Subject
- spectroscopy30
- stellar spectral types26
- radial velocity24
- radio continuum emission24
- gamma-ray astronomy22
- galaxy clusters19
- magellanic clouds19
- quasars17
- apparent magnitude14
- molecular clouds14
- stellar masses14
- stellar associations13
- astrographic catalogs12
- h ii regions12
- radio galaxies12
- trigonometric parallax12
- ultraviolet photometry12
- bl lacertae objects11
- chemical abundances11
- milky way galaxy11
