{"title":"Solar spectral observations at the Ondrejov Observatory with Moscow State University cooperation","authors":"P. Kotrč, E. Kononovich, Y. Kupryakov","doi":"10.1080/10556790701415328","DOIUrl":"https://doi.org/10.1080/10556790701415328","url":null,"abstract":"On the occasion of the 175-year anniversary of the Moscow State University Sternberg Astronomical Institute we would like to outline the history and some results obtained by the Institute in cooperation with the Ondřejov Astronomical Institute of the Czech Republic Academy of Sciences. The development and current state of this cooperation and the mutual solar observation results are presented. At the end of the 20th century, by a special international contract between the two institutes, one of the five Carl Zeiss new solar instruments, namely the ‘Horizontal Sonnen Forschungs Anlage’ (HSFA) was installed at the High-altitude Sternberg Institute Observatory near Alma-Ata. In the 1980s four other instruments were mounted in Czechoslovakia (two of them in Ondřejov and the other two in Stara Lesna and Hurbanovo). Both Ondřejov instruments (HSFA 1 and 2) were modernized over the period in the 2000–2004, mainly to improve their electronic control systems. A new spectral grating, corresponding optics and detect...","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"42 1","pages":"267-273"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91226870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A certain cosmological solution and search for possibly related astronomical objects","authors":"S. Bereznitsky, D. Tsvetkov","doi":"10.1080/10556790701524384","DOIUrl":"https://doi.org/10.1080/10556790701524384","url":null,"abstract":"Certain cosmological solution to the equations of the general theory of relativity is considered. It is shown that we may expect concentration of matter along lines representing singularities of the solution. Evidence for possible related astronomical objects is presented.","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"62 3","pages":"285-288"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/10556790701524384","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72466569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. Breus, I. Andronov, S. Kolesnikov, N. M. Shakhovskoy
{"title":"Simultaneous linear and circular polarimetry of variable stars in the 2.6 m Shain telescope computer program for data reduction","authors":"V. Breus, I. Andronov, S. Kolesnikov, N. M. Shakhovskoy","doi":"10.1080/10556790701243225","DOIUrl":"https://doi.org/10.1080/10556790701243225","url":null,"abstract":"The new computer program PolarObs-2006 is described, which allows us to reduce the observations obtained with the 2.6 m Shain (ZTSh) telescope which is equipped with a new photometer–polarimeter. The program is used to investigate variable stars of different types.","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"5 1","pages":"241-243"},"PeriodicalIF":0.0,"publicationDate":"2007-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81407697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Bignall, D. Jauncey, J. Lovell, A. Tzioumis, J. Macquart, L. Kedziora-Chudczer
{"title":"Observations of intrahour variable quasars: scattering in our Galactic neighbourhood","authors":"H. Bignall, D. Jauncey, J. Lovell, A. Tzioumis, J. Macquart, L. Kedziora-Chudczer","doi":"10.1080/10556790701596804","DOIUrl":"https://doi.org/10.1080/10556790701596804","url":null,"abstract":"Abstract Interstellar scintillation (ISS) has been established as the cause of the random variations seen at centimetre wavelengths in many compact radio sources on timescales of a day or less. Observations of ISS can be used to probe structure both in the ionized insterstellar medium of the Galaxy and in the extragalactic sources themselves down to μ as scales. A few quasars have been found to show large amplitude scintillations on unusually rapid, intrahour timescales. This has been shown to be due to weak scattering in very local Galactic ‘screens’, within a few tens of parsec of the Sun. The short variability timescales allow detailed study of the scintillation properties in relatively short observation periods with compact interferometric arrays. The three best-studied ‘intrahour variable’ quasars, PKS 0405−385, J1819+3845 and PKS 1257−326, have been instrumental in establishing ISS as the principal cause of intraday variability at centimetre wavelengths. Here we review the relevant results from obse...","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"31 1","pages":"567-573"},"PeriodicalIF":0.0,"publicationDate":"2007-09-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84656368","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Highly evolved close binary systems","authors":"A. Cherepashchuk","doi":"10.1080/10556790701295175","DOIUrl":"https://doi.org/10.1080/10556790701295175","url":null,"abstract":"The basic properties of highly evolved close binary systems are described. In these systems the first mass exchange between the components is completed and peculiar objects are formed: Wolf–Rayet stars, white dwarfs, neutron stars and black holes. The observational characteristics of these systems are in agreement with the modern theory of evolution of close binary systems. Investigation of these systems is very important for astrophysics and fundamental physics. In particular, 20 black-hole candidates of stellar masses have been discovered up to now in highly evolved close binaries. A catalogue of highly evolved close binary stars is described as well as its new electronic version, work on which is in progress at the Sternberg Astronomical Institute.","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"13 1","pages":"35-45"},"PeriodicalIF":0.0,"publicationDate":"2007-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87121149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Rovithis-Livaniou, S. Tsantilas, A. Kalimeris, P. Rovithis, I. Voloshina
