Disaster averted! Rogue star will not collide with us in 29,000 years
You can breathe easy and take the sticky tape off the windows because the solar system won't be hit by the rogue white dwarf WD 0810-353 in 29,000 years. ESO’s Very Large Telescope (VLT) shows that early calculations were a bit off.
Sometimes, you have to step back and look at the big picture. Unfortunately, the big picture can be pretty alarming. It's one thing to strive to achieve great things and to build a better world, but that comes off as a bit futile when you find out that a dirty big rogue star two-thirds the mass of the Sun could muck everything up in 29,000 years.
It makes you want to think twice about buying new carpet.
The latest scare came about in 2022 when astronomers Vadim Bobylev and Anisa Bajkova analyzed the data sent back by ESA's Gaia space observatory, which was launched in 2023. By studying the shift in the spectrum of the white dwarf star WD 0810-353 in the constellation of Puppis 36 light-years away, they calculated that the star was on a collision course with our solar system.
Since the rogue star will only pass within 31,000 AU (2.8 trillion miles, 4.6 trillion km) of the Sun, this doesn't seem much to lose sleep over, but that distance means it will pass through the Oort cloud, which is home to icy objects only kept in position by the tenuous grip of the distant Sun. When something like a rogue star passes through it, it can dislodge these objects and send them into the inner solar system.
Long story short: it could cause a rain of comets and asteroids in 29,000 years, like the one that may have killed off the dinosaurs.
However, that's not going to happen. Another team of scientists at the European Southern Observatory (ESO) used the facility's FOcal Reducer and low dispersion Spectrograph 2 (FORS2) installed on ESO’s VLT at the Paranal Observatory in the Atacama Desert in Chile.
Taking new spectra of the rogue star confirmed that the first calculations hadn't taken into account the powerful magnetic field of the star. Such fields can distort a spectrogram, spreading out the spectral lines and shifting them into new wavelengths. In the case of WD 0810-353, it made it look as if it was coming our way. By correcting the spectrum using a polarizing filter, a more accurate calculation was possible, which showed that the first estimate was more than a little bit off.
"We found that the approach speed measured by the Gaia project is incorrect, and the close encounter predicted between WD0810-353 and the Sun is actually not going to happen," says Stefano Bagnulo, an astronomer at Armagh and co-author of the study. "In fact, WD0810-353 may not even be moving towards the Sun at all."
In other words, the Earth is safe … for now.
The research was published in The Astrophysical Journal.