scholarly journals A search for the modern counterparts of the Far Eastern guest stars 369 CE, 386 CE and 393 CE

2020 ◽  
Vol 497 (2) ◽  
pp. 1419-1433 ◽  
Author(s):  
Susanne M Hoffmann ◽  
Nikolaus Vogt
Keyword(s):  
Case Studies ◽  
Cataclysmic Variables ◽  
Fourth Century ◽  
Symbiotic Stars ◽  
Historical Texts ◽  
Naked Eye ◽  
Recurrent Nova ◽  
Nova Shell ◽  
Far Eastern ◽  
The Given

ABSTRACT In this study, we apply our previously developed method to investigate ancient transient sightings in order to derive consequences for modern astrophysical problems. We present case studies of three observations of so-called guest stars in the fourth century CE, which lasted several months each. These three observations had been discussed and suggested as possible supernovae, but slow novae are also viable alternatives. Our careful re-interpretation of the historical texts and the currently known objects in the given fields shed new light on this topic. In particular, for the two events in 386 and 393 CE we suggest possible supernova identifications, while in all three cases there are interesting candidates for past classical or recurrent nova eruptions among known cataclysmic variables (CVs) and/or symbiotic stars. We suggest that the transient of 369 can be explained as a classical and possibly recurrent nova instead of a supernova. The most plausible candidates are BZ Cam, a CV with a possible nova shell, or CQ Dra, a naked-eye multiple system perhaps able to permit an overwhelmingly bright nova with day-time visibility.

The Development of the Communication Skills of Individuals Living in Homes for People with Disabilities

2012 ◽  
Vol 2 (2) ◽  
pp. 56-70
Author(s):  
Petr Kopečný
Keyword(s):  
Czech Republic ◽  
Case Studies ◽  
Social Services ◽  
Communication Skills ◽  
Speech Therapy ◽  
People With Disabilities ◽  
Educational Support ◽  
The Czech Republic ◽  
The Subject ◽  
The Given

This paper concentrates on the area of special educational support provided to individuals living in homes for people with disabilities in the Czech Republic and presents partial research results illustrating the state of the provision of speech therapy to users of social services facilities falling under the jurisdiction of the Ministry of Labour and Social Affairs. The subject of the research is an analysis of support for the development of the communication skills of pupils living in social services facilities. The partial results of the research outline the approaches employed by the managerial staff of the given facilities in implementing special educational procedures, describe forms of speech therapy provision in homes for people with disabilities, and compare the attitudes of teachers and social services staff to the development of communication with the importance attributed to it by speech therapists and demonstrated by the case studies performed.

scholarly journals High Resolution Spectroscopy of Symbiotic Stars

1990 ◽  
Vol 122 ◽  
pp. 444-445
Author(s):  
Hugo E. Schwarz ◽  
Hilmar W. Duerbeck ◽  
Waltraut C. Seitter
Keyword(s):  
High Resolution ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
High Resolution Spectroscopy ◽  
Symbiotic Stars ◽  
Current Interest ◽  
Echelle Spectrograph ◽  
La Palma ◽  
Recurrent Nova ◽  
The Uk

A high resolution spectroscopy survey of symbiotic stars is conducted in the southern hemisphere by the authors, using the Coudé Echelle Spectrograph (CES), equipped with a CCD at the ESO Coudé Auxiliary Telescope (CAT), and concurrently in the northern hemisphere by Bode, Evans, Meaburn and collaborators, using the UK facilities at La Palma. So far, more than 400 spectra of about 70 stars have been obtained, mostly during 1988 and 1989. The southern part of the work will be described below.The discussion of symbiotic stars in the context of novae is not far-fetched. A number of symbiotics are known to have nova-like outbursts, and several novae are not easily distinguished from symbiotic stars. A noteworthy example is the most recently recognized recurrent nova, V745 Sco, first observed by Liller on July 24, 1989. It is described here, both because in late decline it represents a link between novae and symbiotic stars, and because of its current interest.

scholarly journals The evolutionary status of symbiotic stars

1982 ◽  
Vol 70 ◽  
pp. 275-282 ◽  
Author(s):  
Bronislaw Rudak
Keyword(s):  
Cataclysmic Variables ◽  
Evolutionary Status ◽  
Spherically Symmetric ◽  
Symbiotic Stars ◽  
Transfer Phase ◽  
Common Envelope ◽  
Long Period ◽  
Red Giant ◽  
Detached Binaries ◽  
Rapid Mass

