摘要:

AbstractFor the construction of more realistic models of magnetic stars the influence of large inhomogeneities in the distribution of line absorbing elements over the stellar surface on the determination of the mean longitudinal magnetic field component,Beff, is discussed. In this paper we assume the same magnetic field geometry as in paper I, i.e. the superposition of a dipole and an axissymmetrical quadrupole both lying in the equatorial plane with their axes parallel to one another. The models for the inhomogeneties can be classified by the concentration of the line absorbing elements:(1) at the polar caps, (2) in rings surrounding the polar caps, (3) in a belt in the neighbourhood of the “magnetic” latitude δ = 90°. The result of the computations shows that the amount of compensations of both polarities by integration over the visible hemisphere may be remarkably reduced, yielding values ofBeffnot so far away from the polar field strength as in the homogeneous models.Moreover, the large quadrupole contribution necessary in some cases to represent the observations in the homogeneous models may be considerably smaller with inhomogeneites taken into account. First comparisons between computed and observed values ofBeff(t) are made for the stars α2CVn, 53 Cam and HD

ISSN:0004-6337    

DOI:10.1002/asna.19793000102

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractFor a total of 60 infrared sources optical depths of the 10‐μm absorption band and temperatures of dust emitting the infrared radiation are given. Most sources have temperatures of 200–350 K, which is a consequence of observational selection. No relationship between optical depth of the 10‐μm band and temperatures wa

ISSN:0004-6337    

DOI:10.1002/asna.19793000103

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractPhotoelectric UBV observations of stars show the existence of an interstellar dust cloud of 0.2 mag. visual extinction and 1.5 pc diameter at 60°.5 galactic latitude. Properties of the cloud and the interstellar polarization in the region are being discussed

ISSN:0004-6337    

DOI:10.1002/asna.19793000104

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractSpectra of three high‐redshift quasars discovered on low‐dispersion objective prism plates were obtained. We present the emission line identifications and redshifts of the objects. Equivalent widths, line widths and low‐resolution line profiles are given characterizing the quasar emission region.The Lyα and CIV equivalent widths indicate that the considered quasars are luminous objects at high redshift. Both these equivalent widths are too low by a factor 4, whereas the N V/Lyα ratio is 5 times larger than predicted by the photoionisation models.The line profiles are compared with logarithmic, electron‐scattering and Gaussian profiles. In all the spectra rich absorption line systems ar

ISSN:0004-6337    

DOI:10.1002/asna.19793000105

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractFirst results of spectrographic observations of bright optical 5C1 and 5C2 radio candidates and of some blue radio‐quiet objects are presented. Among them are three emission line galaxies, three possible quasars and four galactic star

ISSN:0004-6337    

DOI:10.1002/asna.19793000106

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractFor a dynamo model obtained by idealizing features of the Sun, an analytic proof of the existence and a recursion formula for the determination of small time periodic solutions in a finite vicinity of the critical dynamo numbers are given. The nonlinear problem is solved by transforming the boundary value problem of the induction equation into a fixed point problem in an infinite dimensional sequence space and then applying the LYAPUNOV‐SCHMIDTmethod to reduce it to a relationship between dynamo number, amplitude and frequenc

ISSN:0004-6337    

DOI:10.1002/asna.19793000107

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

摘要:

AbstractOn the basis of photoelectric observations performed at the Teramo Observatory, theVlightcurve of Nova Cygni 1975 from August 1975 to July 1977 is given. Since three days after maximum thereafter, the decline pursued smoothly according the lawV= 2.5 + 3.9 lgt, and 680 days after maximum the star had weakened by 12.5 mag. The well‐known shortperiod light variation, which at the time of the early decline showed an amplitude smaller than 0.2 mag inVlight, on December 13, 1976, displayed an amplitude as high as 0.5 ma

ISSN:0004-6337    

DOI:10.1002/asna.19793000108

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY

ISSN:0004-6337    

DOI:10.1002/asna.19793000101

出版商:WILEY‐VCH Verlag    

年代:1979

数据来源: WILEY