ABBR,MEANING 21CSLC,21st Century Space Launch Complex 4LGSF,Four-Laser Guide Star Facility 4MOST,4-metre Multi-Object Spectroscopic Telescope (Proposed new spectroscopic instrument for VISTA) 4T,Four Telescope (VLTI mode) A&A,"Journal, Astronomy & Astrophysics" A&ARv,"Journal, Annual Review of Astronomy and Astrophysics" AAA,Amateur Astronomers Association of New York ACD,Amplitude Calibration Device (ALMA) ACM,"Asteroids, Comets, and Meteors" ACe,Astaldi Cimolai EIE (Consortium) ADA,ALMA Department of Administration ADO,ALMA Director’s Office ADS,International Italian optics company working on the DSM for the VLT AEM,ALMA construction consortium AFNOR,"Association Française de Normalisation" AFTA,Astrophysics Focused Telescope Assets AGN,Active Galactic Nucleus AIDA,Astronomical Infrastructure for Data Access AIP,Leibniz Institute for Astrophysics Potsdam AIT,"Assembly, Integration and Test" AIV,"Assembly, Integration and Verification" AJ,The Astronomical Journal ALMA,Atacama Large Millimeter/submillimeter Array AMBER,"Astronomical Multi-BEam combineR (VLTI Instrument)" AN,"Journal, Astronomische Nachrichten" Antu,VLT Unit Telescope 1 AO,Adaptive Optics AOF,Adaptive Optics Facility AOS,"Array Operations Site (ALMA)" APE,Active Phasing Experiment APEX,Atacama Pathfinder Experiment ApJ,Astrophysical Journal ApJS,"Journal, Astrophysical Journal Supplement Series" AQUARIUS,"Mid-infrared detector array (VISIR)" ARAL,Alignment facility for the VLTI ARC,"ALMA Regional Centre, or Ames Research Center" ArTeMiS,Bolometric camera for APEX ASAC,ALMA Science Advisory Committee ASIAA,"East Asia FEIC (ALMA)" ASIC,Application Specific Integrated Circuit ASSIST,Adaptive Secondary Setup and Instrument Simulator (AOF test bench) AstraLux,"Lucky Imaging camera for the Calar Alto 2.2-metre telescope" AT,Auxiliary Telescope for the VLTI ATC,"Astronomy Technology Centre (United Kingdom)" ATILO,Administrative Tribunal of the International Labour Organisation AU,"Astronomical Unit, the distance between the Earth and the Sun" AUI,Associated Universities Inc. AVM,Astronomical Visualisation Metadata AXP,"Anomalous X-Ray Pulsar" BAM,Construction company for the Headquarters extension BE,Back-End (ALMA) BELLA,Building Europe Link to Latin America BFL,Budget and Forward Look BH,Black hole BLAST,Balloon-borne Large Aperture Submillimeter Telescope BlackGEM,(La Silla) Telescope array searching for optical counterparts of gravitational wave sources BLIP,Background photon noise limited C2PAP,"Computational Center for Particle and Astrophysics, Universe Cluster, Garching" CADC,Canadian Astronomy Data Centre CAPj,Communicating Astronomy with the Public Journal CARLA,Clusters Around Radio-Loud AGN (Spitzer) CASA,Common Astronomy Software Applications (ALMA) CBR,cosmic background radiation CDR,Critical Design Review CDS,"Centre de Données astronomiques de Strasbourg (Strasbourg astronomical Data Center)" CEA,"Commissariat à L’Energie Atomique, France" CELAC_EU,"Summit of the Community of Latin American and Caribbean States–European Union" CES,Coude Echelle Spectrometer CGM,Circumgalactic medium CHAMP+,Dual channel heterodyne receiver array (APEX) CLIF,Convolution with Linearized Inverse Filter algorithm for wavefront sensing CM,center of mass CMB,Cosmic Microwave Background CMBR,Cosmic Microwave Background Radiation CME,Coronal Mass Ejection (usually Sun) CNAM,Conservatoire National des Arts et Métiers CNRS,Centre national de la recherche scientifique CO,Carbon monoxide CO,Carried Over budget COFUND,EU fellowship funding programme CONDOR,"1.5 THz heterodyne receiver (APEX)" CONICA,COudé Near-Infrared CAmera (VLT) CORALIE,Echelle Spectrograph on the 1.2-metre Leonard Euler Swiss telescope CoRoT,COnvection ROtation and planetary Transits (French