{"title":"Latest results on the period behaviour of the contact binary AB And","authors":"H. Rovithis-Livaniou, S. Tsantilas, A. Kalimeris, P. Rovithis, I. Voloshina","doi":"10.1080/10556790701323035","DOIUrl":"https://doi.org/10.1080/10556790701323035","url":null,"abstract":"The O−C diagram of the contact eclipsing binary AB And was reanalysed, using data obtained up to now. It was thus found that the real period variations, presented by the P(E)−P e function, have changed; both P mod and its amplitude continue to decrease. Moreover, assuming that the observed orbital period changes of AB And are due only to magnetic activity, the variation in the magnetic field and also P mod were calculated. As their variability was found to be less than that of other examined cases, this is connected to the O−C diagram shape of AB And.","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"137 1","pages":"117-120"},"PeriodicalIF":0.0,"publicationDate":"2007-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86650258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"X-ray properties of early-type binaries: theory versus observations","authors":"I. Antokhin","doi":"10.1080/10556790701295134","DOIUrl":"https://doi.org/10.1080/10556790701295134","url":null,"abstract":"Early-type binary stars are expected to be more luminous and hard X-ray sources than single stars are. However, recent observational studies show that, on average, the X-ray properties of single and binary early-type stars are not very different. We review these studies and discuss a possible explanation for this discrepancy.","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"28 1","pages":"59-62"},"PeriodicalIF":0.0,"publicationDate":"2007-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81492133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Observational evidence of interacting processes in the system TW Draconis","authors":"M. Zejda, Z. Mikulášek","doi":"10.1080/10556790701312657","DOIUrl":"https://doi.org/10.1080/10556790701312657","url":null,"abstract":"TW Draconis is one of the best studied Algol-type eclipsing binaries. There is significant evidence for miscellaneous interacting physical processes between binary components and these are manifested in period and light curve changes. We studied these processes on the basis of a long-time series of photometric and spectroscopic observations.","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"46 1","pages":"125-128"},"PeriodicalIF":0.0,"publicationDate":"2007-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79062259","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Apsidal motion in eclipsing binary systems","authors":"K. Khaliullin","doi":"10.1080/10556790701323092","DOIUrl":"https://doi.org/10.1080/10556790701323092","url":null,"abstract":"A review of work devoted to the problem of apsidal motion in eclipsing binary systems (EBSs) is given. It is shown that recent theoretical models for stars in the main sequence in general are in agreement with the observed apsidal motion velocities. However, the stars of types I–III show more central condensation than predicted by the theoretical models. It is revealed that the observed rates of the stellar photospheric rotation poorly reflect the real rates of axial rotation of greater part of stellar mass (core) and that cores of components of the EBS rotate, on average, more rapidly than their photospheres.","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"24 1","pages":"13-21"},"PeriodicalIF":0.0,"publicationDate":"2007-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82212579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. I. Kumsiashvili, R. Natsvlishvili, N. Kochiashvili
{"title":"A new unique phenomenon for the RY Scuti binary star","authors":"M. I. Kumsiashvili, R. Natsvlishvili, N. Kochiashvili","doi":"10.1080/10556790701300546","DOIUrl":"https://doi.org/10.1080/10556790701300546","url":null,"abstract":"We present the results of reanalysis of old electrophotometric data on RY Scuti obtained at the Abastumani Astrophysical Observatory, Georgia, during 1972–1990 and at the Maidanak Observatory, Uzbekistan, during 1979–1991. Unstable processes in RY Sct from period to period, from month to month and from year to year are revealed. The magnitude of this variation is from hundredths to tenths. Furthermore, periodic changes in the system's light are displayed near the first maximum on timescales of a few years. This is of great interest with regard to some similar variations seen in luminous blue variable stars and, in particular, in S Dor-type stars. This also could be closely related to the question of why RY Sct ejected its nebula.","PeriodicalId":52135,"journal":{"name":"Astronomical and Astrophysical Transactions","volume":"17 1","pages":"103-110"},"PeriodicalIF":0.0,"publicationDate":"2007-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78192186","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}