Term Index (N)

 N3  N7  NA  NB  NC  ND  NE  NF  NG  NH  NI  NL  NM  NN  NO  NP  NR  NS  NT  NU  NV  NW  NY  NZ

• N (nitrogen): metal, N, atomic number 7
• N (nova): white dwarf explosion
• N (particle number): number of particles
• N: see filter designator
• N: see rare designator prefixes
• n (number density): number of objects per volume
• n: see electron orbital
• n: see electron shell
  • particle number: number of particles
• N 103B: supernova remnant in the LMC
• N band: see infrared
  • mid infrared: infrared radiation with wavelengths in the 7.5-25 μm range
• N galaxy: galaxy with bright nucleus and faint surroundings
• Nāmakanui: see James Clerk Maxwell Telescope
• N-body (N-body simulation): simulation of many objects gravitationally-bound to each other
• N-body problem: calculating the paths of gravitationally-interacting celestial objects
  • adaptive refinement tree: algorithm-type for solving n-body problem
  • HERMIT: code to carry out N-body simulations
  • Jacobi integral: method of solving some three-body problems
  • MERCURY: code to carry out N-body simulations
  • N-body simulation: simulation of many objects gravitationally-bound to each other
  • NBODY: code to carry out N-body simulations
  • REBOUND: code to carry out N-body simulations
• N-body simulation: simulation of many objects gravitationally-bound to each other
• n-NSE: see nuclear statistical equilibrium
• N-PDF: see probability density function
• N-point correlation function (N-point function): general term for analyses-techniques of spatial data
• N-point function: general term for analyses-techniques of spatial data
• N30: see N30 Catalog
• N30 Catalog: 1950s catalog collecting proper motion data from older catalogs
• N747NA: see SOFIA
• N₅₀₀: see cluster radius
• N_A (Avogadro's number): number of hydrogen atoms per gram
  • ideal gas law: relates pressure, temperature, and volume
• N_eff: see neutrino
• N_He: see particle number
• N_HI: see particle number
• n_s: see Lambda-CDM model
• Na (sodium): metal, Na, atomic number 11
• Na: see rare designator prefixes
• NAB: see rare designator prefixes
• nabla: see gradient
• NACA: see NASA
• NACO: see European Southern Observatory Very Large Telescope
• nadir: see zenith
• NAI (NASA Astrobiology Institute): former research funding and coordination organization
• NAIC (Arecibo Observatory): former large 305 m radio telescope in Puerto Rico
• naked singularity: see gravitational singularity
  • law of cosmic censorship: a singularity cannot be observed
• naked T-Tauri star: see T-Tauri star
• Namaka: see Haumea
• Namibia
• Africa Millimetre Telescope: planned 15 m radio telescope array in Namibia
• High Energy Stereoscopic System: ground gamma-ray telescope array
• NAMN (North American Meteor Network): former group of amateurs with an interest in meteors
• Nançay Radio Telescope: large radio telescope in France
  • European Pulsar Timing Array: European collaboration of radio telescopes
• Nancy Grace Roman Space Telescope (Roman Space Telescope): proposed near-infrared space observatory
• NANOGrav: effort to detect gravitational waves through pulsar timing
• nanohertz gravitational waves: size of GWs that pulsar-timing observations might catch
• nanohertz GWs (nanohertz gravitational waves): size of GWs that pulsar-timing observations might catch
• nanolensing: see gravitational microlensing
• nanomaggie: a billionth of an AB magnitude
• nanometer
• angstrom: unit of length 10^-10 meters
• nanosat (nanosatellite): NASA term for a 1-10 kg small satellite
• nanosatellite: NASA term for a 1-10 kg small satellite
• nanotesla: see tesla
• NANTEN: see NANTEN2
• NANTEN-2
• Llano de Chajnantor Observatory: group of observatories on a high plateau of the Atacama Desert
• NANTEN2: millimeter telescope in Chile
  • Atacama Desert: Chilean high-altitude, dry plateau with numerous observatories
• NAOC
• East Asian Observatory: operator of JCMT
• NAOJ (National Astronomical Observatory of Japan): Japanese astronomy organization
  • East Asian Observatory: operator of JCMT
• NAOMI: see European Southern Observatory Very Large Telescope
• NAOMI: see William Herschel Telescope
• Narrabri Observatory
• Narrabri Stellar Intensity Interferometer: 1960s optical interferometer for measuring stellar diameters
• Narrabri Stellar Intensity Interferometer: 1960s optical interferometer for measuring stellar diameters
• narrow band: see passband
• narrow band filter: see passband
• narrow band photometry: see photometry
• narrow emission-line region (narrow line region): AGN region producing narrower lines
  • broad line region: AGN region producing broader lines
• narrow line AGN
• Seyfert galaxy: visible active galaxy
• narrow line region: AGN region producing narrower lines
  • broad line region: AGN region producing broader lines
• narrow-line radio galaxy: see radio galaxy
• narrow-line region
