The messy death of a star, as observed by James Webb

The scientific community reconstructed the death of the star that formed the Southern Ring Nebula NGC 3132 , one of the first protagonists of the images by James Webb .


A team of nearly 70 astronomers from 66 organizations in Europe, the Americas and Asia have used images from the James Webb Space Telescope to reconstruct the messy death of a star .

About 2,500 years ago, a star ejected most of its gas, forming the beautiful Southern Ring Nebula, NGC 3132 , chosen as one of the first five Webb imaging packages.

“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 and left behind a dense remnant white dwarf star, with about half the mass of the Sun, but about the size of the Earth,” says Professor Orsola De Marco, lead author of the paper, from Macquarie University’s Center for Astronomy, Astrophysics and Astrophotonics Research.

“We were surprised to find evidence of two or three companion stars that probably hastened their death, as well as one more ‘innocent bystander’ star that got caught up in the interaction,” he explains.

so the star died 

The study, which is published in Nature Astronomy , was based on the James Webb images supplemented with data from ESO’s Very Large Telescope in Chile, the San Pedro de Mártir Telescope in Mexico, the Gaia Space Telescope and the Hubble Space Telescope.

It paves the way for future James Webb observations of nebulae , providing insights into fundamental astrophysical processes, including colliding winds and binary star interactions , with implications for supernovae and gravitational wave systems.

The astronomers in the study met online and developed theories and models around the mid-infrared image to reconstruct how the star had died .

At the center of the nebula shines an ultrahot central star , a white dwarf that has consumed its hydrogen. “This star is now small and hot, but it is surrounded by cool dust,” said Joel Kastner, another member of the team, from the Rochester Institute of Technology. “We think that all the gas and dust we see being spewed everywhere must have come from that star , but was spewed in very specific directions by companion stars .”

There are also a series of spiral structures coming out of the center. These concentric arcs would be created when a companion orbits the central star while it is losing mass. Another companion is further away and is also visible in the image.

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.

“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 you can see in the image. Once we saw the jets, we knew there was to be 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 far away, if this is the case there are four or even five objects involved in this messy death DeMarco explains. (Europe Press)