2 Stellar; Stellar photospheric spectra; B-type to early M-type.
 3 Stellar; Lower temperature stellar continuum spectra with no features: mid to
 3  late M-type, little circumstellar dust.
 1 Carbon star; Strong 11.3{mu}m emission.
10 Carbon star; Lower temperature continuum (~250K), e.g., AFGL 3068 and no 
10  strong features
15 Carbon star; Weaker 11.3{mu}m emission.
 5 Oxygen-rich AGB star; Silicate absorption on an intermediate temperature 
 5  continuum (400-200K) 
 6 Oxygen-rich AGB star; Stronger 10{mu}m emission on a higher temperature 
 6  continuum (>=600K)
12 Oxygen-rich AGB star; Weaker 10{mu}m emission on a higher temperature 
12  continuum ({=600K).
13 Oxygen-rich AGB star; 10{mu}m features in transition from emission to 
13  absorption.
 0 Planetary nebulae and post-AGB sources; Emission lines.
 8 Planetary nebulae and post-AGB sources; Silicate emission on a low 
 8  temperature continuum (oxygen-rich PN and PPN).
11 Planetary nebulae and post-AGB sources; Lower temperature (~150K) featureless
11  (carbon-rich PN and PPN).
14 Planetary nebulae and post-AGB sources; 21{mu}m emission feature 
14  (carbon-rich PPN).
 4 ISM spectra: mostly HII regions includes a few PN PPN, and galaxies; UIR or 
 4  PAH features on a flat continuum (HII regions, galaxies, a few PN & PPN).
 7 ISM spectra: mostly HII regions includes a few PN PPN, and galaxies; 
 7  Low temperature continuum (<=100K).
 9 ISM spectra: mostly HII regions includes a few PN PPN, and galaxies; 10{mu}m 
 9  absorption on a low temperature continuum (<=100K), includes a few PPN.
16 ISM spectra: mostly HII regions includes a few PN PPN, and galaxies; UIR or 
16  PAH features on a low temperature continuum (<=100K), includes a few PN.