scholarly journals Statistical analysis of period-eccentricity distribution for large samples of close binaries from Kepler, CoRoT and SB9 databases

2019 ◽  
Vol 82 ◽  
pp. 127-133
Author(s):  
J. Sztakovics ◽  
E. Forgács-Dajka ◽  
T. Borkovits ◽  
T. Hajdu ◽  
G. Marschalkó
Keyword(s):  
Statistical Analysis ◽  
Space Missions ◽  
Double Star ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Close Binaries ◽  
Large Samples ◽  
Dynamical Parameters ◽  
The Difference

Period–eccentricity distribution of eccentric eclipsing binaries (eEB) has inevitable importance in the study of the different kinds of tidal circularization (and synchronization) processes. Recent space missions provide a large amount of continuous and precise light curves, which enable us to determine several accurate stellar and dynamical parameters for thousands of freshly discovered eEBs. For statistical analysis we developed a fast, automated, although approximating method for determining eccentricity and argument of periastron from the displacement of the secondary minima and the difference of primary and secondary eclipse durations for large samples of eclipsing lightcurves. Applying this method to several hundreds of recently discovered eEBs in the fields of the primordial and secondary Kepler and also the CoRoT missions, we present a comprehensive statistical analysis of the period–eccentricity relation for different subgroups of these double star systems.

scholarly journals Starspot migration in close binaries: A fast parameters evaluation from large sky surveys

2016 ◽  
Vol 12 (S325) ◽  
pp. 274-277
Author(s):  
B. Debski ◽  
S. Zola
Keyword(s):  
Visual Inspection ◽  
Magnetic Activity ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Close Binaries ◽  
Intrinsic Variability ◽  
Sky Surveys ◽  
Orbital Periods

AbstractWe developed a method that allows to classify the light curves of eclipsing binaries of the W UMa type (EW) with respect to their intrinsic variability. The algorithm measures several features of light curves, such as the amplitude of the O’Connell effect, the separation and location of maxima brightness as well as depths of the minima in subsequent orbital periods. This method is capable of distinguishing systems with presumed magnetic activity present from these without it, as well as recognizing systems with starspots migration and those with other types of intrinsic variability manifestation. The classification is done in an automatic way without a time consuming, visual inspection of light curves.

scholarly journals Seeing Double in the Local Group: Extragalactic Binaries

2005 ◽  
Vol 13 ◽  
pp. 446-446
Author(s):  
Edward F. Guinan
Keyword(s):  
Binary Systems ◽  
Local Group ◽  
Magellanic Clouds ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Close Binaries ◽  
Major Advance ◽  
Future Expectations ◽  
High Quantum ◽  
Orbital Periods

Photographic surveys of the Magellanic Clouds and the M31 carried decades ago discovered ~200 close binaries. In most cases the photographic light curves are good enough only to identify the stars as close (mostly eclipsing) binaries and to estimate orbital periods and binary type. Except for a few cases, little useful information may be obtained from these stars except to be reassured that eclipsing binary (EB) systems are present in other galaxies. However a major advance occurred with the advent of high quantum efficient CCDs. Because of this an explosion in the number of known extragalactic binaries occurred during the 1990s as offshoots of photometric microlensing surveys such as EROS, MACHO, and OGLE. Now over 10 000 extragalactic EBs have been identified. Also, photometric surveys of M31 and M33 (e.g. DIRECT) are discovering many more 19-20th mag eclipsing/close binaries. Over the next decade it is expected that ~1 million new binary systems will be identified in these galaxies. In this overview I will discuss recent advances and future expectations in the studies of extragalactic binaries

scholarly journals Rotational Properties and Synchronization in Early-Type Close Binaries

1985 ◽  
Vol 111 ◽  
pp. 401-402
Author(s):  
G. Giuricin ◽  
F. Mardirossian ◽  
M. Mezzetti
Keyword(s):  
Angular Velocity ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Spectroscopic Binaries ◽  
Close Binaries ◽  
Early Type ◽  
Orbital Inclination ◽  
Eccentric Orbits ◽  
The Mean ◽  
The Absolute