Satellite) COSMOS,HST survey programme Cou-,Council Document CP,Calibration Programme CPI,Consumer Price Index CRIRES+,Planned upgrade to CRIRES CRIRES,Cryogenic InfraRed Echelle Spectrometer (VLT) CSV,Commissioning and Science Verification CTA,Cherenkov Telescope Array CTA-S,Cherenkov Telescope Array South CTAO,Cherenkov Telescope Array Observatory CUBES,Cassegrain U-band Brazilian ESO Spectrograph CuRe,Fast wavefront reconstruction algorithms for XAO with pyramid WFS CuReD,Fast wavefront reconstruction algorithms for XAO with pyramid WFS with pre-processing DC,Direct Current DDS,Data DistributIOn middleware for SPARTA DDT,Director’s Discretionary Time DFG,Deutsche Forschungsgemeinschaft DFS,(VLT) Data Flow System DG,Director General DIG,Deep Imaging Group (Vitacura) DL,Delay Line (VLTI) DMO,Data Management and Operations Division DMS,Dome and Main Structure DRS,"DRS, formerly Boeing, detector manufacturer" DSC,Directorate for Science DSM,Deformable Secondary Mirror DSO,Department of Science Operations (ALMA) eAPD,electron Avalanche Photodiode Detector EASC,European ALMA Support Centre EC,European Commission ECRI,European Conference on Research Infrastructures EFOSC2,ESO Faint Object Spectrograph and Camera (v.2) EIB,European Investment Bank EIROforum,Organisation consisting of the seven largest scientific European international organisations devoted to fostering mutual activities ELT,Extremely Large Telescope EM&P,"Journal, Earth, Moon, and Planets" EMAC,ELT Management Advisory Committee EMBL,European Molecular Biology Laboratory (Germany) EMMI,ESO Multi-Mode Instrument (NTT) ePOD,education and Public Outreach Department ERC,European Research Council ERIS,Enhanced Resolution Imager and Spectrograph ERP,Enterprise Resource Planning (Administration software) ESAC,European Science Advisory Committee (for ALMA) ESAC,"European Space Astronomy Centre (ESA, Spain)" ESC,ELT Subcommittee ESE,ELT Science and Engineering ESM,European School Munich ESO,European Organisation for Astronomical Research in the Southern Hemisphere ESOF,Euroscience Open Forum ESON,ESO Science Outreach Network ESPRESSO,Echelle SPectrograph for Rocky Exoplanet- and Stable Spectroscopic Observations ESRC,ELT Standing Review Committee ETF,ELT Technical Facility EVALSO,Enabling Virtual Access to Latin-american Southern Observatories EWASS,European Week of Astronomy and Space Science ExA,"Journal, Experimental Astronomy" ExTrA,"(La Silla) Exoplanets in Transit and their Atmospheres" FC,Finance Committee FDR,Final Design Review FE IPT,"Front-End Integrated Project Team (ALMA)" FE,Front End FEA,Finite Element Analysis FEED,Front-End Engineering Design (ELT) FEIC,Front End Integration Centre (ALMA) FEROS,"Fibre-fed, Extended Range, Échelle Spectrograph (MPG/ESO 2.2-metre)" FIAT,"Facility (for) Infrared Arrays Testing" FITS,Flexible Image Transport System FLAMES,Fibre Large Array Multi Element Spectrograph (VLT) FORS1,FOcal Reducer/low dispersion Spectrograph (VLT)-1 FORS2,FOcal Reducer/low dispersion Spectrograph (VLT)-2 FOS,Faint Object Spectrograph (HST) FP,Fabry-Perot FP6,Sixth EC Framework Programme FP7,Seventh EC Framework Programme FWHM,Full Width at Half Maximum GALACSI,"Ground Atmospheric Layer Adaptive Optics for Spectroscopic Imaging (AOF)" GIRAFFE,Fibre-fed multi-object spectrograph and part of the VLT FLAMES facility GLAO,Ground Layer Adaptive Optics gNLT,Garching Night Log Tool GRAAL,GRound-layer Adaptive optics Assisted by Lasers (AOF) GRAVITY,"AO assisted, two-object, multiple-beam-combiner (VLTI)" GROND,"Gamma-Ray Burst Optical/Near-Infrared Detector (MPG/ESO 2.2-metre)" GTC,Gran Telescopio Canarias GTO,Guaranteed Time for Observation GWh,Gigawatt hours GÉANT,European multi-gigabit computer network for research and education purposes