AbstractThe evolutionary relations between symbiotic stars and cataclysmic variables are presented. The symbiotic stars are assumed to be long period detached binaries containing a carbon-oxygen degenerate primary and a red giant losing its mass through a spherically symmetric wind. Such systems can be obtained in Case C evolution, provided a common envelope during a rapid mass transfer phase was not formed. The same way recurrent novae containing a red giant as a secondary component may be produced. The factors influencing the differences between symbiotic stars and nova-type stars are discussed.

scholarly journals Family links between Planetary Nebulae nuclei and cataclysmic variables, binary white dwarfs, R CrB stars, and SNe IA

1997 ◽  
Vol 180 ◽  
pp. 85-90
Author(s):  
L.R. Yungelson ◽  
A.V. Tutukov
Keyword(s):  
White Dwarfs ◽  
Cataclysmic Variables ◽  
Planetary Nebulae ◽  
Close Binaries ◽  
Symbiotic Stars

We analyse the population of PNe and links between binary PNNi and stars which are in the later evolutionary stages. In a model which assumes that all stars are born in binaries, about 16% of PN result from ejection of common envelopes in close binaries, 85% of single PNNi are formed by merger of components of binaries. In the model, 5% of PNNi may be precataclysmic binaries, 5% may be precursors of symbiotic stars, 0.4% may be pre-SN Ia, 0.1% - precursors of hydrogen-deficient giants. About 0.1% of all PNe may be hydrogen-deficient.

scholarly journals Cataclysmic variables as possible counterparts of ancient Far Eastern guest stars

2020 ◽  
Vol 494 (4) ◽  
pp. 5775-5786 ◽  
Author(s):  
Susanne M Hoffmann ◽  
Nikolaus Vogt
Keyword(s):  
Cataclysmic Variables ◽  
Supplementary Information ◽  
Future Research ◽  
Historical Events ◽  
Significant Excess ◽  
Classical Novae ◽  
Classical Nova ◽  
Intermediate Polars ◽  
Far Eastern

ABSTRACT Continuing our efforts to select possible classical nova candidates among Far Eastern guest stars and to identify them with modern cataclysmic variables (CVs), we present a search for counterparts in 24 promising areas of the sky corresponding to ancient observations between 204 bce and 1690 ce. These areas were derived by us in a previous paper. Based on the physical entities of the CVs in our areas and reasonable magnitude limits compatible with the distribution of known eruption amplitudes of telescopic classical novae, we present a catalogue of a total of 80 CVs and related targets that could possibly have caused the historical sightings. This list could potentially be reduced by additionally discussing further information such as brightness or duration. In some cases, we present a detailed discussion of the interpretation of ancient sources comparing them with properties of the brightest CVs in the field. In order to estimate whether this list is representative, we discuss the distribution of CV types in our catalogue of counterparts for the historical events. Compared to the entire sky, the surface densities of most CV subtypes in our search fields reveal similar values, except for polars and intermediate polars, i.e. strongly magnetic CVs, for which a significant excess in our search fields was detected. Finally, we give an outlook towards future research in this topic, and provide in the online supplementary information a complete atlas of the celestial maps of all 24 guest star events, displaying the search areas and locations of CVs within them.

scholarly journals X-Ray Observations of Cataclysmic Variables

1987 ◽  
Vol 93 ◽  
pp. 207-223
Author(s):  
J.P. Osborne
Keyword(s):  
Light Curve ◽  
Spectral Range ◽  
Cataclysmic Variables ◽  
High Sensitivity ◽  
Light Curves ◽  
X Ray ◽  
Broad Spectral Range ◽  
Intermediate Polars ◽  
Recurrent Nova

AbstractThe X-ray observatory EXOSAT spent over 1000 hours observing cataclysmic variables. Some of the major results reviewed here are: soft X-ray light curve changes in AM Her objects, orbital effects in the X-ray light curves of intermediate polars and U Gem, regular behaviour in the inter-outburst X-ray flux of VW Hyi, and X-ray emission from the tenuous remnant of the recent recurrent nova RS Oph. The ability of EXOSAT to make long uninterupted observations at high sensitivity over a broad spectral range and to react quickly to cosmic events has yielded a dataset of a quality that will not be surpassed for many years.

