An unseen white dwarf discovered. It is small, but cruelly material
Viewed on terrestrial scales, there are many bizarre objects in the universe that are difficult to imagine. They also include the newly discovered white dwarf.
Astronomers found a white dwarf torso of the star 134 light-years away, 1270 trillion kilometers, using the Palomar Observatory in California. They named it ZTF J190132.9 + 145808.7.
This white dwarf is the smallest and most massive object of its kind ever discovered.
ZTF J190132.9 + 145808.7 measures an average of 4300 kilometers, which is slightly more than the average of our Moon (3500 kilometers). But it is 1.35 times the weight of the Sun.
It can therefore be simply compared to the Sun crammed into the Moon. And this “compressed Sun” also rotates furiously – it rotates around its axis in just seven minutes.
When the dwarves unite…
White dwarfs such as ZTF J190132.9 + 145808.7 are collapsed remnants of stars. The Sun will end up like a white dwarf one day.
In five billion years, our life-saving star will run out of fuel for thermonuclear fusion. Its envelope will expand and cool. The sun will take the form of a red giant and engulf nearby planets, probably Earth.
Eventually, it blows away its outer layers and shrinks into a compact white dwarf consisting mainly of carbon and oxygen. And like any white dwarf, it will radiate the energy accumulated during its active star life and cool.
However, the smallest and most massive white dwarf ZTF J190132.9 + 145808.7 has a different history. Astronomers who discovered and described it in a study published in the journal Nature assume that it originated from two dwarfs that rotated around each other until they merged.
A combination of two white dwarfs, from which a new white dwarf of extreme weight emerges. | source:
Profimedia
If the critical mass were exceeded in such a case, it would end in an explosion – a supernova – and a neutron star would be born. Or a black hole. In this case, however, astronomers found that about 100 million years ago, an extremely massive white dwarf formed.
The result of the connection is a wild rotation and an extremely strong magnetic field of the dwarf. Scientists have found that it is almost a billion times stronger than the Sun’s magnetic field.
“This white dwarf raises many questions that we should look for answers to. For example, ‘what is the rate of white dwarf merging in the galaxy?’, According to a study led by Ilaria Caiazz of the Caltech Institute of Technology in California.
Researchers speculate that the dwarf is massive enough to collapse into a neutron star once, an object made up of neutrons held together by gravity. If their hypothesis were true, then at least some of the neutron stars would form in this way.
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