Abbreviation Definition
AAAAmateur Astronomers Association
AAAAAsociación Argentina Amigos de la Astronomía
AAADAmateur Astronomers Association of Delhi
AAADAmateur Astronomers Association Delhi
AAAMActive Amateur Astronomers of Maryland
AAGAmateur Astronomy Group
AALAstronomy Associates of Lawrence
AALAstronomy Associates of Lawrence Astronomy Associates of Lawrence
AASAmerican Astronautical Society
AASArchaeology, Astronautics, and Seti
AASCAstronomy and Astrophysics Survey Committee
AASIAstronomical Association of Southern Illinois
AATAnglo Australian Telescope
AAVAstronomical Analogue Video
AAVSOAmerican Association of Variable Star Observers
ABBAfter the Big Bang
ABBAADC Backend For Bolometer Array
ABFAstronomische Beeldverwerkings Faciliteiten
ACAscendant Cusp
ACActive Coronae