• Seyfert galaxy: visible active galaxy
• narrowband: see bandwidth
• NARVAL
• Zeeman-Doppler imaging: technique for imaging stellar magnetic fields
• NAS (National Acadamy of Sciences): US organization of distinguished scientists
• NAS (Norsk Astronomisk Selskap): Norwegian non-profit association of astronomers
• NASA: includes space-based astronomy research
  • ADEC: NASA unit to coordinate efforts of data archiving and dissemination
  • Advanced Composition Explorer: satellite collecting solar wind and cosmic rays
  • Aeronomy of Ice in the Mesosphere: spacecraft to study upper Earth atmosphere
  • AMES Research Center: NASA lab in silicon valley
  • AMPTE: three spacecraft experimenting on Earth magnetosphere
  • Arcus: X-ray space telescope plan aiming for 2031 launch
  • ARGOS: 1999 technology-research satellite
  • Ariel 5: 1970s X-ray space telescope
  • ARISE: concept for an inflated 25-meter radio telescope in space
  • Armstrong Flight Research Center: NASA aeronautical research center in California
  • Artemis program: NASA's program in development to send people to the moon
  • Astronomical Data Center: 1980s-1990s NASA/Goddard data archive
  • Astronomy Picture of the Day: NASA general education initiative
  • Astrophysics Data and Information Services: perhaps one-time name for NASA ADF or ADS
  • Astrophysics Data Facility: former NASA unit responsible for data from NASA astrophysics missions
  • Astrophysics Data System: online astrophysics bibliography and paper archive
  • ATLAS survey: survey to find NEOs
  • Automated Lunar and Meteor Observatory: ground observatory in Alabama to record Moon-meteoroid impacts
  • AXIS: concept for space X-ray observatory
  • Berkeley Extreme and Far-UV Spectrometer: 1990s UV spectrometer used on two Space Shuttle missions
  • Broad Band X-Ray Telescope: 1990s Astro-1 Space Shuttle X-ray telescope
  • Burst and All Sky Imaging Survey: late 1990s GRB-observer satellite proposal
  • CAESAR: planned space mission to return a sample of a comet
  • Cassini: explorer spacecraft sent to Saturn
  • Catalog of Infrared Observations: collection of infrared observation data from numerous sources
  • Chandra X-ray Observatory: space X-ray telescope
  • CHIPS: small satellite to investigate ISM plasma
  • Combined Release and Radiation Effects Satellite: 1990s satellite investigating Earth's magnetosphere
  • Comet Rendezvous Asteroid Flyby: 1980s/1990s NASA comet exploration plan
  • Compton Gamma Ray Observatory: 1990s space observatory for gamma ray observation
  • CONTOUR: failed 2002 NASA astroid flyby mission
  • Cosmic Background Explorer: 1989 satellite for surveying the CMB
  • Cosmic Dawn Intensity Mapper: NASA concept for space telescope for intensity mapping
  • DAVINCI: planned NASA Venus orbiter
  • Dawn: explorer spacecraft sent to asteroids Vesta and Ceres
  • decadal survey: periodic NASA effort to plan for future astrophysical research
  • Deep Impact: mission to create and observe an impact with a comet
  • Deep Space 1: 1998-2001 mission to fly by asteroid
  • DISCOVR: space weather satellite
  • Dragonfly: Titan flying rover under development
  • Enceladus Life Finder: mission to search for life on Saturn moon Enceladus
  • Enceladus Orbilander: concept for a NASA mission to Enceladus
  • EPOXI: mission using Deep Impact for further exploration
  • ESPEX: concept for a small near-UV/optical space observatory
  • Europa Clipper: NASA Europa space probe launched in 2024
  • Europa Lander: plan for a late 2020s Europa probe landing on the surface
  • EXCLAIM: planned balloon-borne 70-cm telescope with spectrometers
  • Exo-S: a study on the concept of a starshade mission
  • ExoMars: program to search for signs of life on Mars
  • Extreme Ultraviolet Explorer: 1990s ultraviolet space telescope
  • Far Ultraviolet Spectroscopic Explorer: early 2000s space telescope for short-wavelength ultraviolet
  • FARSIDE: concept for a low-frequency radio telescope on the far side of the Moon
  • FarView: concept for a low-frequency radio telescope on the far side of the Moon
  • FAUST: 1990s ultraviolet space telescope used on two Space Shuttle missions
  • Fermi: satellite for studying gamma rays
  • FINESSE: planned space mission for exoplanet spectrography
  • FIRSST: plan for a future far-infrared space telescope
  • Full-sky Astrometric Mapping Explorer: early 2000s proposal for an astrometric space telescope
  • Galaxy Evolution Explorer: observatory-satellite with 50-cm ultraviolet telescope
  • Galileo: circa 1990s space mission to Jupiter
  • Galileo Observatory: 1960s-1970s infrared observatory aircraft
  • Gamow Explorer: proposal for GRB space mission
  • General Coordinates Network: service reporting transients
  • Genesis: NASA spacecraft that returned solar wind particles
  • Goddard Space Flight Center: NASA space research laboratory near Washington D.C.
