The “twins” Alpha Centauri A and B
“Binary stars” are very common, but the Sun remains alone. For now. The lost companion seems to be out there, waiting to be discovered.
The closest star to our Sun, Proxima Centauri, is 4.2 light-years away, so remote that even the fastest spacecraft ever built would take more than 7,000 years to get there, explains .
It’s a shame for the Sun, which is alone, without any stars keeping him company.
As “binary stars” are quite common, They were even found in a place where they were not expected to exist, because they would separate due to gravity: close to the supermassive black hole located in the heart of the Milky Way. If most stars have a twin, could the sun have one too?
Fortunately for us, our Sun doesn’t currently have a friend. If I hadthe gravitational pull of a solar sibling could have perturbed Earth’s orbit and other planets, condemning the planet to oscillate between extreme heat and cold, in a way that could be too inhospitable for life to exist.
The Sun was formed 4.6 billion years ago, which makes it possible that, in the meantime, its brother was lost. But astronomers are trying to find it.
Em 2017, Sarah Sadavoyastrophysics from Queen’s University, not Canada, which all stars could form in pairs or in multi-star systems.
“You get small density peaks inside these cocoons, which can collapse and form multiple stars, which we call fragmentation process“, says Sadavoy. “If they are too far away from each other, they may never interact. But if they are much closergravity has the ability to hold them together“.
Em 2020, Amir Sirajan astrophysicist at Harvard University in the USA, suggested that a region of icy comets that surrounds our Solar System far beyond Pluto, the could contain an imprint of this companion star.
“It is difficult to produce as many objects in the confines of the Oort Cloud as those we see without a companion star”, argues the astronomer.
It may be possible to confirm whether this idea is true with a new telescope in Chile, called , which is expected to be activated next year and carry out the most detailed study of the sky ever in the next 10 years.
“When Vera Rubin goes live and starts mapping the structure of the Oort Cloud in more detail, we will be able to see if there is a clear fingerprint of the binary companion,” says the American scientist Konstantin Batygin.
Another possible signature of the impact of a binary companion is the fact that our Sun is about seven degrees relative to the plane of the Solar System. A possible explanation for this fact is the gravitational pull from another star, which knocked the Sun out of balance. “I think the most natural explanation is the presence of a companion star at an early stage,” says Batygin.
It is therefore likely that any twins of the sun are still “lost among the sea of stars we see in the night sky”, says Sadavoy.
Stars born in the same region of space as the Sun may have a similar composition, because they were forged from the Sun. same mixture of gases and dustwhich makes them a kind of twins.
In 2018, scientists identified one of these “twin” stars of the Sunwith a similar size and chemical composition, located less than 200 light years away.
Whether it exists or not, so far, the Sun’s twin hasn’t done any damage yet — we’re still here to look for it. “It could be on the other side of the galaxy and we wouldn’t know it,” says Sadavoy. “It could be anywhere.”
