Close binary stars have attracted a lot of attention due to the peculiarities of their evolution. The development of these systems is associated with several paradoxes that are of particular interest to scientists. More so, it has been acknowledged that most stars are found in binary and multiple systems (Podsiadlowski 45). Therefore, it is essential to make sure that all properties of this system are properly researched as they can have a certain impact on the Earth as well.
Researchers managed to examine various phenomena taking place in the universe through the close analysis of binary stellar systems. Binary stars are usually constituted by two “compact stellar remnants” (Negu and Tessema 223). These components are usually remnants of black holes, neutron stars and, the so-called, white dwarfs. At the same time, these stars can consist of two non-degenerate stars, one stellar remnant (or compact star) and one non-degenerate star, or two compact stars (Podsiadlowski 45). These two bodies move around one gravity center. Several processes affect the development of the binary stellar system.
There are several ways a binary star can form. For instance, a star with a significant mass can capture another stellar body through its magnetic field. However, researchers agree that these cases are very rare (Webbink 234). In the vast majority of cases, envelopes of gas, compact stars, and dust usually split into several parts that later evolve into two stars. Interestingly, there are three bodies necessary to develop a binary system as the third body ensures the gravitation that keeps the two other components apart. As has been mentioned above the two stars circulate one orbit, and they can be at different distances.
If the stars are quite far from each other, they often develop in a way all other separate stars evolve (Webbink 234). It is necessary to stress that the two components of the system have little or even no effect on each other due to the distance between them. In many cases, these stars move far from each other and leave the binary system. They start evolving as separate stars. Close binary systems have attracted the most attention of researchers as these systems are constantly developing. The two stars affect each other’s development through their gravitation fields as well as mass transfer.
Mass transfer is the key process that contributes to the development of binary stars. Negu and Tessema note that this phenomenon is especially remarkable when it comes to the evolution of binary stars constituted by a degenerate star and another component (223).
The mass transfer occurs due to significant gravitational and magnetic fields of the objects involved as well as the influence of such phenomena as pulsed X-ray emission, “novae outbursts” and nuclear burning (Negu and Tessema 223). It is well known that mass plays a significant role in the process of binary stars’ formation (Fragner and Nelson 1). The two stars in the system have their mass and gravitation fields that have an impact on each other.
This interaction is associated with the phenomenon called Roche lobes (Negu and Tessema 223). The Roche lobe refers to the space controlled by a star by its gravitational field. In each binary system, there are two Roche lobes. The body with a larger mass has a bigger Roche lobe. In the binary system, the two Roche lobes meet, and this point is referred to as a Lagrange point. This is an important milestone as the matter reaching the Lagrange point transfers to the other star.
It is possible to note that this point is the place where mass transfer occurs. It is necessary to add that the stars may lose the matter as a result of winds and emissions. For instance, the wind can blow away gases from one star, and when they reach the Lagrange point, the gravity field of the other star captures them. There can also be collisions with other objects that can lead to the partial destruction of one of the stars and the occurrence of parts that can reach the other star’s Roche lobe.
The mass transfer is also associated with the so-called Algol paradox. The paradox is linked to the interaction between the stars within the binary system (Podsiadlowski 57). The stars within the system are often of different sizes. The larger star has a stronger gravity field, and it increases in mass as it captures matter through its gravitation field. Eventually, the bigger component becomes a giant. At the same time, the giant fills in its Roche lobe, and, hence, its matter reaches the Lagrange point.
The matter that reaches this point is transferred to the other body. Thus, the bigger star loses its mass that is transferred to the smaller body. The two objects are also at different stages of their development, which is also a paradox as the two stars are formed simultaneously.
The evolution of the binary system often ends in its disruption. Several factors contribute to this event. The binary system can be destroyed by external bodies. Some bodies (a big comet, another system with a stronger gravitation field, and so on) can disrupt the binary system’s gravitation, which will make the two bodies move away from each other. As has been mentioned above, if the stars in a binary system are far from each other they start developing as separate objects. Apart from that, the interaction of the two gravitation fields can result in the ejection of one of the stars that move at a significant pace. These ejected stars are referred to as runaway stars (Podsiadlowski 53).
Finally, at some point in their development, stars explode, and the other star in the system is affected considerably (depending on the size of the stars and their mass). The bigger star is, the more impact is produced. The other object can be destroyed. The distance between the objects also affects the impact produced by the disruption of one of the stars.
In conclusion, it is possible to note that binary stars are systems that can help people understand the processes that take place in the universe. The evolution of close binary stars is remarkable as it is associated with the interaction of multiple objects and some paradoxes. Researchers have managed to explain the associated processes and describe various peculiarities of these systems. At the same time, it is still important to continue research as people should be ready to address any challenges that the Earth face in the future. It is vital to understand all the processes and the nature of all objects existing in the universe to be able to face any challenges.
Works Cited
Fragner, Moritz and Richard Nelson. “Evolution of Warped and Twisted Accretion Discs in Close Binary Systems.” Astronomy and Astrophysics 511 (2010): 1-23. Print.
Negu, Sablu Humne and Solomon Tessema. “Mass Transfer in Binary Stellar Evolution and Its Stability.” International Journal of Astronomy and Astrophysics 5.1 (2015): 222-241. Print.
Podsiadlowski, Philipp. “The Evolution of Binary Systems.” Accretion Processes in Astrophysics. Ed. Ignacio Gonzalez Martinez-Pais, Tariq Shahbaz and Jorge Casares Velazquez. New York: Cambridge University Press, 2014. 45-89. Print.
Webbink, Ronald F. “Common Envelope Evolution Redux.” Short-Period Binary Stars: Observations, Analyses, and Results. Ed. Eugene F. Milone, Denis A. Leahy and David W. Hobill. New York: Springer Science & Business Media, 2008. 233-257. Print.