  • GRAIL: 2011 NASA lunar orbiters to collect gravity data
  • Gravity Probe B: space experiment re GR effects of Earth gravity
  • HabEx: proposed space mission to directly image exoplanets
  • HEAO-1: 1977 X-ray observatory space mission
  • HEAO-2: 1978 X-ray observatory space mission
  • HEASARC: NASA archive of data on high energy astronomy
  • High Energy Transient Explorer: 2000s space multi-band GRB observatory
  • Hitomi: 2016 Japanese space X-ray telescope
  • Hopkins Ultraviolet Telescope: 1990s ultraviolet space telescope used on two Shuttle Shuttle missions
  • Hubble Space Telescope: observatory-satellite with 2.4-meter reflective telescope
  • IMAGE­: satellite mission to study magnetosphere
  • IMAP: future solar science probe
  • InSight: NASA Mars mission to study its interior
  • International Ultraviolet Explorer: 1980s ultraviolet space telescope
  • Interstellar Boundary Explorer: satellite observing the ISM/heliosphere boundary
  • Interstellar Medium Absorption Profile Spectrograph: 1980s/1990s UV spectrometer
  • IPAC: Caltech group to collect and analyze infrared observations
  • IRAS: 1983 satellite that surveyed the sky in infrared
  • IRSA: archive center for infrared data from NASA missions
  • IRTF: Mauna Kea 3-meter infrared telescope
  • IXPE: space observatory with X-ray polarimeters
  • James Webb Space Telescope: 6.5-meter infrared space telescope at L2
  • Jet Propulsion Laboratory: NASA technology research center
  • Juno: mission to Jupiter
  • K2: second Kepler mission that worked around failed equipment
  • Kepler Telescope: space telescope that watched stars for exoplanets
  • Kuiper Airborne Observatory: infrared observatory-plane in the 1980s
  • LAMBDA: NASA archive center re CMB data
  • LCROSS: space probe observing the lunar poles
  • LCRT: concept for a dish radio telescope in a lunar crater
  • LONEOS: survey of near-Earth objects
  • Lucy: space probe to observe Jupiter Trojan asteroids
  • Lunar Prospector: NASA 1998 lunar orbiter
  • Lunar Reconnaissance Orbiter: space probe orbiting the Moon
  • LUVOIR: plan for a space-based telescope
  • Lynx: concept for space X-ray observatory
  • Magellan: 1980s/1990s Venus probe
  • Magnetospheric Multiscale Mission: four spacecraft making Earth magnetosphere measurements
  • Mars 2020: Mars rover mission currently on Mars after 2021 landing
  • Mars Climate Orbiter: failed Mars 1990s probe
  • Mars Exploration Program Analysis Group: NASA forum to provide input to long-term planning of Mars missions
  • Mars Exploration Rover: mission to Mars with two rovers
  • Mars Global Surveyor: Mars probe launched by NASA in 1996
  • Mars Observer: failed 1992-1993 Mars orbiter mission
  • Mars Odyssey: Mars orbiter launched by NASA in 2001
  • Mars Pathfinder: 1990s mission to Mars with rover
  • Mars Polar Lander: failed 1999 Mars lander mission
  • Mars Reconnaissance Orbiter: Mars probe launched by NASA in 2005
  • Mars Science Laboratory: mission to Mars with rover
  • MAST: archive of data from surveys and missions
  • MAVEN: Mars orbiter to study its atmosphere
  • MDR/SRR: planning step for a NASA mission
  • Medium-class Explorer Program: NASA program for small science spacecraft
  • MESSENGER: Mercury probe launched by NASA in 2004
  • microsatellite: NASA term for a 10-100 kg small satellite
  • MMRTG: power source for space probes
  • nanosatellite: NASA term for a 1-10 kg small satellite
  • NASA Astrobiology Institute: former research funding and coordination organization
  • NASA Deep Space Network: NASA's world-wide radio communication setup
  • NASA Orbital Debris Observatory: 1990s telescope aimed at tracking space junk
  • NEAR Shoemaker: space mission to an asteroid
  • NEAT: survey tracking near-Earth objects
  • NEO Surveyor: planned space observatory to detect and monitor NEOs
  • New Horizons: explorer spaceship sent to Pluto
  • New Worlds Mission: plan for space occulter to facilitate the view of exoplanets
  • NICER: space X-ray mission specifically to view neutron stars
