MAVKA: Investigation of stellar brightness extrema approximation stability for various methods

Andrych, Kateryna D.; Tvardovskyi, D. E.; Chinarova, L. L.; Андронов, И. Л.

doi:10.31577/caosp.2020.50.2.557

Cited by 2 publications

(3 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The most used is the Kwee & van Woerden method (Kwee & van Woerden 1956) that is not suitable when the minimum is covered poorly. There are also methods that represent binary eclipses by simple quadratic or quartic functions near minimum (Rappaport et al 2013;Borkovits et al 2016) and methods that generate eclipse templates such as the semi automatic fitting procedure (AFP; Zasche et al 2014), the template function as proposed by Mikulášek (2015) or any high order polynomial fit as used by Conroy et al (2014) and the MAVKA software for approximating moments of extrema (both maxima and minima; Andrych et al 2020). Here we present an automated procedure to calculate the times of eclipse minima by constructing and fitting a Gaussian function template to both primary and secondary eclipses in the following form:…”

Section: Times Of Minimum Light Computationmentioning

confidence: 99%

Detection of period variations of eclipsing binaries in the Catalina Sky Survey

Παπαγεωργίου

Catelan

Christopoulou

et al. 2021

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We present 126 eclipsing binary candidates among 4683 Catalina Sky Surveys (CSS) detached and semi-detached eclipsing binary systems (EBs) showing cyclic or quadratic period variations over a 12 yr time span. By using inverse Gaussian profiles of the eclipses coupled with a Markov Chain Monte Carlo procedure, times of minima (ToM) were calculated and diagrams with eclipse timing variations (ETVs) were constructed. Numerical tests were performed, involving synthetic EBs with period variations generated by the PHOEBE 2.0 engine and actual data for EBs with well-known period variations from the literature, to verify that the calculation of ToM variations for our CSS systems is reliable. A total of 63 out of the 126 EBs show likely cyclic ETVs, while the remainder present quadratic behaviour instead. Periods, amplitudes, period change rates, and associated errors were determined by using sinusoidal and parabolic models. Twelve out of the 63 EBs (19 per cent) that appear to exhibit periodic ETVs are low-mass candidates. Additionally, 4 out of 126 also have maximum quadrature light variations. The possibility that the cyclic variations are caused by the light travel time effect due to the presence of a tertiary companion is investigated. The possible nature of the quadratic ETVs is also discussed.

show abstract

Section: Times Of Minimum Light Computationmentioning

confidence: 99%

Detection of period variations of eclipsing binaries in the Catalina Sky Survey

Παπαγεωργίου

Catelan

Christopoulou

et al. 2021

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…Andronov & Andrych (2014)). Andrych et al (2020b) and Tvardovskyi et al (2020a) investigated the approximation stability for various methods implemented in MAVKA.…”

Section: Algorithms Used In Mavkamentioning

confidence: 99%

“…An example of such combined study is two eclipsing binaries V454 Dra and V455 Dra in the field of cataclysmic variable DO Draconis is shown by Kim et al (2020).…”

Section: Eclipsing Binary Systemsmentioning

confidence: 99%

Astroinformatics: Statistically Optimal Approximations of Near-Extremal Parts with Application to Variable Stars

Андронов

Andrych

Chinarova

et al. 2020

ComBAO

View full text Add to dashboard Cite

The software MAVKA is described, which was elaborated for statistically optimal determination of the characteristics of the extrema of 1000+ variable stars of different types, mainly eclipsing and pulsating. The approximations are phenomenological, but not physical. As often, the discovery of a new variable star is made on time series of a single-filter (single-channel) data, and there is no possibility to determine parameters needed for physical modelling (e.g. temperature, radial velocities, mass ratio of binaries). Besides classical polynomial approximation "AP" (we limited the degree of the polynomial from 2 to 9), there are realized symmetrical approximations (symmetrical polynomials "SP", "wall-supported" horizontal line "WSL" and parabola "WSP", restricted polynomials of non-integer order based on approximations of the functions proposed by Andronov (2012) and Mikulasek (2015) and generally asymmetric functions (asymptotic parabola "AP", parabolic spline "PS", generalized hyperbolic secant function "SECH" and "log-normal-like" "BSK"). This software is a successor of the "Observation Obscurer" with some features for the variable star research, including a block for "running parabola" "RP" scalegram and approximation. Whereas the RP is oriented on approximation of the complete data set. MAVKA is pointed to parts of the light curve close to extrema (including total eclipses and transits of stars and exoplanets). The functions for wider intervals, covering the eclipse totally, were discussed in Andronov (2017). Global and local approximations are reviewed in Andronov (2020). The software is available at http://uavso.org.ua/mavka and https://katerynaandrych.wixsite.com/mavka. We have analyzed the data from own observations, as well as from monitoring obtained at ground-based and space (currently, mainly, TESS) observatories. It may be used for signals of any nature.

show abstract

MAVKA: Investigation of stellar brightness extrema approximation stability for various methods

Cited by 2 publications

References 10 publications

Detection of period variations of eclipsing binaries in the Catalina Sky Survey

Detection of period variations of eclipsing binaries in the Catalina Sky Survey

Astroinformatics: Statistically Optimal Approximations of Near-Extremal Parts with Application to Variable Stars

Contact Info

Product

Resources

About