scholarly journals Counterparts of Far Eastern Guest Stars: Novae, supernovae, or something else?

2020 ◽  
Vol 496 (4) ◽  
pp. 4488-4506 ◽  
Author(s):  
Susanne M Hoffmann ◽  
Nikolaus Vogt
Keyword(s):  
Supernova Remnants ◽  
Modern Science ◽  
Test Sample ◽  
Classical Novae ◽  
Cataclysmic Binaries ◽  
Classical Nova ◽  
Transient Events ◽  
Recurrent Nova ◽  
Far Eastern

ABSTRACT Historical observations of transients are crucial for studies of their long-term evolution. This paper forms part of a series of papers in which we develop methods for the analysis of ancient data of transient events and their usability in modern science. Prior research on this subject by other authors has focused on looking for historical supernovae and our earlier work focused on cataclysmic binaries as classical novae. In this study we consider planetary nebulae, symbiotic stars, supernova remnants, and pulsars in the search fields of our test sample. We present the possibilities for these object types to flare up visually, give a global overview on their distribution, and discuss the objects in our search fields individually. To summarize our results, we provide a table of the most likely identifications of the historical sightings in our test sample and outline our method in order to apply it to further historical records in future works. Highlights of our results include a re-interpretation of two separate sightings as one supernova observation from May 667 to June 668 CE, the remnant of which could possibly be SNR G160.9+02.6. We also suggest the recurrent nova U Sco as a candidate for the appearance observed between Scorpius and Ophiuchus in 891, which could point towards a long-term variability of eruption amplitudes. In addition, we find that the ‘shiny bright’ sighting in 1431 can be linked to the symbiotic binary KT Eri, which erupted as a naked eye classical nova in 2009.

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 A pre-outburst signal in the long-term optical light curve of the recurrent nova RS Ophiuchi

2011 ◽  
Vol 414 (3) ◽  
pp. 2195-2203 ◽  
Author(s):  
S. Adamakis ◽  
S. P. S. Eyres ◽  
A. Sarkar ◽  
R. W. Walsh
Keyword(s):  
Light Curve ◽  
Optical Light Curve ◽  
Recurrent Nova

Promoting astronomy in developing countries: an historical perspective

2006 ◽  
Vol 2 (SPS5) ◽  
pp. 21-24
Author(s):  
Rajesh Kochhar
Keyword(s):  
Geographical Area ◽  
Modern Science ◽  
Deficiency Syndrome ◽  
Multi Stage ◽  
The World ◽  
History Of ◽  
Mind Set ◽  
The 19Th Century ◽  
Astronomical Instrument

AbstractAny international effort to promote astronomy world wide today must necessarily take into account its cultural and historical component. The past few decades have ushered in an age, which we may call the Age of Cultural Copernicanism. In analogy with the cosmological principle that the universe has no preferred location or direction, Cultural Copernicanism would imply that no cultural or geographical area, or ethnic or social group, can be deemed to constitute a superior entity or a benchmark for judging or evaluating others.In this framework, astronomy (as well as science in general) is perceived as a multi-stage civilizational cumulus where each stage builds on the knowledge gained in the previous stages and in turn leads to the next. This framework however is a recent development. The 19th century historiography consciously projected modern science as a characteristic product of the Western civilization decoupled from and superior to its antecedents, with the implication that all material and ideological benefits arising from modern science were reserved for the West.As a reaction to this, the orientalized East has often tended to view modern science as “their” science, distance itself from its intellectual aspects, and seek to defend, protect and reinvent “our” science and the alleged (anti-science) Eastern mode of thought. This defensive mind-set works against the propagation of modern astronomy in most of the non-Western countries. There is thus a need to construct a history of world astronomy that is truly universal and unselfconscious.Similarly, the planetarium programs, for use the world over, should be culturally sensitive. The IAU can help produce cultural-specific modules. Equipped with this paradigmatic background, we can now address the question of actual means to be adopted for the task at hand. Astronomical activity requires a certain minimum level of industrial activity support. Long-term maintenance of astronomical equipment is not a trivial task. There are any number of examples of an expensive facility falling victim to AIDS: Astronomical Instrument Deficiency Syndrome. The facilities planned in different parts of the world should be commensurate with the absorbing power of the acceptor rather than the level of the gifter.

scholarly journals Recurrent Novae — A Review

2015 ◽  
Vol 2 (1) ◽  
pp. 246-251 ◽  
Author(s):  
K. Mukai
Keyword(s):  
Accretion Rate ◽  
Current Understanding ◽  
X Rays ◽  
Symbiotic Star ◽  
Classical Novae ◽  
Extensive Data ◽  
Star Evolution ◽  
Wide Range ◽  
Multi Wavelength ◽  
Recurrent Nova

