The 10.7 GHz observation of four Virgo cluster spirals made with the 100 m MPIfH radio telescope are examined for possible effects of the cluster environment. Their radio structure parameters were compared to these known from observations of nearby field spirals. A search for an anomalous composition of the 10.7 GHz radiation and for a general deficiency of these spirals relative to field galaxies has been also made.
The distribution of stars of mag. 7-0 and brighter of the H. D. C. is here studied in the system of galatic co-ordinates. There are tables of numbers of stars according to both the co-ordinates for individual clases of magnitude and for all the spectral subdivisions. Also the distribution of the density of stars in longitude and latitude separately is studied for the spectral classes B, A, F, G, K, M. Finally to illustrate the distribution of stellar density according to both co-ordinates simultaneously, the maps for the classes B, A, F, G, K, M were constructed with the lines of the same density. and Text je doplněn 5 grafy hustoty hvězd (nestránkováno)
Radial velocity variations of the K supergiant Xi Cygnl are Investlgated on the basis of publlshed as well as new values from spectrograms In the visual and near infrared region obtalned In the period of 1977-1984 at Ondřejov, Shemakha, and Crlmea observatories. A circular orbit (P = 113.3873 days, Tmax = 2430214.33 HJD, K1 = 3,47 km/s, Vo = -20.0 km/s), still preliminary. confirms the period derlved by Parsons (1983). More accurate data are needed and the problem of the long period (Reimers 1981)
should be investigated.
The visual observations of the soviet artificial satellites made in ČSR or by czechoslovak observers during the IGY (to the end of 1958) are collected. AU these data were sent to the IGY regional centre at Moscow. The list of the observing stations is added, too. and Edited by V. Guth and L. Sehnal
We introduce a new method of solution of the light curves of eclipsing binaries based on the Wilson and Devinney ((1971) Roche model. We performed an interesting application of the procedure to the binary system TT Her.
A systematic study of the ultraviolet spectra of the Algol-like semidetached binary stars is described. Revision of the traditionally accepted spectral types has been found necessary in most cases toward earlier spectral types. Superionized emission lines seen at total eclipses show interesting differences in intensities.