PERIOD VARIATIONS AND POSSIBLE THIRD COMPONENTS IN THE ECLIPSING BINARIES AH TAURI AND ZZ CASSIOPEIAE
Journal Title: Odessa Astronomical Publications - Year 2018, Vol 31, Issue
Abstract
In our research, we investigated two variable stars: AH Tau and ZZ Cas. They are eclipsing binary stars of W Ursae IMajories and Lyrae types. The period between eclipses of these stars changes with time. The reason for steady changes of the period could be the mass transfer (the flow of matter) between components of these stellar systems. For ZZ Cas the changes of the period are cyclic. That is why we assume the cyclic changes could be caused by the presence of the hypothetical third component (either a small star or a large planet). The cyclic changes of the period for AH Tau superimpose on steady ones (the period decrease). Thus we assume the third component and mass transfer are present. We also assume that the third components do not take part in the eclipses. However, due to their gravity, they make the visible close binary systems rotate and become closer or further to an observer. This explanation is called Light-Time Effect (LTE). Generally, an orbit of a third component is not a circle, but an ellipse and it is inclined relatively to the observer’s line of sight. Using special plot called O-C curve we estimated the parameters of a third component’s orbit such as a semi-major axis, an eccentricity, angles of orientation and a period of a third component’s rotation. The O-C curve is the plot which shows how the difference between an observed and calculated moment of minimal brightness changes during a long period of time (usually it is several decades). To do this we created a modeling computer program using the computer language Python. In addition, we can calculate errors of third component’s orbit parameters and even estimate its mass. The values of masses of the third components within errors of calculations show that the third components are probably stars. All these calculations were made using all available data from international database BRNO (Brno Regional Network for Observers). Moreover, we used moments of minima which we calculated as the result of observation processing from AAVSO database (American Association of Variable Stars Observers). These results are provided in the tables and plots.
Authors and Affiliations
D. E. Tvardovskyi, V. I. Marsakova, I. L. Andronov, L. S. Shakun
Keywords
Related Articles
- EP ID EP603648
- DOI 10.18524/1810-4215.2018.31.145280
- Views 55
- Downloads 0
QUANTUM MODEL OF A CHARGED BLACK HOLE
A canonical approach for constructing of the classical and quantum description spherically-symmetric con guration gravitational and electromagnetic fields is considered. According to the sign of the square of the Kodama...
THE INVESTIGATION OF THE FON3 CATALOGUE DATA USING WIELEN METHOD
The method described by Wielen is very efficient provided the data under comparison are independent quantities. In this case, dispersion of position or magnitude differences is equal to the sum of their dispersions, beca...
ISENTROPIC "SHOCK WAVES" IN NUMERICAL ASTROPHYSICS
Numerical simulations of the cold supersonic flows in different astrophysical problems meets with the loss of precision difficulty. For to overcome the difficulty it was suggested earlier to use conservation entropy equa...
IS THERE 9-TH PLANET IN OUR SOLAR SYSTEM?
Brown and Batygin informed on indirect evidence of existence of the ninth planet in Solar System (SS). Some evidence pointing on its possible mass in 10 Earth’s mass; its distance from Sun at perihelion can be ~200AU, at...
HIGH-PRECISION FOLLOW-UP OBSERVATIONS OF NEAR-EARTH OBJECTS
Main objective of the study is orbit refinement of Near-Earth Objects (NEOs) as part of the global task of asteroid-cometary hazard. We present the latest results of ongoing high-precision astrometric follow-up observati...