Our Sun is a kind of galactic traveler. It rotates in one of the spiral arms of the Milky Way, completing a full revolution every 230 million years. The closest star to us, Proxima Centauri, is 4.2 light-years away — so far away that even the fastest spacecraft would take more than 7,000 years to fly to it.
However, in our galaxy, the Sun looks anomalous. Binary stars that orbit around each other are quite common. Moreover, such systems are even found near the supermassive black hole at the center of the Milky Way – where gravity would tear them apart.
Some scientists believe that all stars first form in pairs. This raises the question: Was the Sun previously part of a binary system? Astronomer Gongjie Li of the Georgia Institute of Technology thinks it’s quite possible. If the Sun had a companion, the gravitational effects could disrupt the orbits of the planets, making Earth uninhabitable.
Hypothetical Nemesis
So far, a hypothetical companion of the Sun, Nemesis, has never been found despite numerous studies. But at the time of the Sun’s formation, about 4.6 billion years ago, the situation might have been different. Stars are formed by the collapse of giant clouds of gas and dust. This process often leads to the formation of double or multiple star systems.
In 2017, Sarah Sadavoy, an astrophysicist at Queen’s University in Canada, studied the Perseus molecular cloud, a region where binary stars are actively forming. Her work has shown that many stars begin their existence as pairs. However, some of them disintegrate within the first million years.
Search for evidence
The idea that the Sun may have had a companion finds confirmation in the Oort Cloud, a region of comets far beyond Pluto’s orbit. In 2020, astrophysicist Amir Siraj suggested that the structure of this cloud could be the result of a companion star. It is also hypothesized that such a star could facilitate the capture of additional planets, such as a hypothetical Ninth Planet.
However, Konstantin Batygin of the California Institute of Technology believes that the Oort Cloud can be explained without involving a companion. He suggests that the gravitational influence of other stars in the early cluster may have shaped its structure.
Another indication of the possible existence of a companion is the Sun’s tilt of 7° relative to the plane of the Solar System. This could be the result of the gravitational influence of another star early on.
Where did the Sun’s companion disappear to?
Even if the Sun had a companion, it would be hard to find it. This star is probably lost among billions of others in the Milky Way. In 2018, scientists discovered a twin star of the Sun with a similar chemical composition, but it is not proof of the existence of a companion.
The discovery of a binary companion to our Sun could shed light on the history of the formation of planetary systems. Today, astronomers are exploring exoplanet systems, many of which have binary stars. Some of them may even be similar to our fantasies of two suns in the sky.
Despite all this, modern science is only beginning to unravel the mysteries of the Sun’s early life. Perhaps the answer lies in distant regions of our Solar System, or even in stars that are forming right now.
Earlier we reported on how a comet and asteroid hybrid surprised astronomers.
According to BBC
