Researchers have discovered a small star, it is the size of the moon. Scientists suggest that this is a white dwarf – a very heavy core of a burned-out star with a strong magnetic field and high density of matter.
Scientists have found ZTF J1901+1458, one of the smallest white dwarf stars that astronomers have ever discovered. The star’s dying husk, similar to the sun, was spotted by ground-based and space telescopes only 133 light-years away.
In a study published in the journal Nature, scientists detailed the discovery and characteristics of ZTF J1901+1458, so named because it was spotted by the Zwicky Transient Facility, California’s Palomar Observatory, which searches for any object in space with sudden changes in brightness.
White dwarfs form when stars that are eight times the mass of our Sun or less reach the end of their lives. When they run out of fuel, they begin to disintegrate, but, paradoxically, as a result of this destruction, the star swells to monstrous proportions and becomes a red giant.
During this process, the star cools down a little, its core contracts, which releases a huge amount of energy, and the star becomes larger again. However, it begins to lose its outer layers and leaves behind only an extremely dense core – this is the white dwarf.
This is what the research team saw – the shell of a burned-out star. To better understand its characteristics, they used data collected by the European Space Agency’s Gaia satellite, Hawaii’s Keck Observatory, and NASA’s Swift Observatory.
The team believes that this white dwarf was originally two stars. They both evolved to become white dwarfs, and then finally merged and formed a new, much more massive star.