Subject
- astronomical object identification5
- galaxy classification systems5
- millimeter astronomy5
- submillimeter astronomy5
- wide-band photometry5
- apparent magnitude4
- chemical abundances4
- diffuse molecular clouds4
- galaxies4
- line intensities4
- milky way galaxy4
- stellar distance4
- variable stars4
- astronomical models3
- co line emission3
- early-type stars3
- emission line stars3
- extinction3
- interstellar cloud3
- ob stars3
