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A white dwarf star heading towards the solar system: that sounds like a science fiction movie. A new study shows what is true in this scenario.
Armagh – Last year, a research team discovered that a white dwarf star called WD 0810-353 was heading directly toward our solar system. What sounds scary is apparently no cause for alarm: Another research team looked at the star and found that it’s not even clear if it’s actually moving in our direction.
But let’s start at the beginning: after last year the first research team evaluated the data from the “Gaia” space telescope, it came to the conclusion that the white dwarf will be 31,000 astronomical units from our solar system (about 4.65 billion of 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).
White dwarf star apparently not getting close to the Sun after all
For humans, this is a time far in the future and a distance difficult to imagine, but from an astronomical perspective it is just 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 team led by astronomer Stefano Bagnulo (Armagh Observatory and Planetarium) now gives the go-ahead regarding the white dwarf star: “We have discovered that the approach speed measured by the ‘Gaia’ project is incorrect and the encounter predicted close proximity between WD0810-353 is incorrect and the sun will not actually appear,” says the co-author of the new study, published in the journal Astrophysical diary Has been published. “In fact, WD0810-353 may not be moving toward the Sun at all.”
White dwarf WD 0810-353 has a strong magnetic field
The fact that the white dwarf has a strong magnetic field was apparently overlooked. “In astronomy, magnetic fields are crucial to understanding many physical aspects of a star, and ignoring them can lead to erroneous interpretations of physical phenomena,” explains astronomer Eva Villaver in a statement.
If the star really came 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 of approximately 2,000 to 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 pass through the Oort cloud: there is no danger to Earth
The problem is that if a star passes through the Oort cloud, it could change the orbits of the icy remains 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 another 29,000 years, the new study shows. Researcher Bagnulo is relieved: “That’s one less cosmic danger we have to worry about!” (eyelash)