Using Spitzer Space Telescope data, astronomers have made the first detection of the C₆₀ fullerene molecule in young stellar objects, and found a further example alongside nano-diamonds in a more evolved star.

Fullerenes, known informally as buckyballs, are comprised of 60 carbon atoms arranged into a hollow sphere. The similarity of the shape to the architect Buckminster Fuller's geodesic domes earned the molecule the name buckminsterfullerene, or buckyball for short. The first definite discovery of C₆₀ outside the Earth was made in 2010 by the Spitzer Space Telescope, and until now had only been detected in the interstellar medium and in the later stages of stellar evolution.

Two new examples reported by Peter Sarre of the University of Nottingham and colleagues this week at the National Astronomy Meeting are located around young stellar objects in the galactic centre.

“They’re found in the central molecular zone towards the galactic centre, around stars where planets could be born,” Sarre tells Astronomy Now, who also reports detection in a further candidate in the Rosette nebula and in a more evolved Herbig Ae/Be star that is approaching the main sequence of stellar evolution. “Right from the deaths of stars and associated carbon materials being pushed out through the interstellar medium (ISM) through planetary nebulae, and then being found in the ISM itself, this is like completing the story finding C₆₀ right where new stars are forming in collapsing gas clouds.”

In addition, the scientists report the presence of C₆₀ in an unusual post-asymptotic giant branch star, a late period of evolution undertaken by stars of less than ten solar masses. “Along with one other example they’re the only cases where nano-diamonds are being observed with C₆₀,” says Sarre. “Infrared emission tells us that they are diamonds, so it suggests some link exists between the presence of fullerenes and nano-diamonds.”

The findings extend the range of astrophysical environments in which C₆₀ has been reported and raises questions about the mechanisms for its formation. “One possibility is that flat graphene-like carbon, also seen in the young stellar objects, is damaged by shocks or ultraviolet radiation and then curls into the spherical shape of C₆₀,” adds Sarre.

The results are reported in a paper scheduled to appear in the Monthly Notices of the Royal Astronomical Society led by PhD student Kyle Roberts.