Flowrate formulation and displacement analyses for deviation function-based gerotor pumps

2010 ◽  
Vol 225 (2) ◽  
pp. 480-487 ◽  
Author(s):  
D C H Yang ◽  
J Yan ◽  
S-H Tong
Keyword(s):  
Case Studies ◽  
Deviation Function ◽  
Dimensionless Parameters ◽  
Displacement Analysis ◽  
Gerotor Pumps ◽  
Deviation Functions ◽  
The Given ◽  
Circular Pitch

This article presents a research on the flowrate formulation and displacement analysis of gerotor pumps. The flowrate formula is based on the deviation function and is applicable to gerotors with any pitch curves and generating curves that are either circular or non-circular. For gerotors with the circular pitch curves and generating curves, the derivation of the formula proposed here is much simpler than the current available one. Two dimensionless parameters, the lobe non-circularity and the pitch non-circularity, are then introduced so that gerotor performance can be analysed systematically. As examples, the specific flowrate and displacement curves with the combinations of sinusoidal and polynomial pitch curves and deviation functions are illustrated. Based on these case studies, it is found that in general the specific displacement increases according to the lobe non-circularity, whereas the pitch non-circularity has only the minimum effects on the performance of pumping displacement. The results of the given case studies also show that the pumps with less lobe numbers are capable to have relatively larger specific displacements.

scholarly journals Coin Alloys of Tauric Chersonese in the Period of Independence

2021 ◽  
pp. 374-401
Author(s):  
Tatiana N. Smekalova ◽  
Natalia L. Demidenko ◽  
Andrey N. Gavriluk
Keyword(s):  
Fluorescence Analysis ◽  
Fourth Century ◽  
The State ◽  
Second Century ◽  
Low Grade ◽  
Wine Production ◽  
Territorial Expansion ◽  
The North ◽  
The Given ◽  
First Time

This paper presents the results of X-ray fluorescence analysis of the composition of alloys of the two largest collections of coins of ancient Chersonese residing in the State Historical and Archaeological Museum Preserve of Tauric Chersonese and the Yevpatoria Regional Museum. In total, about a thousand coins studied, which, together with the 400 coins previously examined from the State Hermitage Museum, constitutes a solid basis for conclusions. The given paper analyses the data obtained for coins of Chersonese in the Period of Independence, that is from the emergence of local coinage in the early fourth century BC to the wars of Diophantos in the late second century BC. For the first time it has been determined that big dichalkoi were minted from a special coin alloy, two-component high-tin bronze, in the period of economic prosperity of Chersonese in the second half of the fourth and third centuries BC. These coins served as the financial basis for important transformations in the near and distant chora: the land division system of vineyards and territorial expansion of Chersonese into the north-western Taurica. Only in the third century BC, in the period of an unprecedented consolidation of land properties and the transformation of the wine production into a commodity industry, the minting of large silver coins of full metal value began probably for big financial deals and payments in international trade. The crisis in the minting of Chersonese in the late second century BC touched silver drachmae, the overwhelming majority of which were minted from a low-grade silver alloy with the copper comprising more than a third of the composition. Thus, full-weight coins turned to conditional money.

scholarly journals Lipid­carbohydrate metabolism and nutrition in the indigenous and non­indigenous population of the north-east of Russia.

2018 ◽  
Vol 96 (6) ◽  
pp. 544-551
Author(s):  
I. V. Averyanova ◽  
A. L. Maksimov
Keyword(s):  
Fat Metabolism ◽  
Young Male ◽  
Blood Lipid ◽  
Capillary Blood ◽  
North East ◽  
The North ◽  
Age Cohort ◽  
Academy Of Sciences ◽  
Far Eastern ◽  
The Given

Scientific-research center «Arktika» far-eastern branch of the Russian academy of sciences, 685000, Magadan, Russia Young male residents ofMagadan region and Chukotsky Autonomous District aged 17-21, all are representatives of Russia’s northeast ethnic peoples were examined in comparison with Caucasoid subjects born in the north in the p>-2 generation to study the blood lipid and glucose values as well as the dietary structure. In order to ascertain the subjects ’ lipid and carbohydrate basic values, the CardioChek PA biochemical express-analyzer (USA) was used during the study of the capillary blood samples taken from the examinees on empty stomach, 10-12 hours after the last meal. Besides, the program set of “ASPON-nutrition” was used to analyze the subjects ’ daily diets for assessing their dietary structures and nutrition facts. All the examined subjects demonstrated the similar changes in lipid-carbohydrate profile resulted in low fat metabolism and high glucose close to the upper limit of physiological norm. Reliable ethnic and region-related peculiarities in the studied metabolic parameters were found. Of note, that Aboriginal subjects were the highest in the blood glucose. They showed higher values ofLPHD and lower values ofLPLD compared to those of Caucasoid subjects. Significant nutrition irrationalities such as imbalance in macronutrients and energetic deficiency were found. The observed diets contain excess carbohydrates and insufficient protein and fat saturation at lowered daily energetic value for the given age cohort.

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