Subject
- f stars5
- h ii regions5
- peculiar variable stars5
- planetary nebulae5
- star forming regions5
- stellar associations5
- galaxy rotation4
- proper motions4
- stellar spectral types4
- absolute magnitude3
- accretion3
- be stars3
- bl lacertae objects3
- ccd photometry3
- co line emission3
- galaxy planes3
- horizontal branch stars3
- millimeter astronomy3
- nebulae3
- optical observation3