H-LTAO,HARMONI Laser Tomography Adaptive Optics H2020,(EU) Horizon 2020 Programme HARMONI,Proposed first light integral field spectrograph for the ELT HARPS,High Accuracy Radial Velocity Planetary Searcher (3.6-metre) HAWK-I,High Acuity Wide field K-band Imager HCI,Human Computer Interface HIA,Herzberg Institute of Astrophysics (Canada) HIRES,(ELT) HIgh REsolution Spectrograph HODM,High Order Deformable Mirror HST,Hubble Space Telescope HVAC,"Heating, Ventilation and Air Conditioning" IAG,"Institute of Astronomy, Geophysics and Atmospheric Sciences (Brazil)" IAU,International Astronomical Union Icar,"Icarus, Planetary science journal, Planetary science journal" IFS,"Integral Field Spectrograph (SPHERE, ELT)" IFU,Integral Field Unit INAF,Italian National Institute for Astrophysics INRIA,Institut National de Recherche en Informatique et en Automatique IPAG,Institut de Planetologie et d’Astrophysique de Grenoble IPC,"(Chilean) Índice de Precios al Consumidor" IPP,Max-Planck Institute for Plasma Physics (Germany) IPSAS,International Public Sector Accounting Standards IPT,Integrated Product Team (ALMA) IR,Infrared IRAM,Institut de Radioastronomie Millimétrique IRDIS,"InfraRed Dual-beam Imager and Spectrograph (SPHERE, ELT)" IRIS,VLTI Infrared Image Sensor IRLOS,InfraRed Low Order Sensor IRO,International Relations Office ISAAC,Infrared Spectrometer And Array Camera (VLT) ISERD,Israeli inter-ministerial agency for R&D cooperation with Europe ISM,International Staff Member ISS,International Space Station IT,Information Technology ITAR,International Traffic in Arms Regulations ITER,International Thermonuclear Experimental Reactor IVOA,International Virtual Observatory Alliance IVSLA,Istituto Veneto di Scienze ed Arti IYA2009,International Year of Astronomy 2009 JAO,Joint ALMA Observatory JENAM,Joint European and National Astronomy Meeting JUICE,JUpiter ICy moons Explorer JWST,James Webb Space Telescope k,"kilo/1,000" KIDS,(VST) Kilo-Degree Survey KMOS,K-band Multi-Object Spectrograph (VLT) KTS,Klaus Tschira Stiftung Kueyan,VLT Unit Telescope 2 LABOCA,Large APEX Bolometer CAmera LAOG,"Laboratoire d'Astrophysique de l'Observatoire de Grenoble" LCS,Local Control System LEO,Low Earth Orbit LFC,Laser Frequency Comb LGS,Laser Guide Star LGSF,Laser Guide Star Facility LMC,Large Magellanic Cloud LMU,Ludwig-Maximilians-Universität München LN2,Liquid nitrogen LOFAR,Low Frequency Array LOPS,Local Optical Phasing Sensor LP,Large Programme LPG,Liquefied Petroleum Gas LPO,"La Silla ­Paranal Observatory" LSM,Local Staff Members LSP,"La Silla ­Paranal Subcommittee" LTAO,Laser Tomography Adaptive Optics LVSM,Large Visible Sensor Module M#,"Mirror #" M,"million/1,000,000" MACAO,Multiple Application Curvature Adaptive Optic MACCON,Motion controller manufacturer MAD,Multi-conjugate Adaptive optics Demonstrator MAORY,(ELT) Multi-conjugate Adaptive Optics RelaY mas,milliarcseconds MASCOT,Mini All-Sky Cloud Observation Tool (Paranal) MATISSE,Multi AperTure mid-Infrared SpectroScopic Experiment (VLTI) MCAO,Multi-Conjugate Adaptive Optics Melipal,VLT Unit Telescope 3 MELT,Minuscule ELT MENLO systems,Optical equipment manufacturer MERAC,Mobilising European Research in Astrophysics and Cosmology MERIL,Mapping the European Research Infrastructure Landscape METIS,Mid-infrared ELT Imager and Spectrograph MICADO,Adaptive optics imaging camera (ELT) MIDI,Mid-infrared Interferometric Instrument (VLTI) MIM,"Museo Interactivo Mirador, Santiago" mmVLBI,Millimeter Very Long Baseline Interferometry Mn,"Mirror #n" MNRAS,"Journal, Monthly Notices of the Royal Astronomical Society" MOAO,Multiple-Object Adaptive Optics MOONS,Multi Object Optical and Near-infrared Spectrograph (VLT third generation) MOS,(ELT) Multi-Object Spectroscopy MOSAIC,"(ELT) Multi-Object