Encyclopedia of Astrobiology

Living Edition
| Editors: Muriel Gargaud, William M. Irvine, Ricardo Amils, Henderson James Cleaves, Daniele Pinti, José Cernicharo Quintanilla, Michel Viso


  • William M. Irvine
Living reference work entry
DOI: https://doi.org/10.1007/978-3-642-27833-4_1831-4



The 3-carbon ring molecule C3H2 is classified chemically as a carbene and is highly reactive in the laboratory. It was the first cyclic molecular species detected in interstellar molecular clouds. Immediately following its identification at short radio wavelengths, it was discovered to be nearly ubiquitous in the interstellar medium (Matthews and Irvine 1985), and it has subsequently also been found in the envelope of evolved carbon-rich stars (evolved stars are those which have completed their main hydrogen fusion stage and are thus nearing the end of their energy-producing lifetimes). The linear isomer of C3H2 is also detected in molecular clouds, but its abundance is typically an order of magnitude lower than that of the cyclic isomer (Cernicharo et al. 1991). In diffuse clouds, the abundance ratio between the linear and the cyclic isomers increases by a factor 10 with respect to that observed in dense molecular clouds (Cernicharo et al. 1999). Both...


Emission Line Interstellar Medium Molecular Cloud Rotational Transition Abundance Ratio 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.
This is a preview of subscription content, log in to check access.

References and Further Reading

  1. Cernicharo J, Gottlieb CA, Guelin M, Killian TC, Paubert G, Thaddeus P, Vrtilek JM (1991) Astronomical detection of linear H2CCC. Astrophys J 368:L39–L42CrossRefADSGoogle Scholar
  2. Cernicharo J, Cox P, Fosse’ D, Gusten R (1999) Detection of linear C3H2 in absorption toward continuum sources. Astron Astrophys 351:341–346ADSGoogle Scholar
  3. Matthews HE, Irvine WM (1985) The hydrocarbon ring C3H2 is ubiquitous in the galaxy. Astrophys J 298:L61–L64CrossRefADSGoogle Scholar
  4. Thaddeus P, Vrtilek JM, Gottlieb CA (1985) Laboratory and astronomical identification of cyclopropenylidene, C3H2. Astrophys J 299:L63–L66CrossRefADSGoogle Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  1. 1.Department of AstronomyUniversity of Massachusetts, Lederle Graduate Research Tower B 619EAmherstUSA