Fullerenes and fullerene-related molecules in the circumstellar environment of evolved stars

Díaz-Luis, J. J.; García-Hernández, D. A.; Kameswara Rao, N.; Manchado, A.; Cataldo, F.
Bibliographical reference

Highlights on Spanish Astrophysics IX, Proceedings of the XII Scientific Meeting of the Spanish Astronomical Society held on July 18-22, 2016, in Bilbao, Spain, ISBN 978-84-606-8760-3. S. Arribas, A. Alonso-Herrero, F. Figueras, C. Hernández-Monteagudo, A. Sánchez-Lavega, S. Pérez-Hoyos (eds.), 2017 , p. 501-501

Advertised on:
3
2017
Number of authors
5
IAC number of authors
4
Citations
0
Refereed citations
0
Description
Fullerenes, highly resistant and stable tridimensional carbon molecules, have attracted much attention since their discovery at laboratory by Kroto and collaborators; e.g., fullerenes and fullerene-related molecules may explain several phenomena in Astrophysics such as the diffuse interstellar bands (DIBs) and the UV bump. The recent detection of the most common fullerenes (C_{60} and C_{70}) in the circumstellar environment of evolved stars like planetary nebulae (PNe) has raised the idea that other forms of carbon such as hydrogenated fullerenes, buckyonions, and carbon nanotubes may be widespread in the Universe and it has permitted to study the DIBs towards fullerene-rich space environments for the first time. In particular, here we present: i) the first possible detection of two diffuse bands of circumstellar origin (diffuse circumstellar bands, DCBs) at 4428 and 5780 Å around PN Tc1; and ii) the non-detection of fullerene-related molecules such as hydrogenated fullerenes(fulleranes like C_{60}H_{36} and C_{60}H_{18}) in the 3-5 μm spectral range in C_{60}-rich PNe. Our non-detections together with the (tentative) fulleranes detection in a proto-PN suggests that fulleranes may be formed in the short transition phase between asymptotic giant branch (AGB) stars and PNe but they are quickly destroyed by the UV radiation field from the central star.