NASA/JPL-Caltech/Center for Astrophysics | Harvard & Smithsonian
Crop from a large mosaic obtained by the Spitzer Space Telescope and showing the “Diamond Ring” structure in the center, a structure that is located in the wider Cygnus X star formation region. Click on the image to see its entirety
The enormous structure does not have a rapidly expanding spherical shell, as is usual, but only a slowly expanding ring — which ‘burst’ because gases managed to escape into the thinner areas around it.
An international team led by researchers from the University of Cologne, Germany, has solved the mystery of an extraordinary phenomenon known as the “Diamond ring” in the star forming region Cygnus X.
The enormous ring-shaped structure, made of gas and dust, resembles a glittering diamond ring; in similar structures, the formations are not flat, but spherical.
How this special form arose, until now unknown, was explained in a publication in the magazine Astronomy & Astrophysics.
The ring has a diameter of about 20 light years and shines brightly in the infrared. It’s the relic of an ancient cosmic bubble which was formed by the radiation and winds of a massive star.
In contrast to other similar objects, the “Diamond Ring” does not have a rapidly expanding spherical shell, but only a slowly expanding ring.
“For the first time, we observed the final phase of a gas bubble in a clearly flat cloud structure,” he explains. Simon Dannhauerfrom the Institute of Astrophysics at the University of Cologne, who led the study.
“The bubble ‘burst’, because the gases managed to escape for the thinner areas around you. All that remained was its particular flat shape.”
Computer simulations, carried out by Sebastian Widerfrom the University of Cologne, on the new supercomputer “RAMSES”, show that the bubble initially expanded in all directions and later escaped perpendicularly to the cloud.
What remained was the “Diamond Ring” structure that is visible today. It is estimated that this cosmic formation has about 400,000 yearsvery young when compared to the lifetime of massive stars.
The bubble, made up of ionized carbon, was once inflated by a hot star with a mass about 16 times that of our Sun. This star heats the gas and dust until they glow.
Observations like this are technically very demanding and were only possible with the help of the retired aerial observatory SOFIA (Stratospheric Observatory for Infrared Astronomy).
With the SOFIA, a modified Boeing plane which flew at an altitude of 13 kilometers or more, researchers were able to observe a range of wavelengths of light that is not accessible from Earth.
Thus, the researchers precisely measured the movement of the gas: the ring expands at around 1.3 kilometers per second – which corresponds to around 4700 km/h It’s actually quite slow compared to similar bubbles.
The discovery provides valuable insights into how radiation and winds from young stars shape their environment and therefore also influence the formation of new stars.
“The ‘Diamond Ring’ is an excellent example of how enormous the influence of individual stars can be on cloud complexes,” says Nicola Schneiderco-author of the study. “These processes are crucial to understanding the formation of stars in our Milky Way”, adds the co-author Robert Simon.
However, there is still a little disappointment for romantics. The study also shows that what appears to be a “Diamond Ring” seen from Earth is, in reality, consisting of two individual objects.
The “Diamond,” a cluster of young stars, just appears to be part of the ring. In fact, it is located a few hundred light years in front of the ring.
