More than 300 astronomical objects have been thrown off their normal orbit by the gravitational pull of a visiting star which sped through the solar system some 70,000 years ago.
In 2015, calculations of the red dwarf's velocity and trajectory revealed that it passed a cloud of comets known as the Oort Cloud before approaching the sun.
Nicknamed as Scholz's Star, it came as close as 0.8 light-years away from the larger star, posting the closest flyby distance ever made by another stellar object in history.
In contrast, the closest neighboring star Proxima Centauri lies five times farther, at approximately 4.2 light- years beyond the solar system.
More recently, more details of the phenomenon have been unveiled as a research team investigated how it has affected the comets and asteroids that were on the star's path.
Scholz's Star Caused Hyperbolic Orbits
Hyperbolic objects have long baffled astronomers with their strange movement. Instead of traveling in an elliptical motion, they move in an irregular V-shaped manner.
After analyzing 339 of these objects, the team led by Carlos de la Fuente Marcos of Universidad Complutense de Madrid discovered that they were once a part of the Oort Cloud and were only knocked away as the prehistoric star passed through the cluster of comets.
Another possible culprit is the Milky Way galaxy's disk. However, the over-density of hyperbolic objects near Gemini suggests they had an encounter with the flyby.
"It could be a coincidence, but it is unlikely that both location and time are compatible," says de la Fuente Marcos in a statement, clarifying that not all hyperbolic objects in the solar system have been disturbed during the phenomenon.
Only those that were on the path of Scholz's Star have been affected. For instance, the asteroid Oumuamua has no involvement with the flyby as it's found in the constellation of Lyra, which is more distant than Gemini.
Detailed results, as well as the eight other interstellar comets identified by the team, are all included in a paper published Feb. 6 on the Monthly Notices of the Royal Astronomical Society.
Flybys Can Also Produce In Comet Showers
As part of the earlier study, another team studied 10,000 simulations of the red dwarf moving past the Oort Cloud. They wanted to explore the potential results of such a phenomenon.
In 98 percent of these simulations, the star only grazed the outer portion of the cloud. However, there was one that showed the star entering the inner portion of the cloud and then producing a comet shower.
To date, Scholz's Star still has no contender. The Rogue Star or HIP 85605, which is expected to flyby in 240,000 to 470,000 years from now, presents no match for the existing record.
