In the early days of the Solar System, the Sun may have had a companion star, scientists say, making it part of a binary system like many others in the Milky Way galaxy. ... We know the Oort Cloud

is out there because periodically these objects are perturbed from their orbits and fall into the inner Solar System as comets.

Why is the sun not a binary star?

For some time now, astronomers have known that the majority of systems in our galaxy consist of binary pairs rather than individual stars. What's more, in recent decades, research has revealed that stars like our Sun are actually born in clusters within solar nebulas.

Was the sun a twin?

Now, a pair of researchers has offered a new take on this far-out mystery: Our sun has a long-lost twin. ... Unlike the planets and asteroids of the inner solar system, which lie on a single flat disk around the sun, it forms a hollow sphere of debris encircling the solar system in every direction.