The mystery of the fullerenes in space explained

Centre of the planetary nebula M57, taken by the astrophotographer Dr. Robert Gendler, and John Bozeman. Credits: NASA/ESA
Advertised on

A pioneering study from the Instituto de Astrofísica de Canarias (IAC) which combines laboratory chemistry with astrophysics, has shown for the first time that grains of dust formed by carbon and hydrogen in a highly disordered state, known as HAC, can take part in the formation of fullerenes, carbon molecules which are of key importance for the development of life in the universe, and with potential applications in nanotechnology. The results are published as a Letter to the Editor in the prestigious journal Astronomy & Astrophysics.

Fullerenes are carbon molecules which are very big, complex, and highly resistant, Their atoms are organized in three dimensional spherical structures, with a pattern of alternating hexagons and pentagons, shaped like a football (C60 fullerenes) or a rugby ball (C70 fullerenes).

These molecules were discovered in the laboratory in 1985, which procured the Nobel Prize for Chemistry for their three discoverers 11 years later. Since then there have been many instances of observational proof of their existence in space, especially within the gas clouds around old, dying stars the size of the Sun, called planetary nebulae, which have been expelled from the outer layers of the stars towards the end of their lives. 

As these molecules are highly stable and difficult to destroy, it is thought that the fullerenes can act as cages for other molecules and atoms, so that they could have brought complex molecules to Earth, which gave an impulse to start life. So their study is important for the understanding of the basic physical processes which take part in the organization of organic material in the universe.

An unknown chemical footprint

Spectroscopy is essential for the search and identification of fullerenes in space. Spectroscopy allows us to study the material composing the universe by analyzing the chemical footprints made by atoms and molecules on the light which reaches us from them.

A recent study, led entirely from the IAC, has analyzed infrared spectroscopic data obtained previously from telescopes in space, from the planetary nebula Tc1.  These spectra show spectral lines indicating the presence of fullerenes, but also show broader infrared bands, (UIR for their initials in English) which are detected widely in the universe, from the small bodies in the Solar System to distant galaxies.

“The identification of the chemical species which causes this infrared emission, widely present in the universe, was an astrochemical mystery, although it was always thought probable that it is rich in carbon, one of the basic elements of life” explains Marco A. Gómez Muñoz, an IAC researcher, who led this study.

A new origin for the fullerenes

In order to identify these mysterious bands, the research team reproduced the infrared emission of the planetary nebula Tc 1. Analysis of the emission bands showed the presence of grains of amorphous hydrogenated carbon (HAC). These compounds of carbon and hydrogen in a highly disordered state, very abundant in the envelopes of dying stars, can account for the infrared emission of this nebula.

“We have combined for the first time, the optical constants of HAC, obtained from laboratory experiments, with models of photoionization, and doing this we have reproduced the infrared emission of the planetary nebula Tc 1, which is very rich in fullerenes", explains Domingo Anibal García Hernández, an IAC researcher who is a coauthor of the paper.

For the research team the presence in the same object of HAC and fullerenes supports the theory that the fullerenes could have formed during the process of destruction of the dust grains, for example by interaction with ultraviolet radiation, which is much more energetic than visible light.

With this result the scientists have opened the way for furture research based on collaboration between laboratory chemistry and astrophysics. “Our work shows clearly the great potential of interdisciplinary science, and technology to make basic advances in astrophysics and astrochemistry” concludes Gómez Muñoz.

Article: M. A. Gómez-Muñoz et al. “Hydrogenated amorphous carbon grains as an alternative carrier of the 9–13 μm plateau feature in the fullerene planetary nebula Tc 1”. A&A, Volume 682, L18, February 2024. DOI:

Contacts at the IAC:
Marco A. Gómez Muñoz, marco.gomez-ext [at] (marco[dot]gomez-ext[at]iac[dot]es)
Domingo Aníbal García Hernández, anibal.garcia.hernandez [at] (anibal[dot]garcia[dot]hernandez[at]iac[dot]es)

Related projects
Project Image
Nucleosynthesis and molecular processes in the late stages of Stellar Evolution
Low- to intermediate-mass (M < 8 solar masses, Ms) stars represent the majority of stars in the Cosmos. They finish their lives on the Asymptotic Giant Branch (AGB) - just before they form planetary nebulae (PNe) - where they experience complex nucleosynthetic and molecular processes. AGB stars are important contributors to the enrichment of the
Domingo Aníbal
García Hernández
Related news
Fullerenes discovered in a star formation region in Perseus
A study carried out by IAC researcher Susana Iglesias-Groth has detected molecules of pure carbon in one of the nearest star formation regions to the Solar System. The results of this work have recently been published in the journal Monthly Notices of the Royal Astronomical Society. Fullerenes are carbon molecules , whose structure contains pentagons and hexagons, which often appear in key molecules for life . They are also the third most stable form of carbon, together diamond and graphite. A study performed by the researcher at the Instituto de Astrofísica de Canarias (IAC) Susana Iglesias
Advertised on
Aníbal García-Hernández y Arturo Manchado han liderado el descubrimiento de enormes cantidades de buckyesferas o fulerenos, moléculas de carbono con forma de balón de fútbol, en la Vía Láctea y otra galaxia cercana.Los fulerenos han sido detectados, gracias al telescopio Spitzer de la NASA, acompañados de grandes cantidades de hidrógeno, lo que contradice las teorías actuales.Estas moléculas, las más grandes conocidas en el espacio, pudieron transportar las semillas para que comenzara la vida en la Tierra.
Advertised on
Fullerenes and graphenes
On November 1st the COST ( European Cooperation in Science and Technology) action called “NanoSpace: Molecular carbon nanostructures in space” coordinated by the Instituto de Astrofísica de Canarias (IAC) was initiated. This is an internatonal research network, led by Anibal García Hernández, in which groups from 43 countries are participating. This is the first time that an IAC researcher has led one of these prestigous COST actions. The main objective of NanoSpace is to determine the abundance, the formation mechanisms, and the astrochemical and astrobiológical roles of carbon
Advertised on