New Delhi: An international team of researchers have investigated a mysterious feature in a nearby stellar nursery, Cygnus X. The ring0shaped structure is made up of gas and dust, and is about 20 lightyears across, shining brightly in infrared frequencies. Similar structures have been discovered in star forming regions before, but these are spherical in shape. Such bubbles are blown by the radiation and winds from massive stars, that live fast and die young. The research reveals that the bubble has burst, with the gases escaping to low-density regions in the surroundings, leaving behind the peculiar flat ring.
Sophisticated computer simulations indicated that the bubble would have expanded in all directions, with material perpendicular to the cloud escaping, leaving behind the ‘Diamond Ring’ visible today. The formation is estimated to be around 400,000 years old, which is a very short period in the lives of massive stars. The star that blew the bubble of ionized carbon contained about 16 times the mass of the Sun. The technically demanding observations were conducted by the SOFIA (Stratospheric Observatory for Infrared Astronomy) airborne observatory, that was essentially a telescope mounted on a modified Boeing aircraft. The ring is expanding at around 1.3 km per second, or 4,700 kmph, which is slow compared to similar bubbles.
The features carved by young stars
The discovery sheds light on how the energetic radiation and winds from newborn stars can shape their environments and influence the formation of new stars. The intense stellar winds can blow away gas and dust in some regions, while causing the star forming material to concentrate and clump up in others, resulting in the formation of more stars. The diamond in the ring is not a cluster of young stars, but a part of the ring, located a few hundred lightyears in front of it. A paper describing the research has been published in Astronomy and Astrophysics.