The image was a discovery. 120 individual exposures had to be combined to get a total exposure time of 20 hours. The images were taken in Brazil. Credit: Maicon Germiniani.
Scientists have succeeded in confirmation of a shell of a common-envelope system, the phase of the common envelope of a star system.
Normal stars inflate into red giant stars at the end of their lives. The evolution of stars at the end of their lives is affected by the large number of stars in a single star. The inflating outer part of a star becomes a common envelope around both stars in close systems. The core of the two stars are almost completely undisturbed and follow their evolution like single stars. The results of the research have been published.
The discovery was made thanks to amateur astronomer.
Many stellar systems are remnants of that evolution. Their physical and chemical properties are used to identify them. There are systems that are about to develop a common envelope that have already been discovered. The fully developed envelope of a CE has not been observed so far.
The evolution of stars in their final phase is important to our understanding. Kimeswenger says that they help us to understand how they enrich the space with heavy elements, which is important for the evolution of planetary systems. He says that they are too large for a field of view of modern telescopes and that they are very faint. Their lifetime is shorter when considered in the time scales. It is only a few hundred thousand years.
A group of German and French amateur astronomer found a fragment of a nebula on photographic plates from the 1980s after searching historical images for unknown objects in the now-digitized archives.
International cooperation solved a puzzle.
The Department for Astro and Particle Physics at the University of Innsbruck was contacted by the group after they found out about it. The researchers in Innsbruck were able to rule out the discovery of a planetary nebula caused by the remnants of dying stars by combining observations from the past 20 years with data from four different space satellites. The extent of the nebula became apparent with the help of telescopes. Scientists in the U.S. finally completed these observations. The main cloud is more than 1 million times larger than the distance of the earth to the sun and more than the distance of our sun to its nearest neighbor. There are fragments as large as 39 light-years apart. Kimeswenger says that the object lies slightly above the Milky Way and that it was able to grow undisturbed by other clouds in the surrounding gas.
A model of a new class of planets.
The model of the object was created by combining all this information. There is a white dwarf star and a normal star in a close system. Both of them were in motion in 8 hours and 2 minutes. Due to the small distance, the companion star, with a temperature of only 4,700 degrees, is strongly heated at the side facing the white dwarf, which leads to extreme phenomena in the spectrum of the star and to very regular variations in brightness. The outer material of the white dwarf is around the stars. The material was ejected from space 500,000 years ago, at just over one solar mass.
It is possible that this system is related to a nova observation made by Korean and Chinese astronomer in 1086. The positions of the historical observations match those of our object.
More information about YY Hya and its environment, Astronomy & Astrophysics. There is a DOI: 10.1051/0004-6361/202039787.
The journal has information about astronomy and astrophysics.
The evidence of a new class of Galactic nebulae was retrieved on December 21st, 2021.
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