Astronomers have solved the mystery behind the unusual ‘Diamond Ring’ nebula in the Cygnus X star-forming region: it’s the remnant of a burst gas bubble, flattened by escaping gases. Unlike most similar structures, which are spherical, this nebula appears as a distinct, ring-shaped formation. The discovery, published in Astronomy & Astrophysics, provides key insights into how massive stars shape their surroundings and influence future star birth.
The Anatomy of a Burst Bubble
The ‘Diamond Ring’ spans roughly 20 light-years and shines brightly in infrared light. It originated from a massive star—approximately 16 times the mass of our Sun—that emitted intense radiation and stellar winds. This energy inflated a bubble of ionized carbon gas, which initially expanded in all directions.
However, instead of maintaining a spherical shape, the bubble ‘burst’ as gases escaped through weaker areas. This resulted in the unique, flattened structure we observe today. Computer simulations confirm this process, showing how the initial expansion gave way to a slow, ring-like expansion. The entire formation is relatively young, estimated to be around 400,000 years old.
The Role of SOFIA and Infrared Astronomy
Observing this phenomenon required specialized equipment. The research team relied on SOFIA (Stratospheric Observatory for Infrared Astronomy), a modified Boeing aircraft equipped with an infrared telescope. Flying at high altitudes, SOFIA can access wavelengths of light blocked by Earth’s atmosphere.
Precise measurements from SOFIA revealed that the ring expands at approximately 1.3 kilometers per second (4,700 km/h), which is slower than comparable bubbles. This slow expansion is consistent with the escaping gas model.
Implications for Star Formation
The ‘Diamond Ring’ serves as a prime example of how individual stars can dramatically shape their surrounding environment. The energy released by massive stars influences the density and distribution of gas and dust, which in turn affects the formation of new stars.
“Such processes are crucial for understanding how stars are born in our Milky Way,” explains co-author Dr. Nicola Schneider. The discovery highlights the dynamic interplay between massive stars and their surroundings, offering new insights into the cycle of star birth and evolution