We have rediscussed the synchronism between rotation and revolution in close binaries by an inspection of the published projected rotational velocities V sin i of about 250 early-type (from 0 to F5) eclipsing and double-lined spectroscopic binaries. Corrections of the V sin i - values (which are mainly taken from the catalog of Uesugi and Fukuda, 1982) for the aspect effect is straightforward for the eclipsing binaries with analyzed light-curves; in the other cases we have estimated the value of the orbital inclination angle i from the primary's minimum mass M1 sin3 i on the assumption that its mass follows Straižys and Kuriliené's (1981) mass-spectrum relations for different luminosity classes. For the components of non-eclipsing binaries, for which the absolute radii are not directly known, we have adopted values of the absolute radii in accordance with Straižys and Kuriliené's (1981) radius-spectrum relations for different luminosity classes. By using our estimates of the radii, for each component we have evaluated the synchronized velocity Vk (corresponding to the mean orbital angular velocity) and the pseudosynchronized velocity Ve, which corresponds to a synchronization with the instantaneous orbital angular velocity at periastron of an eccentric orbit; in close binaries with appreciably eccentric orbits synchronization is attained with V/Vk>1 and it is probably quickly reached at periastron (Hut 1981).

scholarly journals The asymmetric light curves of the GSC 2764 1417 (And), GSC 3355 0394 (Per) and GSC 2537 0520 (Psc)

2009 ◽  
Vol 5 (S264) ◽  
pp. 75-77
Author(s):  
Ronald G. Samec ◽  
Evan R. Figg ◽  
Reid Melton ◽  
Christa M. Labadorf ◽  
Jess Miller ◽  
...  
Keyword(s):  
Eclipsing Binaries ◽  
Light Curves ◽  
Close Binaries ◽  
Short Period ◽  
Solar Type

AbstractSolar-type variability is enhanced in short period close binaries with increased dynamo driven activity. This activity is studied in our analysis of recent light curves taken of the newly discovered eclipsing binaries GSC 2764 1417 (And), GSC 3355 0394 (Per) and GSC 2537 0775 (CVn).

scholarly journals Statistical Investigation of Physical and Geometrical Parameters in Close Binaries using the ASAS Database

2011 ◽  
Vol 7 (S282) ◽  
pp. 73-74 ◽  
Author(s):  
J. Nedoroščik ◽  
M. Vaňko ◽  
Š. Parimucha
Keyword(s):  
Light Curve ◽  
Fourier Coefficients ◽  
Variable Stars ◽  
Statistical Investigation ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Close Binaries ◽  
Geometrical Parameters ◽  
Statistical Research ◽  
Pulsating Variable Stars

AbstractThe main goal of this work was to find dependencies between Fourier coefficients, which were developed by light curve fitting with Fourier polynomials. The light curves were acquired from the ASAS database (All Sky Automated Survey). In this statistical research it was necessary to sort and modify these data, because light curves of eclipsing binaries are just part of a bigger database, which contains the light curves of pulsating variable stars, novas etc. It was required to phase and normalize all of our light curves, that it could be possible to use a program to fit light curves with Fourier coefficients. Thereafter, we were looking for relations between Fourier coefficients.

The Effect of T-Commerce Scarcity Messages and Price Policies on Attitudes and Purchase Intention

2019 ◽  
Vol 118 (1) ◽  
pp. 42-47
Author(s):  
KwangSeok Han
Keyword(s):  
Statistical Analysis ◽  
Purchase Intention ◽  
Time Limit ◽  
Discount Factor ◽  
Limited Time ◽  
Price Discount ◽  
Discount Price ◽  
Strategic Plans ◽  
Factor Design ◽  
The Difference

Background/Objectives: This study investigated differences in the attitude of users according to type of scarcity message and price discount conditions to compose T-commerce sales messages and search for effective strategic plans. Methods/Statistical analysis: This study empirically verifies the difference in promotion attitude and purchase intention between the type of T-Commerce scarcity message (quantity limit message / time limit message) and the price discount policy (price discount / non-discount) message. For this purpose, 2 (scarcity type: limited quantity, limited time) X 2 (with or without price discount: price discount, no price discount) factor design between subjects was used.

scholarly journals SuperWASP variable stars: classifying light curves using citizen science

2021 ◽  
Vol 502 (1) ◽  
pp. 1299-1311
Author(s):  
Heidi B Thiemann ◽  
Andrew J Norton ◽  
Hugh J Dickinson ◽  
Adam McMaster ◽  
Ulrich C Kolb
Keyword(s):  
Variable Stars ◽  
Eclipsing Binaries ◽  
Light Curves ◽  
Data Set ◽  
Resultant Data ◽  
Sky Survey ◽  
Short Period ◽  
Contact Binaries ◽  
Analysis Of Results

ABSTRACT We present the first analysis of results from the SuperWASP variable stars Zooniverse project, which is aiming to classify 1.6 million phase-folded light curves of candidate stellar variables observed by the SuperWASP all sky survey with periods detected in the SuperWASP periodicity catalogue. The resultant data set currently contains >1 million classifications corresponding to >500 000 object–period combinations, provided by citizen–scientist volunteers. Volunteer-classified light curves have ∼89 per cent accuracy for detached and semidetached eclipsing binaries, but only ∼9 per cent accuracy for rotationally modulated variables, based on known objects. We demonstrate that this Zooniverse project will be valuable for both population studies of individual variable types and the identification of stellar variables for follow-up. We present preliminary findings on various unique and extreme variables in this analysis, including long-period contact binaries and binaries near the short-period cut-off, and we identify 301 previously unknown binaries and pulsators. We are now in the process of developing a web portal to enable other researchers to access the outputs of the SuperWASP variable stars project.

