HD 101584, a pair of dying stars sharing the same gaseous envelope. © ALMA (ESO / NAOJ / NRAO), Olofsson et al
The life and death cycle of stars is now well understood by the astrophysicist community. Some steps are however more obscure and must be better understood when we consider that all the complex elements in the universe, atoms heavier than hydrogen and helium, are synthesized by stars. The carbon in our bodies, the oxygen we breathe, the iron in our blood and our tools, the gold in our jewelry: all these materials come from the hearts of stars or their envelopes when they explode in supernovae.
A detailed understanding of each stage of stellar existence is therefore a major challenge in our quest for knowledge of nature and the universe. A particularly beautiful and mysterious phase has just been studied by finding binary stars, that is, the formation of a pair so close that they orbit in a common gas envelope, almost in a shroud. The pair HD 101584 looks like in visible light and surrounded by its nebula, all photographed by NASA’s Hubble Space Telescope.
The pair HD 101584 and its nebula were observed by Hubble. © NASA / ESA Hubble Space Telescope
Here’s another brilliant pair, including a white dwarf, responsible for the Sculptor Nebula.
Fleming 1, a nebula shaped like two suns in very close orbits, including a white dwarf. © ESO
Still captured by Hubble, NGC 2346 is another nebula formed in very tight orbits by these pairs of stars in the Unicorn constellation.
NGC 2346, the nebula is sculpted by the very close orbits of two stars, including a dwarf star. © NASA/ESA Hubble Space Telescope
These pairs of stars will become explosive “catastrophic mutations”!
This type of sun has charm. When its still “living” component, that is, fusing atoms in its core, will reach its final stage, that of a red giant star, its diameter will be greater than a factor of 100, or even 1000. will go However, the two stars remain close enough to each other that the smaller – and denser – periodically rips matter from its “diffuse” – therefore less dense – larger companion. When this material falls, it will cause a thermonuclear explosion! This is the next step in the evolution of these star pairs, called “cataclysmic variables”.
And although so-called binary stars are very common in the universe, it is not so easy to share these particular pairs in a common envelope. Here, scientists were able to identify 52 serious candidates spread across 38 open star clusters in the Milky Way. Among these open clusters, the most famous is the Pleiades, located 444 light-years from Earth.
The famous Pleiades open cluster. © Mount Palomar Observatory
Having isolated candidates for this stage of catastrophic mutation, both scientifically beautiful and exciting, will allow important theoretical advances, according to Stephanie Grondin, lead author of the study: “This observational model is an important first step in allowing us to follow the entire life cycles of binaries. And, hopefully, it will allow us to better constrain the most mysterious phase of stellar evolution.”
The research was made possible thanks to the automatic learning of artificial intelligence.
Joshua Spiegel, co-author of the study, explains that artificial intelligence Also enables automatic search on hundreds of clusters. A task that would have been impossible if we had tried to identify these systems manually.
This new model allows us to build on our knowledge of supernova 1a (a type in which binary systems have at least one white dwarf, the second Sun can be any type), nucleosynthesis and gravitational waves. will give
Sources:
Phys.org
The Astrophysical Journal