Spectrograph (Multi-Object Spectrograph for Astrophysics, Intergalactic medium studies and Cosmology)" MOSFIRE,Near-infrared multi-object spectrograph (Keck) MPA,Max Planck Institute for Astrophysics MPE,Max Planck Institute for Extraterrestrial Physics MPG,Max-Planck-Gesellschaft MPIA,Max Planck Institute for Astronomy MPIfR,Max-Planck Institute for Radioastronomy (Germany) MS,Member State(s) MTM,"MT Mechatronics (European company of high technology, engineering and maintenance services)" MUSE,Multi Unit Spectroscopic Explorer (VLT) NACO,NAOS-CONICA (VLT) NAOJ,National Astronomical Observatory of Japan NAOMI,Adaptive optics system for the ATs (VLTI) NAOS,Nasmyth Adaptive Optics System (VLT) NASA,National Aeronautics and Space Administration NAV,Navision NDF,Non-Deliverable Forward Agreement NEAR,New Earths in the Alpha Cen Region experiment NEO,Near-Earth Object NewA,"Journal, New Astronomy" NewAR,"Journal, New Astronomy Reviews" NFM,Narrow Field Mode NGC,New General Catalogue NGC,New General detector Controller NGSD,"Proposed large natural/laser guide star WFS detector (ELT)" NGTS,Next Generation Transit Survey NINS,National Institutes of Natural Sciences NIRPS,(NNT) Near Infra Red Planet Searcher NOVA,The Netherlands Research School for Astronomy (Nederlandse Onderzoekschool voor Astronomie) NRAO,National Radio Astronomy Observatory NSF,National Science Foundation NTT,New Technology Telescope NUVA,Network for UltraViolet Astrophysics OAA,Arcetri Astrophysical Observatory OBAMA,Optical Bidule for Aberration Measurement on the ATs OCA-NICE,Cote d’Azur Observatory (Observatoire de la Cote d’Azur) ODG,Office of the Director General OECD,Organisation for Economic Co-operation and Development OmegaCAM,Optical Camera for the VST OPC,Observing Programmes Committee OPO,Observing Programmes Office OPTICON,Optical Infrared Coordination Network for Astronomy OSF,ALMA Operations Support Facilities OSO,Onsala Space Observatory OT,Observing Tool OTS,Operations Technical Support P&SS,"Journal, Planetary and Space Science" P2PP,Peer to Peer Protocol P86,Observing Period 86 P87,Observing Period 87 PA,Product Assurance PAC,Provisional Acceptance Chile PACMAN,Fringe tracker for PRIMA (VLTI) PAE,Provisional Acceptance Europe PARLA,"PAranal Raman Laser, replacement for PARSEC (VLTI)" PARSEC,Sodium line laser for VLT AO PASJ,"Journal, Publications of the Astronomical Society of Japan" PASP,"Journal, Publications of the Astronomical Society of the Pacific" PDR,Preliminary Design Review PESSTO,Public ESO Spectroscopic Survey of Transient Objects PFS,(ELT) Pre-Focal Station PFS-A,"(ELT) Pre-Focal Station for Nasmyth A" PhD,Doctor of Philosophy PI,Principal Investigator PIO,Public Information Officer PIONIER,VLTI visitor instrument PIP,Paranal Instrumentation Programme PLC,Programmable Logic Controllers (ELT) PMD,Project Management Department PMPD,Performance Management and Professional Development PRIMA,Phase-Referenced Imaging and Micro-arcsecond Astrometry facility (VLTI) PSF,Point Spread Function PTP,Precision Time Protocol Q,Quarter QSO,"Quasi Stellar Object, quasar" QUEST,QUasar Equatorial Survey Team R&D,Research and Development RAB,Reflector Assembly Building RAL,"Rutherford Appleton Laboratory, Didcot (UK)" RCL,Radioastronomy Chajnantor Limitada RedCLARA,Latin American Advanced Networks Cooperation (Academic data network in Latin America) REM,Rapid Eye Mount Telescope (La Silla) REUNA,Red Universitaria Nacional (Academic data network in Chile) RM,Rossiter-McClaughlin (effect) RMN,Reflective Memory Network (VLTI) rms,Root Mean Square SABOCA,Shortwave Apex BOlometer Camera SAC,EURO-VO Science Advisory Committee SAF,Science Archive Facility SAFRAN-REOSC,High performance optics company SAPHIRA,Detector for the GRAVITY