Rogue star rushing towards solar system is going to arrive sooner than we thought


According to new calculations, we may have a little less time to prepare for a star on its way to embrace the edges of our solar system.

Yeah. The dwarf star Gliese 710, which we have known for some time, could now arrive in 1.29 million years, instead of the 1.36 million years previously calculated.

Gliese 710 is what is classified as a rogue star – a star that has wandered through the galaxy, free from the gravitational chains that normally hold stars in position.

At a speed of 51,499 kilometers per hour (32,000 miles per hour), this is not fast enough to be considered a runaway star, but he still travels at a steady pace.

We knew the Gliese 710 was on a path that would bring it closer to the solar system since at least 1996, but it wasn’t until the end of 2016 that we had a good approximation on the timeline.

Based on first data release from ESA’s Gaia mission, astronomers Filip Berski and Piotr A. DybczyÅ„ski calculated that Gliese 710, then about 63.8 light-years (19.6 parsecs) away in the northern constellation Serpens, was to arrive in about 1.35 million years ago.

Astronomers Raul de la Fuente Marcos and Carlos de la Fuente Marcos of the University of Madrid verified this calculation based on the second, more accurate publication of Gaia data from the start of the year and confirmed it.

With one major difference: Using the new data, the time of arrival has been put forward by a few tens of thousands of years – and could come closer than expected to the solar system.

“Our results confirm, with errors, those of Berski & DybczyÅ„ski (2016), but suggest a closer flyby, both in terms of distance and time, from Gliese 710 to the solar system,” the researchers wrote in a new article.

It is important to note that the document was published prior to the final peer review. But with that caveat in mind, the fact that this is a follow-up analysis that confirms past data is an interesting next phase in the story.

Berski and Dybczyński discovered that Gliese 710 would enter the Oort cloud pass through the Sun a distance of approximately 13,365 astronomical units (each astronomical unit is the distance between the Earth and the Sun).

According to the new research, it will brush against us at a distance of 4,303 AU. It’s not really that close – it’s over 100 times the distance to Pluto, which orbits the Sun at an average of 39.5 AU. But it still has the potential to disrupt the solar system.

If humans are still on Earth at this time, we don’t have to worry about disruptions to our orbit. Gliese 710, which is only about 60% of the mass of the Sun, may have this effect only on the outer solar system, if at all, and should not affect anything below 40 AU.

What he could do, however, is behave like the proverbial fox among the chickens of the Oort Cloud. The Oort cloud is a theoretical sphere of icy planetesimals that would surround the solar system at distances between 200,000 and 50,000 AU.

If Gliese 710 enters the Oort Cloud, it could send these planetesimals into the solar system, resulting in comet showers.

But the solar system has already resisted close encounters with other stars, such as Gliese 208, which passed about 5 light years ago 500,000 years ago; and, more recently, 70,000 years ago, Scholz’s star, which crossed the Oort cloud.

Which, coincidentally, is when humanity was almost extinct for totally unrelated reasons. Probably.

You can read the new document on the preprint website arXiv.


Arline J. Mercier