Non-Detections—most recent: ethynylnaphthalene

Isotopologues—most recent: c-C2H3DO

Molecules can exist in a wide range of astrophysical environments, from the extremely cold regions between stars to the atmospheres of stars themselves. Molecules can be present in every stage of the life cycle of stars, from the diffuse and dense clouds that condense into protostellar and protoplanetary systems to mature systems like the Solar System.

Interstellar and Circumstellar Sources Intersystem Sources
Interstellar & Circumstellar Media
  NC4NH+,allylimine(tent)
Solar System Planets & Satellites
H2(Callisto), PH3(Venus,nd)
Protostars (IRAS 16293-2422)
CHD2OH 
Planetoids
  HNC (Pluto) 
Protoplanetary Disks
CH3OCH3 (Oph IRS 48)
Comets
  NH4SH,NH4F (comet 67P) 
Brown Dwarfs and Stellar Atmospheres
AlH (Proxima Centauri) 
Exoplanets
H2O(WASP-20b,HAT-P-18b) 

Some detections reported on these pages may be controversial, but all are taken from the peer-reviewed astronomical literature. A questionable identification may be removed at a later date if circumstances warrant.

Jacque Crovisier has amassed a comprehensive compilation of species observed to date in the interstellar medium, in comets, or in non-terrestrial planetary atmospheres, plus additional ones which may prove to be found.

See the ApJS article by Brett McGuire, 2021 Census of Interstellar, Circumstellar, Extragalactic, Protoplanetary Disk, and Exoplanetary Molecules. In addition to lists of observed molecules, the article provides a good overview about astronomical observation and the spectroscopy associated with detecting molecules.

CREDIT: Image modified from imagine.gsfc.nasa.gov/Images/objects/stars_lifecycle.jpg (NASA & Night Sky Network).

Maintained by DE Woon
Updated 5 February 2023