wavefront sensor SAXO,SPHERE’S AO system (VLT) SCAO,Single-conjugate adaptive optics SCO,Santiago Central Office (ALMA/ESO Vitacura) SDD,Software Development Division SDSS,Sloan Digital Sky Survey SEPIA,Swedish ESO PI receiver for APEX SHFI,Swedish Heterodyne Facility Instrument SiC,(ELT) SiliconCarbide-mirrorsubstrate SINFONI,Spectrograph for INtegral Field Observations in the Near Infrared (VLT) SKA,Square Kilometer Array SM,Service Mode (observing) SM4,Servicing Mission 4 (HST) SMBH,Supermassive black hole SOFI,SOn oF Isaac (NTT) SOPHIE,Spectrographe pour l’Observation des Phénomènes des Intérieurs stellaires et des Exoplanètes SOXS,(NTT) Son Of X-Shooter SPARTA,Real-time computer for the AOF SPC,Scientific Personnel Committee SPECULOOS,(Paranal) Search for habitable Planets EClipsing ULtra-cOOl Stars SPHERE,Spectro-Polarimetric High-contrast Exoplanet Research instrument (VLT) SPIFFI,SPectrometer for Infrared Faint Field Imaging SPT,South Pole Telescope SSDF,Science Support Discretionary Fund SSED,Software System Engineering Department SSWG,Science Strategy Working Group ST-ECF,Space Telescope European Coordination Facility STC,Scientific Technical Committee STFC,Science and Technology Facilities Council (UK) STRAP,Tip-tilt sensors (VLTI) STScI,Space Telescope Science Institute (USA) sub-mm,submillimetre SUSI2,Superb Seeing Imager 2 (NTT) TAROT,Télescope à Action Rapide pour les Objets Transitoires TAROT-S,Télescopes à Action Rapide pour les Objets Transitoires South TBT,Test-Bed Telescope TEC,Technology Division telbib,ESO library telescope bibliography database TFB,Tunable Filter Bank (ALMA) TIMMI,TIMMI far-infrared camera (ESO 3.6-metre telescope) ToO,Target of Opportunity TRAPPIST,TRAnsiting Planets and PlanetesImals Small Telescope TRR,Test Readiness Review UC,Users Committee UK ATC,UK Astronomy Technology Centre Ultracam,High-speed camera (VLT) UltraVISTA,Ultra-deep near-infrared survey in the COSMOS field UNCOPUOS,United Nations Committee for the Peaceful Uses of Outer Space USM,University Observatory Munich UT,Unit Telescope of the VLT UT1–4,"VLT Unit Telescopes 1–4: Antu, Kueyen, Melipal and Yepun" UV,UltraViolet UVES,UV-Visual Echelle Spectrograph (VLT) VERTEX,"(APEX) VERTEX Antennentechnik GmbH, Duisburg (Germany)" VHS,VISTA Hemisphere Survey VIDEO,VISTA Deep Extragalactic Observations Survey VIKING,VISTA Kilo-degree Infrared Galaxy survey VIMOS,VIsible MultiObject Spectrograph (VLT) VINCI,VLT INterferometer Commissioning Instrument (VLTI) VIPERS,VIMOS Public Extragalactic Redshift Survey VIRCAM,VISTA Infrared Camera VISA,VLTI Sub-Array VISIR,VLT Mid-Infrared Imager Spectrometer VISTA,Visible and Infrared Survey Telescope for Astronomy VLT,Very Large Telescope VLT/I,Very Large Telescope and its Interferometer VLTI,Very Large Telescope Interferometer VLTI-PR#,VLTI projects VM,Visitor Mode (observing) VMC,VISTA survey of the Magellanic Cloud system VO,Virtual Observatory VOP,Virtual Observatory Project Office VPHAS+,"VST Photometric Hα Survey" VSS,Variability Sky Survey VST,VLT Survey Telescope VVDS,VIMOS VLT Deep Survey VVV,ESO public survey VISTA Variables in the Vía Láctea WASP,Wide Angle Search for Planets survey WFCAM,Infrared wide field camera for the UK Infrared Telescope on Mauna Kea WFI,"Wide Field Imager (MPG/ESO 2.2-metre)" WiFi,Wireless Fidelity WVR,Water Vapour Radiometer (ALMA) X-shooter,Wideband ultraviolet-infrared single target spectrograph (VLT) XAO,Extreme adaptive optics XMM-Newton,X-ray Multi-Mirror satellite (ESA) Yepun,VLT Unit Telescope 4 Z-Spec,Millimetre-wave spectrograph (APEX visitor instrument) zCOSMOS,Large Programme to measure 30 000 galaxies in the HST Cosmic Origins field ZIMPOL,"Zurich Imaging Polarimeter (SPHERE, ELT)" ΛCDM,Lambda Cold Dark Matter μm,Micrometre