Alpha Centauri is the target of spacecraft flights in many science fiction works. This star closest to us refers to the celestial drawing, embodying the legendary centaur Chiron, according to Greek mythology, the former teacher of Hercules and Achilles.
Modern researchers, like writers, tirelessly return to this star system in their thoughts, since it is not only the first candidate for a long-term space expedition, but also the possible owner of a populated planet.
Structure
The Alpha Centauri star system includes three space objects: two stars with the same name and designations A and B, as well as Proxima Centauri. Such stars are characterized by the close location of two components and the remote - the third. Proxima is just the last one. The distance to Alpha Centauri with all its elements is approximately 4.3 light years. There are currently no stars closer to Earth. At the same time, the fastest way to fly to Proxima: we are separated by only 4.22 light years.
Solar relatives
Alpha Centauri A and B differ from their companion not only in their distance from the Earth. They, unlike Proxima, are in many ways similar to the Sun. Alpha Centauri A or Rigel Centaurus (translated as "Centaur's foot") is the brighter component of the pair. Toliman A, as this star is also called, is a yellow dwarf. From the Earth, it is perfectly visible, since it has a zero magnitude. This parameter makes it the fourth brightest spot in the night sky. The size of the object is almost the same as the sun.
The star Alpha Centauri B is inferior to our luminary in mass (about 0.9 of the values of the corresponding parameter of the Sun). It belongs to the objects of the first magnitude, and its luminosity level is approximately two times less than that of the main star of our piece of the Galaxy. The distance between two neighboring companions is 23 astronomical units, that is, they are located 23 times farther apart than the Earth is from the Sun. Toliman A and Toliman B together rotate around the same center of mass with a period of 80 years.
Recently opened
Scientists, as already mentioned, have high hopes for the discovery of life in the vicinity of the star Alpha Centauri. The planets supposed to exist here may resemble the Earth in the same way that the components of the system themselves resemble our star. Until recently, however,no such cosmic bodies were found near the star. The distance does not allow direct observation of the planets. Obtaining evidence of the existence of an Earth-like object became possible only with the improvement of technology.
Using the radial velocity method, scientists were able to detect very small fluctuations of Toliman B, arising under the influence of the gravitational forces of the planet revolving around it. Thus, evidence was obtained for the existence of at least one such object in the system. The wobbles caused by the planet show up as a shift of 51 cm per second forward and then back. Under the conditions of the Earth, such a movement, even of the largest body, would be very noticeable. However, at a distance of 4.3 light years, detection of such a wobble seems impossible. However, it was registered.
Sister Earth
The found planet revolves around Alpha Centauri B in 3, 2 days. It is located very close to the star: the radius of the orbit is ten times smaller than the corresponding parameter characteristic of Mercury. The mass of this space object is close to that of the earth and is approximately 1.1 of the mass of the Blue Planet. This is where the similarity ends: the proximity, according to scientists, suggests that the emergence of life on the planet is impossible. The energy of the luminary reaching its surface heats it up too much.
Nearest
The third component of the star system that makes the entire constellation famous is Alpha Centauri C or Proxima Centauri. The name of the cosmic body in translation means "nearest". Proxima stands at a distance of 13,000 light years from its companions. This is an object of the eleventh magnitude, a red dwarf, small (about 7 times smaller than the Sun) and very dim. It is impossible to see it with the naked eye. Proxima is characterized by a “restless” state: a star is capable of changing its brightness twice in a few minutes. The reason for this "behavior" in the internal processes occurring in the depths of the dwarf.
Dual position
Proxima has long been considered the third element of the Alpha Centauri system, orbiting the pair A and B in about 500 years. However, recently the opinion is gaining strength that the red dwarf has nothing to do with them, and the interaction of three cosmic bodies is a temporary phenomenon.
The reason for doubts was the data that said that a close-knit pair of stars does not have enough gravitational attraction to hold Proxima as well. The information received in the early 90s of the last century needed additional confirmation for a long time. Recent observations and calculations of scientists did not give a definite answer. According to assumptions, Proxima can still be part of a triple system and move around a common center of gravity. At the same time, its orbit should look like an elongated oval, and the most distant point from the center is the one in which the star is observed now.
Projects
Be that as it may, it is planned to fly to Proxima firstqueue when possible. The journey to Alpha Centauri, with the current level of development of space technology, can last more than 1000 years. Such a time period is simply unthinkable, so scientists are actively looking for ways to reduce it.
A NASA research team led by Harold White is developing Project Speed, which should result in a new engine. Its feature will be the ability to overcome the speed of light, so that the flight from the Earth to the nearest star will be only two weeks. Such a miracle of technology will become a real masterpiece of the close-knit work of theoretical physicists and experimenters. So far, however, a ship that overcomes the speed of light is a matter of the future. According to Mark Millis, who once worked at NASA, such technologies, given the current speed of progress, will not become a reality until two hundred years later. Reducing the period is possible only if a discovery is made that can radically change the existing ideas about space flights.
For now, Proxima Centauri and its companions remain an ambitious goal, unattainable in the near future. Technique, however, is constantly being improved, and new information about the characteristics of the star system is clear evidence of this. Already today, scientists can do much of what 40-50 years ago and could not even dream of.
