A solar system with two suns? It could be the beginning of a very interesting sci-fi movie. But what if it was true? Well, it a special, celestial way, it actually is. By the time humans were spreading from Africa into Eurasia, a stellar neighbour was taking a look into our solar system, checking for long lost brothers, maybe. This happened “only” 70,000 years ago, but in cosmic time, it’s close to a foggier type of a yesterday. Waving goodbye is actually an option, because the star might as well respond gratefully. Maybe Neanderthals already did it, because taking into consideration the time frame, the humanity were about to start developing languages, tools and create primitive cave paintings that will offer useful information to the next generations.
The WISE, Nasa’s wide-field Infrated Survery Explorer has found in 2013 a red dwarf that was orbited by a brown dwarf accomplice. The star has been nicknamed Scholz’s star, as an honorific reward for the German explorer that has discovered it. In 2013 the star was found speeding away from the Earth at a distance of 19.6 light years away, according to Nature.
The star has come quite close to our solar system, as a paper published in Astrophysical Journal Letters had stated. The distance has been estimated to 52,000 astronomical units, where one astronomical units is considered to be equal to the distance between Earth and our sun. Right now, the Scholz’s star is at 20 light-years away, in comparison with the nearest star that we know of today, the Proxima Centauri, that is 4.2 light years away. As it has moved further away from our solar system, scientists believe that the star has showered it with comets. Not very polite for such an old friend. However, explorers have measured the stars’ sideways motion across the sky, action that is called “proper motion”, finding out it has been moving very slowly. Once again, “slow”is different in space, taking into account that the star has travelled with about 80 kilometers per second.
Astronomers have put a lot of faith in the Gaia satellite, which has been launched by The European Space Agency and which will be showing a lot of what is happening in our neighbor’s “courtyard”, as far as stars are concerned. We will soon be able to know who has also visited our solar system before, what kind of influence it had and who will be the next ones to pass us by and when.
Image Source: Rochester