| Empirical Formula |
Name | Isotopic Species |
Spectral Region |
CA Number |
Reference |
|---|---|---|---|---|---|
| Interstellar and Circumstellar Species | |||||
| CH+ | Methyliumylidene | CH+ | IR | [24361-82-8] | Cer97, Dou41 |
| CH3 | Methyl | CH3 | IR | [2229-07-7] | Feu00 |
| CH4 | Methane | CH4 | IR | [74-82-8] | Lac91 |
| CO2 | Carbon dioxide | CO2 | IR | [124-38-9] | Jus96 |
| C2 | Carbon molecule | C2 | UV | [12070-15-4] | Cha80 |
| C2H2 | Ethyne (acetylene) | HCCH | IR | [74-86-2] | Lac89 |
| C2H4 | Ethylene | H2CCH2 | IR | [74-85-11] | Cer01a |
| C4H2 | 1,3-Butadiyne | HCCCCH | IR | [460-12-8] | Cer01a |
| C5 | Pentacarbon molecule | C5 | IR | [12595-82-3] | Ber89 |
| C6H2 | 1,3,5-Hexatriyne | HCCCCCCH | IR | [3161-99-7] | Cer01a |
| C6H6 | Benzene | C6H6 | IR | [71-43-2] | Cer01 |
| HN | Imidogen | HN | UV | [13774-92-0] | Mey91, Swi41 |
| HS | Mercapto (thiohydroxyl) | SH | IR | [13940-21-1] | Yam00 |
| H2 | Hydrogen | H2 | UV | [1333-74-0] | Car70 |
| H3+ | Hydrogen ion | H3+ | IR | [28132-48-1] | Geb96 |
| H4Si | Silane | SiH4 | IR | [7803-62-5] | Kea93 |
| N2 | Nitrogen | N2 | UV | [7727-37-9] | Kna04 |
| Species Observed Only in Comets. | |||||
| CN+ | Cyanogen ion | CN+ | UV | [12539-57-0] | Val92 |
| CN2 | Cyano imidogen | NCN | UV | [1884-64-6] | Val92 |
| CO2+ | Carbon dioxide ion | CO2+ | UV | [12181-61-2] | Swi50 |
| C2H6 | Ethane | CH3CH3 | IR | [74-84-0] | Wea99 |
| HO+ | Oxoniumylidene | OH+ | UV | [12259-29-9] | Val92 |
| H2O+ | Oxoniumyl | H2O+ | UV | [56583-62-1] | Weh74 |
| N2+ | Nitrogen ion | N2+ | UV | [13966-04-6] | Lut93 |
| S2 | Sulfur | S2 | UV | [23550-45-0] | A'H83 |