List of Astronomy Acronyms - O

O

• OAO – (observatory) Okayama Astrophysical Observatory, in Japan
• OAO – (telescope) Orbiting Astronomical Observatory, a series of satellites with astronomical instruments that operated in the 1970s
• OC – (celestial object) Open Cluster, a cluster of stars
• OCA – (organization) Observatoire de la Côte d'Azur
• OCO – (celestial object) Oort Cloud Object, an object (usually a comet) in the Oort cloud
• OGLE – (observing program/catalog) Optical Gravitational Lensing Experiment, an observing program to survey the sky for microlensing events; also the catalog of sources produced by the project
  • BLG – (catalog) BuLGe, used to designate a source detected in the direction of the bulge of the Milky Way
  • TR – (catalog) TRansit, used to designate a potential observation of a microlensing event caused by a transiting star
• OPAG – (organization) Outer Planets Assessment Group, a group established by NASA that provides advice on solar system exploration
• ORFEUS – (telescope) Orbiting and Retrievable Far and Extreme Ultraviolet Spectrometer, an ultraviolet space telescope that could be released and later retrieved by the Space Shuttle
• OSSE – (instrumentation) Oriented Scintillation Spectrometer Experiment, an instrument on the Compton Gamma Ray Observatory
• OTA – (instrumentation) Optical Telescope Assembly, the optics of the Hubble Space Telescope
• OVV – (celestial object) An Optically Violent Variable quasar.
• OWL – (telescope) Orbiting Wide-angle Light-collectors, two satellites that will work together to observe cosmic rays hitting the Earth's atmosphere
• OSS Ohio Sky Survey
• OWL – (telescope) OverWhelmingly Large Telescope, a proposed telescope with a primary mirror with a width of 100 m