A white dwarf star headed towards the solar system: it looks like a science fiction film. A new study shows what is true in the scenario.
Armagh – Last year, a research team discovered that a white dwarf star called WD 0810-353 was heading directly towards our solar system. What seems scary is apparently no cause for alarm: Another research team observed the star and found that it’s not even clear whether it’s actually moving in our direction.
But let’s start from the beginning: after the first research group evaluated the data from the “Gaia” space telescope last year, it came to the conclusion that the white dwarf will be 31,000 astronomical units from our solar system (about 4, 65 billion kilometers) in about 29,000 years is approaching. For comparison, the closest star to our solar system is Proxima Centauri, at a distance of about 4.2 light years (equivalent to 39.7 trillion kilometers).
After all, the white dwarf star apparently does not come close to the Sun
For humans, this is a distant moment in the future and a distance that is difficult to imagine, but in astronomical perspective it is only a moment and a stone’s throw away. For comparison: our solar system formed about 4.6 billion years ago. And only in another five billion years will the Sun expand into a red giant star and seal the end of the Earth.
A second research group led by astronomer Stefano Bagnulo (Armagh Observatory & Planetarium) now gives the green light to the white dwarf star: “We have discovered that the approach speed measured by the ‘Gaia’ project is incorrect and the predicted close encounter between WD0810-353 is incorrect and the sun will actually not appear,” says the co-author of the new study, published in Astrophysics Journal has been published. “In fact, WD0810-353 may not move toward the Sun at all.”
The white dwarf WD 0810-353 has a strong magnetic field
Apparently the fact that the white dwarf has a strong magnetic field has been overlooked. “In astronomy, magnetic fields are crucial to understanding many physical aspects of a star, and ignoring them can lead to misinterpretations of physical phenomena,” astronomer Eva Villaver explains in a note.
If the star were actually within 31,000 astronomical units (AU) of the solar system, it would be in the middle of the Oort cloud. This is a region of icy debris surrounding the solar system at a distance between 2,000 and 100,000 AU. Long-period comets that take more than 200 years to orbit the sun probably originate from the Oort cloud.
The star will not fly through the Oort cloud: no danger to the Earth
The problem is that if a star passes through the Oort cloud, it could change the orbits of the icy debris and, in the worst case, send chunks of rock on a collision course with Earth or other planets in the solar system. But that probably won’t happen for 29,000 years, the new study shows. Researcher Bagnulo is relieved: “This is one less cosmic danger we have to worry about!” (form)