List of Astronomy Acronyms - T

T

• TAC – (organization) Time Allocation Committee or Telescope Allocation Committee, a general name for a committee that awards telescope observing time
• TAC – (catalog) Twin Astrograph Catalog
• TAI – (astrophysics terminology) International Atomic Time
• TAMS – (astrophysics terminology) Terminal-Age Main Sequence, stars at the point in their lifetimes where they have finished burning hydrogen in their cores
• TAROT – (telescope) Télescope à Action Rapide pour les Objets Transitoires
• TASS – (observing program) The Amateur Sky Survey
• TAU – (spacecraft) Thousand Astronomical Unit, a spacecraft mission proposed in the 1980s that would reach 1000 AU in 50 years
• TCB – (astrophysics terminology) Barycentric Coordinate Time
• TCG – (astrophysics terminology) Geocentric Coordinate Time
• TDB – (astrophysics terminology) Barycentric Dynamical Time
• TDRSS – (communications network) Tracking and Data Relay Satellite System, an array of satellites used by NASA to communicate with many spacecraft in low Earth orbit
• TES – (instrumentation) Thermal Emission Spectrometer, a spectrometer on the Mars Observer
• TEP – (organization) Transits of Extrasolar Planets
• TGF – (celestial object) – Terrestrial gamma-ray flash, gamma rays emitted from Earth's lightning storms
• THEMIS – (instrumentation) Thermal Emission Imaging System, a camera on the Mars Odyssey spacecraft
• TIC – (catalog) Tycho Input Catalog, a predecessor of the Hipparcos Input Catalog
• TIMED – (spacecraft) Thermosphere Ionosphere Mesosphere Energetics and Dynamics
• TIE – (organization) Telescopes In Education
• TLP – (astrophysics terminology) Transient Lunar Phenomenon, an unexplained flash of light observed from the Moon
• TMC – (celestial object) Taurus Molecular Cloud
• TMT – (telescope) – Thirty Meter Telescope, formerly known as California Extremely Large Telescope
• TN – (person) Telescope Nut, nickname for an amateur telescope maker
• TNO – (celestial object) Trans-Neptunian Object, any object that orbits the Sun at a distance greater than that of Neptune
• TO – (person) Telescope Operator, the technician who assists in operating a telescope during astronomical observations
• TOPS – (meeting) Toward Other Planetary Systems, a series of educational astronomy workshops
• TPF – (telescope) Terrestrial Planet Finder, a planned space telescope that will be used to find extrasolar Earth-like planets
• TRACE – Transition Region and Coronal Explorer, a solar space telescope
• TrES – (telescope) Transatlantic Exoplanet Survey
• TT – (astrophysics terminology) Terrestrial Time
  • also TDT – Terrestrial Dynamical Time
• TTS – (celestial object) T-Tauri Star
• TWA – (celestial object) TW Hydrae Association
• TYC – (catalog) Tycho, a catalog that was the predecessor of the Hipparcos (HIP) Catalogue
• TZO – (celestial object) Thorne-Żytkow Object, the object that forms when a neutron star merges with a red giant