Las first images revealed by him james webb space telescope They amazed the world: stellar nurseries, exotic and inflated exoplanets or dying stars showed that the brand new observatory had arrived to show us a new vision of the universe. But it’s not just about getting ‘pretty’ images. The main objective is to do science and understand many astronomical phenomena that we still do not fully understand.
This is precisely what happened with one of the formations that we were able to see from a different ‘look’ thanks to the Webb. The southern rings nebula, 2,500 light-years from us, loomed large, revealing two stars close together at its center: the dimmer red one is a dying star that has been emitting rings of gas and dust in all directions for millions of years. At her side, a lighter companion seemed to be responsible for these random patterns for which she also received the name of Eightburst Nebula.
However, a team made up of 70 astronomers from 66 organizations in Europe, America and Asia have reconstructed what the explosion of this star was like 2,500 years ago and how possibly at least three other companions were involved in the process, which would explain the erratic pattern. from the stardust around it. The results have just been published in the journal ‘Nature Astronomy‘.
Filaments that reveal details
“It was almost three times the size of our Sun, but much younger, about 500 million years old. It created veils of gas that expanded from the ejection site, causing the white dwarf to be as dense as half the mass of the Sun, but compressed to the size of Earth,” he explains. Orsola DeMarco, from the Research Center for Astronomy, Astrophysics and Astrophotonics at Macquarie University, and lead author of the study. “We were surprised to find evidence for the existence of two or three companion stars that probably hastened the death of the parent, as well as one more ‘innocent bystander’ who got caught up in the interaction,” she says.
The spark to start the study began with the revelation of the images. They gathered online and, in addition, completed the data with information collected by ESO’s Very Large Telescope in Chile; the San Pedro de Mártir Telescope, in Mexico; the Gaia Space Telescope; and the Hubble Space Telescope. Thus, they began to develop theories and models to try to discover what the death of that star had really been like.
By examining the bright, straight lines that pierce the rings of gas and dust around the edges of the South Ring Nebula, the authors realized that these ‘rays’ appear to emanate from one or both of the central stars, marking where the light flows through holes in the nebula. By projecting the straight lines, the researchers conclude that they may have been ‘fired’ hundreds of years earlier and at a faster rate than those that appear thicker and curvier. It is possible that the second set is a mix of material that has been slowed down, creating less linear forms.
The authors explain that, initially, the system had a red giant something bigger than our Sun, which imploded when it ran out of hydrogen, swelling up. In this process, it shed its outer layers, expelling the surrounding material that forms the nebula.
Looking closely at the near- and mid-infrared images, they observed bright, straight streaks crisscrossing rings of gas and dust around the edges of the South Ring Nebula. To see where they came from – and as if they were stellar detectives – they projected the lines into the formation.
Indeed, these rays appeared to emanate from one or both of the central stars, very dense white dwarfs that were created after the explosion. The researchers have the theory that these rays were ‘fired’ hundreds of years earlier (and at a much faster speed) years before the rest of the material that created this kind of irregular ‘sphere’, which would have slowed down, forming this curious arrangement.
reconstruction of a death
The authors looked at the center and observed that the two stars that are perfectly captured in the images are, in effect, two white dwarfs; and although it seems that one is bigger than the other, They are the same size: the difference in brightness is that the reddest one is covered by a lot of cold dust that forms a disk.
However, the existence of these two white dwarfs did not explain the irregular pattern of the nebula’s disks. By looking at a three-dimensional reconstruction of the data, the team also saw pairs of bulges that can occur when astronomical objects eject matter in a jet. These are irregular and shoot out in different directions, possibly implying a triple star interaction at the center. That is, at least there was one more star than thought. But neither did the arrangement of dust and gas fit well with a triple system.
“We first inferred the presence of a close companion due to the dust disk around the central star, the additional companion that created the arcs, and the super far companion that can be seen in the image,” says De Marco. Once we saw the jets, we knew there was another star or even two involved in the center, so we think there are one or two very close companions, an additional one in the middle distance, and one very distant one, if this is the case.there are four or even five objects involved in this messy death«.
How did five stars create the Southern Ring Nebula? The first box shows a larger field with stars 1, 2 and 5, the last of which orbits Star 1 much more closely than Star 2. The second box zooms very close to the scene, showing the other two stars (3 and 4); star 3 is emitting jets of particles, as can be seen in the image. The third inset shows star 1 expanding (getting bigger) as it ages. Stars 3 and 4 are emitting jets of particles. In the fourth inset we zoom out to see how light and stellar winds are carving a bubble-like cavity. Star 1 is surrounded by a disk of dust. In the fifth inset, Star 5 interacts with the expelled gas and dust, generating the large ring system seen in the outer nebula. The sixth box portrays the scene as we see it today
So, the sequence would have been like this, according to the authors: at the beginning, there would be three very close stars (1, 3 and 4 in the top reconstruction). Another would be relatively close to this group (5) and there would be a fifth further away from the rest (2).
The main star (1) would have expanded as it aged, while its closest companions (3 and 4) emitted jets of particles. The stellar winds and the interaction with all the stars in the system would have created the particular halo of dust and gas that can be seen, they are carving a cavity similar to a bubble. The closest stars of the main one would be ‘hidden’ by the disk of cold dust that surrounds the protagonist.
This is one more example of the power of James Webbthe most powerful space telescope sent into space to date and which promises to reveal many mysteries still hidden in the universe.