting the astronomers attention for more than a hundred of years. They play a significant role in the study of physical nature and evolution of comets. An outstanding Soviet astronomer S.K. Vsekhsvyatsky (i)
pointed out the corpuscular fluxes as a plausible factor being responsible for the variation of cometary brightness. He was the
first to suggest that the effect of fragmentation of solar corpuscular fluxes on cometary ices is one of the causes generating the
brightness outbursts.
In this paper, two different analytical techniques for solving visual double star orbis with inclination equal to 90° are given. The first is based on Docobo´s method, and the second is derived by using the Fourier Transform for angular distances. Both techniques are applied to the pairs 1919252442 and 1933882339.
The evolutionary ayntheaio rnethod is applied to calculate Mgl+MgH λ 5150 and TiO λ 7150 absorption features of integrated spectra and integrated UBV colours of a stellar system. These calculations are used to investigate star formation rate in nuclei of some spiral galaxies. The (IMg, B-V) diagram is shown to be a goo discriminator between metallicity and star formation effects. Star formation rates, metallicities and initial mass function slopes are obtained for the nuclei of 8 spiral galaxies. Star formation rates in nuclei correlate with rotation velocities of galaxies. Dynamical friction of gas clouds system in a galactic stellar disk is the possible cause of that correlation.
This paper deals with the determination of global star formation rates (SPRs) from radlo free-free and submm/FIR dust emission. Masslve, hot and luminous stars interact with the surrounding
interstellar matter (ISM) lonlzing the gas and heating the dust. O star formation rates (OSFR) in the galactic disk are estimated with observed Lyman continuum photon production rates. Extrapolation to lower mass stars with a constant inltial mass function (IMF) yields, however, too high total SFRs. Furthermore, the lock-up rate, i.e. the rate at whlch gas transformed into stars is permanently locked up in low mass and dead stars, can not reproduce the present-day mass distribution of the galactic disk. Agreement between Lyc photon production rate and time integrated lockup rate can be reached by introducing bimodal star formation in the galactic disk. Thls means that induced star formation in main spiral arms produces only masslve stars ≥3mq. while spontaneous star formation in the interarm region produces stars in the total mass range ≥0.1 mq.
Estimates of SFR based on Lyc photon production rates can not easily be applied to external galaxies because of the difficulty to separate radio synchroton and free-free emission. It is found that slmilar problems are encountered in separating the emission from warm dust (heated by OB stars) and cold dust (heated by the general Interstellar radiation field). The relation between IR luminoslťy and star formation actlvity of galaxies is much more complex than previously assumed.
I briefly summarise and give a critique of the work discussed here on the following major topics that were presented at the rate of one per day: bipolar flows and their associated masers and Herbig-Haro objects; the initial mass function; the large scale gas and kinematical distribution; star clusters; and star formation and starbursts. The dynamics reviews given after my summary promised to be most interesting but are not included here owing to the constraints of causality.
Structural peculiarities of most open star clusters have been studied. They could indicate dynamical influences and disruption of clusters. The distribution of the number of disturbed clusters relatively to the total number of clusters seems to suggest some connection with the distribution of the interstellar matter in the sky.