In recent years, recurrent nova eruptions are often observed very intensely in wide range of wavelengths from radio to optical to X-rays. Here I present selected highlights from recent multi-wavelength observations. The enigma of T Pyx is at the heart of this paper. While our current understanding of CV and symbiotic star evolution can explain why certain subset of recurrent novae have high accretion rate, that of T Pyx must be greatly elevated compared to the evolutionary mean. At the same time, we have extensive data to be able to estimate how the nova envelope was ejected in T Pyx, and it turns to be a rather complex tale. One suspects that envelope ejection in recurrent and classical novae in general is more complicated than the textbook descriptions. At the end of the review, I will speculate that these two may be connected.

scholarly journals AROHANA KRAMA MATRA BASTI IN JANU SANDHIGATA VATA: A CASE STUDY

2021 ◽  
Vol 12 (10) ◽  
pp. 1-6
Author(s):  
Deeya Baboo ◽  
Prajwal Narayan ◽  
Ganesh Puttur
Keyword(s):  
Modern Science ◽  
Joint Space ◽  
Knee Joints ◽  
Long Term Effect ◽  
Walking Time ◽  
Marked Relief ◽  
Flexion And Extension

Ayurveda (Science of life) has explained about the pathogenesis and the treatment of various disorders, the incidence of some of which have increased in the present scenario due to altered diet habits and lifestyle. Janu Sandhigata Vata is one among the Vata Vyadhi which causes a lot of inconvenience and disability in day-to-day activities. It is compared to Osteoarthritis of knee in modern Science. In this case study, a female aged about 57 years presented in the OPD of SSCASRH, Bengaluru was diagnosed with Janu Sandhigata Vata of both the knee joints. Arohana Krama Matra Basti with Prasarini taila was planned as per Sharangadhara’s reference. There was significant improvement in the patient and was evaluated after treatment and also during follow up. There was marked relief with respect to her subjective complaints like pain, improved joint space, walking time, degree of flexion and extension & X ray. This type of Arohana Krama Matra Basti can be adopted in future for planning treatment in Janu Sandhigata Vata and also taken up in a larger group study to check for better relief, long term effect and reduced side effects. The case is further elaborated in the article

scholarly journals Brucellosis morbidity in Russia and Primorsky region

2022 ◽  
pp. 50-55
Author(s):  
G. T. Dzyuba ◽  
Y. E. Skurikhina ◽  
G. A. Zakharova ◽  
A. V. Ponomareva
Keyword(s):  
Average Rate ◽  
Federal District ◽  
Epidemiological Data ◽  
Morbidity Rate ◽  
Disease Rate ◽  
Occupational Groups ◽  
Current State ◽  
Far Eastern ◽  
Epidemiological Situation

Objective: Epidemiological data analysis concerning the spread of brucellosis in Russia and Primorsky Region, study of the manifestations of the epidemic process and the current state of brucellosis issue.Methods: Descriptive epidemiological analysis of materials on infectious morbidity based on state statistical reporting forms No. 1, No. 2 “Information on infectious and parasitic morbidity”.Results: Brucellosis affects workers in the main occupational groups of livestock breeders, workers involved in the processing of livestock, who contact sick animals and other sources of brucellosis infection. Primorsky Region is a territory with an unstable epidemiological situation on brucellosis. A different morbidity rates were registered over the years. However usually it does not exceed the national average rate. In 2009, the morbidity rate counted 27.5% less than in Russian Federation (0.21 and 0.29 per 100,000 respectively), compared to previous years, the average long-term morbidity rate in the region increased by 3.5 times. The disease rate for the period from 2009 to 2019 ranged from 0.05 to 0.21%. In 2012, it exceeded the index in the Far Eastern Federal District (0.1 per 100,000 population). Brucellosis cases were detected among livestock breeders during an extraordinary medical examination due to the bad situation on brucellosis among animals.Conclusions: In recent decades, the epizootic and epidemiological situation on brucellosis remains tense due to the decrease in the number of serological and bacteriological studies among animals and humans, the weakening of veterinary-sanitary control and the formation of new private farms.

Abstract TMP81: Artificial Intelligence Beats Conventional Regression Analysis in Predicting Short and Long Term Risk of Stroke in Patients Undergoing Percutaneous Coronary Interventions

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Pradyumna Agasthi ◽  
Chieh-Ju Chao ◽  
Han Lun Wu ◽  
Farouk Mookadam ◽  
Nithin Venepally ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Regression Analysis ◽  
Area Under The Curve ◽  
Coronary Intervention ◽  
Test Sample ◽  
Training Sample ◽  
Logistic Regression Models ◽  
Percutaneous Coronary ◽  
Short And Long Term

