Dying stars may also continue to produce planets, according to research by international scientists led by KU Leuven. Until now, it was only known that planets form around young stars. This discovery could lead to a complete overhaul of current theories about planet formation.
The Earth formed very quickly, less than ten million years after the sun formed. The other planets in our solar system formed relatively quickly. So the planets were supposed to consist of “young” stars. It now appears that dying stars can also give rise to planets.
To do this, the researchers studied the so-called evolving binary stars in our Milky Way galaxy. Evolving binary stars are two stars that orbit a common center of gravity. One of the two stars is a star at the end of his life. When a single star dies, it ejects the outer portion of its atmosphere into space and then slowly dies. However, in binary stars, the gravity of the living star pushes the material ejected from the dying star into a flat rotating disk around the two.
These discs are also similar to those that astronomers observe around young stars elsewhere in the Milky Way. The researchers also found signs of planet formation in these flat disks of binary stars. Scientists examined 85 pairs of binary stars and found a large “cavity” of 10 percent, which means that a large hole can be seen in the flat disk.
“It indicates that something is floating in there and has collected all the matter at the apex of the cavity,” explains astronomer Jacques Kluska (KU Leuven). “It seems that this is the work of a planet.” The researchers also saw that some elements, such as iron, were only present in a limited range.
“This indicates that the particles of matter rich in these elements was a planet prospecting.” This discovery, says Kluska, is unexpected. “We have taken inventory of the advanced binary stars in our Milky Way galaxy.
special hypothesis
Remarkably, we can formulate this hypothesis. This means that current theories about planet formation must be modified. “The astronomers want to verify their hypothesis themselves. To do this, they will study the ten binary star pairs in which the disk of matter shows a large cavity, using the large telescopes from the European Southern Observatory in Chile.
The study was published in the scientific journal Astronomy and Astrophysics.
The Earth formed very quickly, less than ten million years after the sun formed. The other planets in our solar system formed relatively quickly. So the planets were supposed to consist of “young” stars. It now appears that dying stars can also give rise to planets. To do this, the researchers studied the so-called evolving binary stars in our Milky Way galaxy. Evolving binary stars are two stars that orbit a common center of gravity. One of the two stars is a star at the end of his life. When a single star dies, it ejects the outer portion of its atmosphere into space and then slowly dies. However, in binary stars, the gravity of the living star pushes the material ejected from the dying star into a flat rotating disk around the two. These discs are also similar to those that astronomers observe around young stars elsewhere in the Milky Way. The researchers also found signs of planet formation in these flat disks of binary stars. Scientists examined 85 pairs of binary stars and found a large “cavity” of 10 percent, which means that a large hole can be seen in the flat disk. “It indicates that something is floating in there and has collected all the matter at the apex of the cavity,” explains astronomer Jacques Kluska (KU Leuven). “It seems that this is the work of a planet.” The researchers also saw that some elements, such as iron, were only present in a limited range. “This indicates that the particles of matter rich in these elements was a planet prospecting.” This discovery, says Kluska, is unexpected. “We have carried out an inventory of evolving binary stars in our Milky Way. Being able to formulate this hypothesis is extraordinary. This means that current theories about planet formation must be modified.” Astronomers want to verify their hypotheses themselves. To do this, they will study dozens of binary star pairs in which the disk of matter shows a large cavity, with the large telescopes of the European Southern Observatory in Chile. The study was published in the scientific journal Astronomy & Astrophysics.
