Castor, about 51 light years away from us, is one of the brightest stars in the sky, though it is not among the brightest. However, this star, which looks like a single star to our eyes, is among the most interesting star systems with its 6 members.
The two brightest components of the system consist of two Class A hot stars, which are orbited about 460 years around a common gravitational center. The system, thanks to the light of these two stars with 2.2 masses of solar mass, reaches a visible brightness with the naked eye.
The temperature of the star, called Castor A1, is 10,000 degrees Celsius and the energy it radiates is 50 times the size of the Sun. Castor B1 has a surface temperature of 8,000 degrees Celsius and 14 times more energy than the Sun.
However, the two stars around each other are not alone, because there are some M-class red dwarf stars all around them. One of these two stars with 0.5 solar masses and a temperature of about 3,500 degrees Celsius is orbiting Castor A1 and the other Castor B1. This makes Castor a typical 4-star system.
Also, red dwarf stars are very close to big stars. So much so that they complement each other's orbits in a few days. I mean, the dwarf stars are in some danger.
But the job does not end here, because there is a system of binary stars that fills them around, much farther than the system that these 4 stars have created.
Castor C1 and Castor C2, consisting of two red dwarf stars, which are close to each other's joint gravitational center (2.7 million km), only 19 hours in total, turn around this quadrant system over a wide orbit. Since these two stars are so close together, a possible planetary system must be in the form of a system in which both stars are in the center, and the planets are surrounded by these two stars.
In this case, if there is a planet in Castor C1 and C2 that is viable, it will be possible to see the two stars angularly close to each other when viewed from that planet, but to be able to distinguish the two from each other only during the sunset and with careful consideration. The same goes for Castore and Castor B. It will be very difficult to see red dwarf stars.
Castor, a young star system and stars are quite young. Castor A1 and Castor A2 stars, very bright but short-lived stars. In the next 300 million years, Castor A1 will first become a red giant star after 600 million years, then Castor B1 will form a planetary nebula and end their lives as a white dwarf. If Castor A1 and Castor B1 do not swallow dwarf stars in their circles as they turn into red giants, the remaining 4 red dwarf stars will survive for hundreds of billions of years.
Since the system is very young and two stars of type A are now raiding the system, it is not possible to talk about the possibility of life on any planet there. All stars are newly formed, and possible planets are still in the process of development / cooling, such as hell where meteor showers hit planets like a storm. However, planets likely to exist around red dwarf stars after a few billion years may become suitable for life.
