Molecular seeds of dust grains

Identify which molecules act as seeds for dust grains in the dust-formation zones of evolved stars, particularly through sensitive, wide-band spectral observations of unassigned molecular features.

Background

The paper emphasizes that the molecular inventory of dust-formation zones is incomplete and that many detected spectral features remain unassigned. Identifying the molecules that initiate grain formation is presented as necessary for understanding the transition from molecular precursors to macroscopic dust grains. The proposed ALMA2040 capabilities—greater sensitivity and wider instantaneous bandwidth—would enable searches for spectral patterns and systematic characterization of these candidate species.

References

In fact, we do not know which molecules act as seeds of the dust grains and more sensitive observations with larger bandwidth would be critical to e.g. search for spectral patterns for the characterization of all the unassigned detected features, which are probably important for the dust formation processes, that we currently have in the few but best studied objects, such as IRC+10216 \citep{2013ApJ...778L..25C}.

— Evolved stars: dust formation and mass loss  (2610.21851 - Velilla-Prieto et al., 15 Oct 2026) in Section 3, subsection “Expected impact”