Subject
- cosmology9
- h-alpha-photometry9
- h-beta-photometry9
- interstellar reddening9
- interstellar-line-emission9
- galactic and extragalactic astronomy8
- galaxy-ages8
- astronomical reference materials7
- exoplanet astronomy7
- exoplanets7
- kron-cousins photometry7
- solar system astronomy7
- stellar astronomy7
- young stellar objects7
- novae6
- horizontal branch stars5
- magellanic clouds5
- north galactic pole5
- optical observation5
- photographic magnitude5