Analysis of the breeding records of a herd of pigs

1954 ◽  
Vol 45 (1) ◽  
pp. 19-27 ◽  
Author(s):  
R. Braude ◽  
P. M. Clarke ◽  
K. G. Mitchell
Keyword(s):  
Statistical Analysis ◽  
Large White ◽  
Seasonal Differences ◽  
Significant Difference ◽  
The Mean ◽  
The Difference ◽  
Length Of Gestation

1. A survey and. statistical analysis of the records of litters born in the N.I.R.D. herd of Large White pigs over a period of 16 years are presented.2. The mean length of gestation was 114 days for both gilts and sows.3. The mean numbers of pigs born alive and born dead per litter from gilts, 10·0 and 0·2 respectively, were both significantly smaller than the corresponding figures for sows, 11·8 and O·8. No seasonal differences were found.4. The mean total losses of pigs from birth to weaning at 8 weeks were 29·5% of pigs born alive. The losses in litters from gilts, 23·0%, were significantly smaller than in litters from sows, 31·0%. The losses during the winter months both for gilts, 32·5%, and for sows, 35·9%, were significantly higher than during the summer months, 19·4% and 26·7% for gilts and sows respectively.5. Over 50% of the total losses were due to crushing by the dam, 74·1% of the losses from this cause occurring during the first 48 hr. after birth.6. The mean number of pigs weaned per litter was 8·0. The difference between the number weaned per litter from gilts, 7·7, and per litter from number of pigs was weaned per litter from sows during the summer months, 8·7, than during the winter months, 7·4.7. There was no significant difference between the number of male and of female pigs weaned.8. The mean weight at weaning was 29·9 lb., male pigs, 30·3 lb., being significantly heavier than females, 29·51b. Pigs in litters from gilts, 27·81b., were significantly lighter at weaning than those from sows, 30·0 lb., and for both gilts and sows, pigs reared during the summer months, 29·7 and 31·8 lb. respectively, were significantly heavier than those reared during the winter months, 25·9 and 28·2 lb. respectively.

scholarly journals Characteristics of anteroposterior curvatures of the spine in soccer and futsal players

2017 ◽  
Vol 18 (4) ◽  
Author(s):  
Krystyna Chromik ◽  
Anna Burdukiewicz ◽  
Jadwiga Pietraszewska ◽  
Aleksandra Stachoń ◽  
Paweł Wolański ◽  
...  
Keyword(s):  
College Students ◽  
Statistical Analysis ◽  
Injury Prevention ◽  
Analysis Of Variance ◽  
Statistical Significance ◽  
Body Posture ◽  
Soccer Players ◽  
Prevention Training ◽  
The Difference ◽  
Post Hoc

AbstractPurpose. The aim of the study was to determine differences in anteroposterior spine curvatures between futsal players, soccer players, and non-training students. The results may contribute to the development of present-day knowledge of posturometry, and its implementation in training can help reduce the risk of body posture disorders in athletes. Methods. The examined group consisted of 48 athletes and 38 non-training college students. Body posture parameters were measured with the use of Posturometr-S. The normality of distribution was checked with the Shapiro-Wilk test, and the differences between the groups were measured with ANOVA and the Bonferroni post-hoc test. The level of statistical significance was set at p < 0.05. Results. The analysis of angle values revealed the widest and most similar measurements in the group of futsal players and soccer players. The analysis of variance proved statistically significant differences between the soccer players and futsal players (p = 0.003). The difference between the soccer players and non-training students was statistically significant. The highest γ angular value was measured in non-training students, followed by futsal players and soccer players. The statistical analysis revealed significant differences between the non-training students and futsal players, as well as non-training students and soccer players (p < 0.001). Conclusions. A complex assessment of athletes’ body posture is crucial in injury prevention. Training overloads may often lead to disorders of the organ of locomotion and affect the correct body posture in athletes. This, in turn, may result in pains and injuries.

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