2023-10-14 17:06:15
Stars with a mass similar to our Sun end their lives as white dwarfs. Just before, they lose part of their mass. How much ? Astronomers provide an answer thanks to a unique study of a white dwarf at the center of a planetary nebula.
This will also interest you
[EN VIDÉO] The life and death of a star and its planets This video with animations retraces the major stages of the birth and…
What astronomers call open clusters, there are around a thousand in our Milky Way. Each contains several thousand stars that were born at the same time, but which, depending on their mass, may be in different stages of their lives today. This is why researchers are so interested in it. Because open clusters constitute a kind of laboratory which allows them to test their theories on stellar evolution.
Stars evolve according to their mass
Among the questions that remain unanswered is how much mass a star loses. Especially towards the end of his life. Astronomers estimate that stars like our Sun, for example, lose a little less than half of their mass when they evolve into white dwarfs. It’s not nothing. Although more massive stars are known to lose even more.
However, never before has a very young white dwarf been studied. These stars evolve in the heart of planetary nebulae which were formed from the gases ejected by the dying star. But until now, these white dwarfs remained too faint and too distant for astronomers to be able to dissect them.
A look at a white dwarf at the center of a planetary nebula
However, this is what researchers from the University of Tübingen (Germany) managed to do thanks to one of the largest telescopes in the world, the Large Canary Islands Telescope or GranTeCan. In the newspaper Astronomy & Astrophysics, they tell how they observed and studied the spectrum of the central star of a planetary nebula in the cluster M37. A star now weighing 0.85 solar masses which would therefore have lost 70% of its mass during its life. Astronomers also note that the star no longer had hydrogen on its surface. Enough to consider the occurrence of an unusual event in its recent past, such as a brief burst of nuclear fusion.
1697348395
#destiny #Sun #revealed #white #dwarf
