Astronomers discover record-breaking moon-sized star
According to a new study published in the journal Nature, astronomers have discovered a "special" star with a mass greater than the mass of the Sun, but similar in size to the Moon. Such stars form in a system of two less massive white dwarf stars when they collide and merge into one.
At the end of their lives, most stars turn into white dwarfs, which are actually the "smoldering" remains of stars. They are some of the densest objects in the universe, along with black holes and neutron stars. In about 5 billion years, our Sun will become a red giant, after which it will suffer the same fate.
The highly magnetized dead star, named ZTF J1901 + 1458, is relatively close to Earth - only 130 light-years away. It was discovered by the Zwicky Center for Transient Phenomena (ZTF) at the Palomar Observatory in San Diego, California.
When the two white dwarfs merged, they formed a new star about 1.35 times more massive than our Sun. It is the most massive star of its type ever discovered. If the mass of one of the two stars were slightly greater, the merger would lead to a violent explosion called a supernova.
ZTF J1901 + 1458 has a powerful magnetic field, nearly 1 billion times stronger than that of the Sun. The star rotates very quickly, completing one complete revolution in just seven minutes. In comparison, the Sun takes about 27 days to complete one revolution. With a diameter of only 4,296 kilometers, it is the smallest known white dwarf star in the universe. For comparison, the Moon is 3,498 kilometers across.
Illustrations: Guiseppe parisi
