'Diamond Ring' in Cygnus X may be remnants of burst bubble: Study
A study led by University of Cologne have uncovered the mystery in "Diamond Ring" in the Cygnus X star-forming region, a glowing, flat cosmic ring of gas and dust spanning 20 light years. Using SOFIA observations and computer simulations, they found that it's remnant of an expanding bubble created by a massive star. "Diamond Ring" is around 4,00,000 years old.