Webb Telescope Reveals Bright Stellar Crime Scene

Two images of the South Ring Nebula taken by the Webb Telescope.

This milky, bloody Webb boon shows how gas is distributed in the South Ring Nebula.

2,500 years ago, one of the most beautiful features of space was born: the South Ring Nebula. The nebula was vividly photographed by the Webb Space Telescope earlier this year, and astronomers now think they know exactly how a star’s violent explosion happened, leaving the elegant nebula in its wake .

The star that carried the nebula was about three times the size of the Sun and 500 million years old. It’s pretty young, in stellar terms; our Sun is about 4.6 billion years old and expected to live another 5 billion years.

Around 2,500 years ago, Confucius and the Buddha were still alive. The Peloponnesian Wars were about to begin. And somewhere in those intervening years, a star 2,000 light-years away expired, blasting gas outward from a newly formed white dwarf.

The star in the Southern Ring Nebula is not yet dead, but its expulsion of gas is a major turning point in the star’s lifespan. White dwarfs are the stellar endgame; they form when stars have exhausted their nuclear energy and begin their slow cooling.

Thanks to images from the Webb Space Telescope and the research team’s clever calculations and mathematical modeling, the moments before the stellar light show of the South Ring Nebula can now be examined in detail.

Different Webb filters highlight various aspects of a light source, which is why some parts of the nebula may appear pearlescent or a translucent red while others appear blue or orange, depending on the image. Webb image processors choose to highlight different aspects of objects in order to emphasize various elements – hot gases, for example, or stellar factories within larger systems.

A team of 70 astronomers worked together to determine that up to five stars (only two of which are now visible) may have been involved in the stellar disappearance. Their investigation into the death of the star is published today in Nature Astronomy.

A representative color image of the South Ring Nebula from the Webb Telescope.

“We were surprised to find evidence of two or three companion stars that likely hastened its death, as well as another ‘innocent bystander’ star that got caught up in the interaction,” said Orsola De Marco, an astronomer at Macquarie University and responsible for the study. lead author, in an academic statement.

The team’s play-by-play on the origins of the nebula was possible thanks to very precise measurements of the brightest star (the star among stars, if you will) in the Webb image. The Webb data allowed the researchers to accurately measure its mass and the stage of its own life, allowing them to derive the mass of the faint central star before it lost its material and collapsed. creates the colored nebula.

Webb imaged the South Ring with two instruments, NIRcam and MIRI. The Webb images were supplemented with data from the European Southern Observatory’s Very Large Telescope, the San Pedro de Mártir Telescope, and NASA’s Gaia and Hubble Space Telescopes.

Only two of the stars thought to be involved in this cosmic rage are visible in Webb’s representative color snapshot of the nebula, taken with NIRcam. The bright star in the center of the nebula is associated with the one that ejected so much material that it became a white dwarf. This shrunken (and exhausted) star lies faintly along the 8-hour diffraction peak of the bright central star in the image above.

Astronomers believe that at least one star interacted with the fainter star (star 1 in the timeline shown below) as the latter swelled, preparing to expel its gas and become a white dwarf.

According to the team, this mysterious star (Star 3) spewed out jets of material as it interacted with the dying star and covered the faint star in dust before merging with the dwarf. Star 2 in the illustration is now the bright spot in the center of the nebula – a relatively solid figure, given its lack of explosive activity or gaseous releases.

Six panels showing the relative proximities of stars and how they interact, giving rise to the nebula.

A play-by-play of the creation of Nebula.

Another star (or “party girl,” in the Space Telescope Science Institute’s analogy of an astrophysical party gone wrong) kicked up gas and dust released by its predecessor, causing wavy ripples in the material. Then another star (star 5 in the panels above) circled the light show and produced the ring system encircling the nebula.

According to the researchers’ calculations, you can consider the white dwarf near the nebula’s core to be the host of the party that raged too much and passed out long before the party was over. But the star kept everyone having a good time while she was up for it, and that’s what kept the party going.

“We believe that all this gas and dust that we see thrown around must have come from this one star, but it was thrown in very specific directions by companion stars,” said Joel Kastner, an astrophysicist at the Rochester Institute of Technology, in an StScI version.

The researchers believe that the same methods that uncovered the specifics of the South Ring Nebula’s birth could help unpack the births of other nebulae, as well as the astrophysical forces at work in star interactions.

The images that unveiled this interstellar scene were released in June; only now have the researchers had time to sift through the data and present their interpretation.

So consider the images you’ve seen of Webb so far – they all have their own stories, which will (hopefully) be told in detail soon.

More: Are the colors in Webb Telescope images ‘wrong’?

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