Subject
- open star clusters2
- photographic photometry2
- protostars2
- radio absorption2
- radio antennas2
- radio astrometry2
- radio interferometers2
- radio interferometry2
- radio observatories2
- radio spectra2
- radio spectrographs2
- radio spectrometers2
- radio telescopes2
- space astronomy2
- space telescopes2
- stellar associations2
- telescope arrays2
- trigonometric parallax2
- variable stars2
- very large array2
