March 5, 2013
C60 Fluorine Creates ‘Soccer Balls’ In Space
Lee Rannals for redOrbit.com - Your Universe Online
An international team of astronomers are reporting in The Astrophysical Journal they have spotted what resembles a soccer ball sitting in the dying star M1-11.
Five instruments helped astronomers detect C60 fluorine in the dying star, which are molecules of carbon with 60 atoms arranged in patterns that resemble a soccer ball.
Astronomers used the Subaru Telescope, the Spitzer Space Telescope (SST), ESO's Very Large Telescope, the 1.88-meter telescope at the Okayama Astrophysical Observatory, and the Japanese infrared astronomy satellite AKARI for the study. Their research is helping to get a better grasp of the prevalence and formation of C60 in space.
Interstellar space is filled with minute particles called "dust," which are grains ejected into interstellar space from dying stars. Looking into the amount and composition of the dust produced by dying stars as well as its subsequent return to interstellar space is a big step in helping astronomers understand stellar evolution and the chemical evolution of galaxies.
C60 is an extremely stable molecule, so it can easily form in laboratories on Earth, and scientists believe it is very abundant in interstellar space. Scientist do not know how prevalent it is or what sort of environment is necessary to produce it, but they started detecting the molecule in 2010 and have found it in 20 objects so far.
The team looked at a class of dying stars known as "planetary nebulae," because cosmic C60 has been detected before in these objects.
Masaaki Otsuka from Academia Sinica Institute of Astronomy and Astrophysics, who led the research, analyzed all of the relevant spectroscopic data taken by the SST and analyzed spectral data from over 300 planetary nebulae. The astronomers identified C60 in several planetary nebulae, including M1-11.
According to the findings, C60 only makes up about 0.01 percent of the total dust mass in M1-11. Based on these findings, Otsuka concluded C60 is very rare in the interstellar medium, which is the matter that exists in the space between the star system in a galaxy.
In order to find how C60 forms in space, the team had to characterize the physical conditions in the environments that contain the molecule. Otsuka applied the method of elemental abundance analysis to reveal the evolutionary status of M1-11's nebula and its progenitor star. They found M1-11 is a young planetary nebula that formed from material ejected by the star 1,000 years ago.
The researchers say the C60 mass and temperature, the elemental composition of the gas in the nebula, the mass of the progenitor star, and the evolutionary status are similar to those seen in other planetary nebula that continua the molecule.
Scientists have also recently discovered prebiotic molecules in interstellar space, indicating some basic chemicals considered to be key steps in building life may have formed on dusty ice grains floating between stars. Scientists studied a giant cloud of gas about 25,000 light-years from Earth, finding the cloud contains a molecule thought to be a precursor to a key component of DNA.
“Finding these molecules in an interstellar gas cloud means that important building blocks for DNA and amino acids can ℠seed´ newly-formed planets with the chemical precursors for life,” said Anthony Remijan, of the National Radio Astronomy Observatory (NRAO).
They wrote in the Astrophysical Journal this discovery suggests the chemical formation sequence for these molecules occurred on the surface of ice grains in interstellar space, instead of in gas.
Image 2 (below): The structure of fullerene C60. Credit: NAOJ