Arquivo para November 11th, 2021

The evolution of stars and white dwarfs

11 Nov

The evolution of a star like the Sun goes from a giant to a supergiant phase and ejects a planetary nebula and then transforms into a white dwarf when it is losing its energy and brightness.

The basis of stellar evolution calculations is called Hydrostatic Equilibrium whereby the pressure of the gas counteracts gravity in most of the lives of stars, since if there is no such dynamic equilibrium or time it collapses, so stars have nuclear reactions at some stage in their evolution, the ones that don’t have are brown dwarfs.

Using the ALMA radio observatory in Chile, which study a dozen red giants, the evolutionary stage at which stars approach death, they release an enormous amount of energy, producing a constant stellar wind, ie, ejecting a stream. of particles that throws the mass of the star itself in all directions, and these are the bases of its spectacular images.

If they were solitary nebulae, they would only have concentric shapes, but the presence of other companion stars and even planets that orbit the red giants, the influence of their fields ends up forming other images, influenced by the surrounding objects, giving specific configurations and colors.

One of the project scientists Carl Gottlieb, co-author of the study “(Sub)stellar companions shape the winds of stars evolved” said: “We now have an unprecedented view of how stars like our Sun will evolve during the last stages of its evolution”, this is of course on a scale of millions and even billions of years.

Palaeontologist and theologian Teilhard Chardin said that on the scale of the Cosmos: “only the fantastic has the condition to be true, planetary nebulae form incredible cosmic images that look more like divine paintings and are formed around a star that has reached the giant stage red, and recently scientists discovered why their shapes are unique.