Introduction: Ischemic stroke (IS) causes substantial morbidity and mortality in patients undergoing percutaneous coronary intervention (PCI) with a 5 yr incidence ~ 3%. We sought the test the accuracy of Machine learning (ML) algorithms in predicting IS in patients undergoing PCI. Methods: Mayo Clinic CathPCI registry data were retrospectively analyzed from Jan 2003 - June 2018 including 21,872 patients who underwent PCI. The cohort was randomly divided into a training sample (75%, n=16404) and a unique test sample (25%, n=5468) prior to model generation. The risk prediction model was generated utilizing a random forest algorithm (RF model) on 188 unique variables to predict the risk of IS at 6-month, 1, 2, and 5-year post PCI. Conventional risk factors for stroke were used for logistic regression. The receiver operating characteristic (ROC) curve and area under the curve for the RF and logistic regression models were compared for the test cohort. Results: The mean age was 66.9 ± 12.4 years, and 71% were male. Patient demographics and outcomes are shown in Table 1 . The ROC area under the curve for the RF model was superior compared to the logistic regression model in predicting IS at 6 months, 1,2 and 5 yrs for the test cohort ( Figure 1 .) Conclusions: The RF model accurately predicts short and long term risk of IS and outperforms logistic regression analysis in patients undergoing PCI.

scholarly journals Classical Novae – Before and After Outburst

1988 ◽  
Vol 108 ◽  
pp. 226-231
Author(s):  
Mario Livio
Keyword(s):  
White Dwarf ◽  
Main Sequence ◽  
Orbital Parameters ◽  
Classical Novae ◽  
Classical Nova ◽  
Before And After ◽  
Low Mass ◽  
Orbital Periods ◽  
Thermonuclear Runaway ◽  
Nova Outburst

Classical nova (CN) and dwarf nova (DN) systems have the same binary components (a low-mass main sequence star and a white dwarf) and the same orbital periods. An important question that therefore arises is: are these systems really different ? (and if so, what is the fundamental difference ?) or, are these the same systems, metamorphosing from one class to the other ?The first thing to note in this respect is that the white dwarfs in DN systems are believed to accrete continuously (both at quiescence and during eruptions). At the same time, both analytic (e.g. Fujimoto 1982) and numerical calculations show, that when sufficient mass accumulates on the white dwarf, a thermonuclear runaway (TNR) is obtained and a nova outburst ensues (see e.g. reviews by Gallagher and Starrfield 1978, Truran 1982). It is thus only natural, to ask the question, is the fact that we have not seen a DN undergo a CN outburst (in about 50 years of almost complete coverage) consistent with observations of DN systems ? In an attempt to answer this question, we have calculated the probability for a nova outburst not to occur (in 50 years) in 86 DN systems (for which at least some of the orbital parameters are known).

scholarly journals Classical Novae in the Context of the Evolution of Cataclysmic Binaries

1990 ◽  
Vol 122 ◽  
pp. 313-324
Author(s):  
Hans Ritter
Keyword(s):  
Mass Transfer ◽  
White Dwarf ◽  
White Dwarfs ◽  
Mass Range ◽  
High Mass ◽  
Transfer Rates ◽  
Classical Novae ◽  
Secular Evolution ◽  
Cataclysmic Binaries ◽  
Nova Outbursts

AbstractIn this paper we explore to what extent the TNR model of nova outbursts and our current concepts of the formation and secular evolution of cataclysmic binaries are compatible. Specifically we address the following questions: 1) whether observational selection can explain the high white dwarf masses attributed to novae, 2) whether novae on white dwarfs in the mass range 0.6M⊙ ≲ M ≲ 0.9M⊙ can occur and how much they could contribute to the observed nova frequency, and 3) whether the high mass transfer rates imposed on the white dwarf in systems above the period gap can be accommodated by the TNR model of nova outbursts.

scholarly journals VVV-WIT-01: highly obscured classical nova or protostellar collision?

2020 ◽  
Vol 492 (4) ◽  
pp. 4847-4857
Author(s):  
P W Lucas ◽  
D Minniti ◽  
A Kamble ◽  
D L Kaplan ◽  
N Cross ◽  
...  
Keyword(s):  
Spectral Energy Distribution ◽  
Spectral Energy ◽  
Single Event ◽  
Dark Cloud ◽  
Continuum Source ◽  
Classical Novae ◽  
Classical Nova ◽  
Low Mass ◽  
Compact Array

ABSTRACT A search of the first Data Release of the VISTA Variables in the Via Lactea (VVV) Survey discovered the exceptionally red transient VVV-WIT-01 (H − Ks = 5.2). It peaked before March 2010, then faded by ∼9.5 mag over the following 2 yr. The 1.6–22 μm spectral energy distribution in March 2010 was well fit by a highly obscured blackbody with T ∼ 1000 K and $A_{K_s} \sim 6.6$ mag. The source is projected against the Infrared Dark Cloud (IRDC) SDC G331.062−0.294. The chance projection probability is small for any single event (p ≈ 0.01–0.02), which suggests a physical association, e.g. a collision between low mass protostars. However, blackbody emission at T ∼ 1000 K is common in classical novae (especially CO novae) at the infrared peak in the light curve due to condensation of dust ∼30–60 d after the explosion. Radio follow-up with the Australia Telescope Compact Array detected a fading continuum source with properties consistent with a classical nova but probably inconsistent with colliding protostars. Considering all VVV transients that could have been projected against a catalogued IRDC raises the probability of a chance association to p = 0.13–0.24. After weighing several options, it appears likely that VVV-WIT-01 was a classical nova event located behind an IRDC.

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