  • NuSTAR: space telescope for high-energy X-rays
  • OpenSpace: visualization software aimed at astrophysical data
  • Orbiting Wide-angle Light Collectors: space mission concept to detect cosmic rays through Earth atmosphere light flashes
  • Origins Space Telescope: concept for 2030s large space IR telescope
  • OSAM-1: prototype space robot for servicing satellites
  • OSIRIS-REx: space mission aiming to return a sample of an asteroid
  • OSO 7: 1970s observatory-satellite for viewing the Sun
  • OSO 8: 1970s observatory-satellite for viewing the Sun
  • Outer Planets Assessment Group: NASA forum to provide input to long-term planning of outer planets missions
  • Parker Solar Probe: space probe investigating solar corona
  • Phoenix: Mars polar-region probe launched by NASA in 2007 with lander
  • Pioneer Venus Orbiter: NASA Venus probe launched 1978
  • PIXIE: satellite-concept to to survey CMB polarization
  • PlanetQuest: NASA publicity name for efforts to find exoplanets and life
  • PRIMA: plan for 2030s NASA 1.8-m FIR space telescope
  • Psyche: space mission on its way to asteroid Psyche
  • PUNCH: 4 microsatellites to observe the Sun
  • ROCKE-3D: rocky-planet-oriented general circulation model
  • Roman Space Telescope: proposed near-infrared space observatory
  • RXTE: space mission to time X-ray variations
  • SALTUS: plan for a future far-infrared space telescope
  • Small Astronomy Satellite 2: 1970s NASA gamma ray space telescope
  • Small Astronomy Satellite 3: 1970s NASA X-ray space telescope
  • Small Explorer Program: NASA program for small science spacecraft
  • small satellite: NASA term for a satellite of 1200 kg or less
  • SOFIA: aircraft-based infrared observatory
  • Solar and Heliospheric Observatory: satellite observing the Sun
  • Solar Dynamics Observatory: 2010 satellite observing the Sun
  • Solar Maximum Mission: 1980s satellite to study the Sun during solar maximum
  • Solar Mesophere Explorer: 1980s Earth atmospheric ozone research satellite
  • Space Interferometry Mission: past space interferometer plan for parallax and exoplanet detection
  • Space Launch System: launch rocket in development, e.g., for future astronomical projects
  • Space Transport System: early NASA plan for a Space-Shuttle-like vehicle
  • SPHEREx: all-sky spectral survey space-mission plan
  • SPICE: plan for a future far-infrared space interferometer
  • Spitzer Space Telescope: retired infrared space telescope
  • STAR-X: plan for a future X-ray space telescope
  • Stardust: space mission that collected and returned comet coma dust
  • STEREO: two-satellite system to observe the Sun
  • STROBE-X: space X-ray telescope plan
  • Submillimeter Wave Astronomy Satellite: submillimeter space telescope operating 1998-2004
  • Suzaku: space X-ray telescope
  • Swift: satellite for studying gamma-ray bursts
  • Table Mountain Observatory: NASA observatory near Los Angeles
  • Terrestrial Planet Finder: plan for space telescopes to find smaller exoplanets
  • THEMIS: set of satellites studying the Earth's magnetic field
  • Thousand Astronomical Units: 1980s plan for space probe to travel 1000 AU over 50 years
  • TIM: planned balloon-borne 2 m telescope and spectrometer
  • TIMED: space probe observing Earth upper atmosphere for solar effects
  • TRACE: former solar observing satellite
  • Tracking and Data Relay Satellite System: NASA satellites used for communication and tracking of space probes
  • Transiting Exoplanet Survey Satellite: observatory-satellite searching for transiting exoplanets
  • Tubingen Ultraviolet Echelle Spectrometer: 1990s UV spectrometer used on two Space Shuttle missions
  • Uhuru: 1970 X-ray space telescope
  • Ultraviolet Imaging Telescope: 1990s ultraviolet space telescope used on two Space Shuttle missions
  • Upper Atmosphere Research Satellite: 1990s spacecraft to observe Earth ozone layer
  • Uranus Orbiter and Probe: concept for mission to Uranus
  • VERITAS: planned NASA Venus orbiter
  • Wide Field Infrared Explorer: partly-failed 1999 infrared satellite
