The methanol–methyl cyanide correlation: A chemical path from protostars to comets
Year: 2026
Type: article
Abstract: Context. Comets are the frozen remnants of the early Solar System. By investigating their chemical composition, we can unveil the physical processes that shaped our planetary system and the evolution of interstellar material into planetary building blocks. Aims. Systematic comparisons of the chemical composition of protostellar environments, disks, and comets remain rare and are often restricted to a narrow selection of targets. This study overcomes these limitations by employing a broader statistical approach that allowed us to identify inconsistencies in existing datasets. It thus provides a more comprehensive overview. Methods. We present the first statistical analysis of methyl cyanide (CH 3 CN) and methanol (CH 3 OH) across a diverse and consistent sample, including 13 comets, 24 low-mass hot corinos, and seven planet-forming disks. We focused on the [CH 3 CN]/[CH 3 OH] abundance ratio, which is strongly correlated in hot corinos and might provide a sensitive diagnostic of the thermal and chemical evolution from interstellar clouds to planetary building blocks. Results. While the [CH 3 CN]/[CH 3 OH] abundance ratios vary significantly within the planet-forming disk sample, this ratio is remarkably similar in comets and hot corinos. This indicates that despite material reprocessing, a consistent chemistry regulates the transition from protostellar envelopes to comets over time. Additionally, the correlation between CH 3 CN and CH 3 OH in comets appears to be weaker than in hot corinos, and it shows a potential dichotomy that might be related to different formation epochs, different formation regions in the disk, or post-formation thermal processing. Conclusions. A statistical and multidisciplinary approach is essential to establish a robust baseline for characterizing the heterogeneity of planet-forming regions and comets. This helps us to identify differences and caveats that would remain hidden in single-source studies, with the risk of biasing the resulting conclusions. The expansion of these sample sizes will provide the statistical power needed to investigate the origins of our planetary system and other planetary systems.
Source: Astronomy and Astrophysics
Institutions: Arcetri Astrophysical Observatory, National Institute for Astrophysics, Goddard Space Flight Center, Catholic University of America, University of Leeds, Center for Astrophysics Harvard & Smithsonian, Observatoire de Paris, Laboratoire d’études spatiales et d’instrumentation en astrophysique, Université Grenoble Alpes, American University
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,865
OpenAlex ID: W7223844441