And because what is super old can sometimes be new, we take a look at the story of an aged star that is blowing off its outer atmosphere.

This is a completely expected phenomenon, and we see the results of this kind of behavior every time we look at a planetary nebula. This particular data set, however, is something totally new to researchers; we have never seen this in the process of happening.

And this is research that shows that context matters.

In the newly published image, we see a bright star in the center of a series of bright rings. Observed with the Atacama Large Millimeter Array (ALMA), it would be easy to misinterpret this image as being just another forming solar system with dust rings likely sheltering planets. But, it’s not. Any planetary rings this system had formed it used up billions of years ago. 

Today, there is a red variable star sitting in the center of the system, and for the past 800 years, it has been exhaling layers of its now expanded atmosphere. Each of these layers is now moving away from the star. Thanks to geometry and the ability to measure expansion rates, we know these rings were cast off 270, 485, and 780 years ago.

And unlike in planetary systems where the rings we see are actually rings in a disk, what we see here as a ring is a bit of an optical illusion. The star is expelling shells of material, but just like bubbles often appear as rings, we are only seeing the edges of these spheres.

This particular star, named V Hydrae, is located about 1300 light-years away and is just about double the size of our Sun. In the grand scheme of the universe, this makes them very similar stars, and we can anticipate our own Sun to someday exhale its atmosphere the same way. 

Through this mass shedding process, medium-sized stars reduce themselves to a naked core – a cooling-off white dwarf – while making their own unique planetary nebulae. Our systems planetary nebula will someday be shaped by both our Sun and how the material interacts with our planets and other minor bodies.

Hubble was actually justified, in part, as a mission to figure out the mysteries of planetary nebulae. It turns out that they are complicated, and it will take a few more generations of space telescopes to sort their details.

More Information

A new image captures enormous gas rings encircling an aging red star (Science News)

“The Rapidly Evolving AGB Star, V Hya: ALMA finds a Multi-Ring Circus with High-Velocity Outflows,” R. Sahai et al., to be published in The Astrophysical Journal (preprint on arxiv.org)