  • Wide-field Infrared Survey Explorer: infrared space telescope aimed at an all-sky survey
  • Wilkinson Microwave Anisotropy Probe: spacecraft that measured variations in the cosmic background radiation
  • WISARD: early Internet-based interface to NASA data
  • Wisconsin Ultraviolet Photo-polarimeter Experiment: 1990s ultraviolet space telescope used on two Shuttle Shuttle missions
  • XRISM: X-ray space telescope launched in 2023
• NASA Astrobiology Institute: former research funding and coordination organization
• NASA Deep Space Network: NASA's world-wide radio communication setup
• NASA DSN (NASA Deep Space Network): NASA's world-wide radio communication setup
• NASA Exoplanet Archive: online database of exoplanets
• NASA Flagship Program
• HabEx: proposed space mission to directly image exoplanets
• NASA Infrared Telescope Facility (IRTF): Mauna Kea 3-meter infrared telescope
• NASA IRTF (IRTF): Mauna Kea 3-meter infrared telescope
• NASA Orbital Debris Observatory: 1990s telescope aimed at tracking space junk
  • Large Zenith Telescope: 6 meter liquid mirror telescope in British Columbia
• NASA Space Science Data Coordinated Archive: NASA archive of flight information and astronomy findings
• NASA Standard Breakup Model: model maintained by NASA of how satellites fragment
• NASA/IPAC Extragalactic Database: a database of galaxies and other objects outside the Milky Way
• NASA/IPAC Infrared Science Archive (IRSA): archive center for infrared data from NASA missions
• NASA747: see SOFIA
• NASDA: see Japan Aerospace Exploration Agency
• NASEM (National Academies of Sciences, Engineering, and Medicine): US collective of three national acadamies
• Nasmyth telescope: type of reflector telescope with secondary and tertiary mirrors
• Nasmyth-Cassegrain telescope (Nasmyth telescope): type of reflector telescope with secondary and tertiary mirrors
• NASTec (International Small Telescope Cooperative): former cooperative of small research telescopes
• NaTeCam: see Tianwen-1
• National Acadamy of Sciences: US organization of distinguished scientists
• National Academies of Sciences, Engineering, and Medicine: US collective of three national acadamies
• National Advisory Committee on Aeronautics: see NASA
• National Aeronautics and Space Administration (NASA): includes space-based astronomy research
• National Astronomical Observatories of China
• East Asian Observatory: operator of JCMT
• National Astronomical Observatory
• SPECULOOS: search for Earth-like exoplanets orbiting nearby dim stars
• National Astronomical Observatory of Japan: Japanese astronomy organization
  • East Asian Observatory: operator of JCMT
  • Subaru Telescope: 8.2-meter telescope in Hawaii
• National Astronomy and Ionosphere Center (Arecibo Observatory): former large 305 m radio telescope in Puerto Rico
• National Bureau of Standards: name of of NIST before 1988
• National Center for Atmospheric Research
• High Altitude Observatory: NCAR unit observing and monitoring the Sun
• Mauna Loa Solar Observatory: solar observatory on Mauna Loa
• National Center for Supercomputer Applications
• Partiview: visualization software aimed at 4D data
• National Geographic Society-Palomar Observatory Sky Survey (Palomar Observatory Sky Survey): 1950s photographic plates from Palomar 48 inch telescope
• National Institute of Standards and Technology: US agency defining standards
• National Oceanic and Atmospheric Administration: US meteorology and oceanography agency
  • SWFO-L1: future NOAA space-weather warning satellite
• National Optical Astronomy Observatory: previous name of US optical astronomy organization
  • Association of Universities for Research in Astronomy: collaboration of universities operating observatories
  • Cerro Tololo Inter-American Observatory: NOIRLab observatory in Chile with Blanco telescope
  • Kitt Peak National Observatory: NOIRLab observatory in Arizona with Mayall telescope
  • Mayall 4m Telescope: 4 meter reflector telescope at Kitt Peak
  • SOAR Telescope: 4.1 m reflector telescope in Chile
  • Víctor M. Blanco Telescope: 4 meter reflector telescope in Chile
  • WIYN 3.5m Telescope: Kitt Peak telescope run by university collaboration and NOIRLab
• National Optical-Infrared Astronomy Research Laboratory (NOIRLab): US optical/infrared astronomy organization
  • Association of Universities for Research in Astronomy: collaboration of universities operating observatories
  • Cerro Tololo Inter-American Observatory: NOIRLab observatory in Chile with Blanco telescope
  • Kitt Peak National Observatory: NOIRLab observatory in Arizona with Mayall telescope
  • Mayall 4m Telescope: 4 meter reflector telescope at Kitt Peak
  • SOAR Telescope: 4.1 m reflector telescope in Chile
  • Víctor M. Blanco Telescope: 4 meter reflector telescope in Chile
  • WIYN 3.5m Telescope: Kitt Peak telescope run by university collaboration and NOIRLab
• National Radio Astronomy Observatory: US radio astronomy organization
• National Radio Quiet Zone: see Green Bank Observatory
  • dark sky: sky with limited light pollution
• National Reconnaissance Office
• Roman Space Telescope: proposed near-infrared space observatory
• National Research Council (Consiglio Nazionale delle Ricerche): Italian national research organization.
• National Science Foundation: US government organization funding scientific research
  • National Optical Astronomy Observatory: previous name of US optical astronomy organization
  • National Radio Astronomy Observatory: US radio astronomy organization
  • NOIRLab: US optical/infrared astronomy organization
  • NSF AST: US government astronomical research funding division
• National Solar Observatory: US government sponsored solar observatory
  • Association of Universities for Research in Astronomy: collaboration of universities operating observatories
• National Space Development Agency: see Japan Aerospace Exploration Agency
• National Space Science Data Center (NASA Space Science Data Coordinated Archive): NASA archive of flight information and astronomy findings
• natural astronomical telescopes: use of an astronomical body as a telescope
• natural broadening: line broadening due to uncertainty principle
• natural broadening: see line broadening
  • damping profile: mathematical shape that models some types of spectral line broadening
  • Lorentzian distribution: probability distribution applicable to some physics phenomena
• natural guide star: see guide star
• natural laser: see coherent light
• natural satellite: see moon
• natural satellites
• solar system object: the Sun, solar system planets, minor planets, comets, and moons
• natural units: see Planck units
• Naval Observatory Merged Astrometric Dataset (NOMAD): astrometric star catalog
• Naval Research Laboratory: US Navy scientific research arm
• Navarro-Frenk-White profile: a dark matter spatial mass distribution function
• Navcam: see Mars Exploration Rover
• Navcams: see Mars Science Laboratory
• Navier-Stokes equations: equations that describe fluid dynamics
  • Reynolds decomposition: mathematical separation of average and fluctuating parts of a quantity
• Navy Optical Interferometer
• optical interferometer: interferometer of visible light
• Navy Precision Optical Interferometer: optical interferometer in Arizona
  • optical interferometer: interferometer of visible light
• Navy Prototype Optical Interferometer (Navy Precision Optical Interferometer): optical interferometer in Arizona
  • optical interferometer: interferometer of visible light
• NB: see rare designator prefixes
• NBODY: code to carry out N-body simulations
• NBODY6: see NBODY
• NBODY7: see NBODY
• NBS (National Bureau of Standards): name of of NIST before 1988
• NC: see Stardust
• NC meteorite: see carbonaceous chondrite
• NCAR
• Coronal Solar Magnetism Observatory: proposed solar observatory
• High Altitude Observatory: NCAR unit observing and monitoring the Sun
• MarsWRF: Mars-oriented general circulation model
• Mauna Loa Solar Observatory: solar observatory on Mauna Loa
• NCE: see chemical equilibrium
• NCSA
• Partiview: visualization software aimed at 4D data
• NDWFS (NOAO Deep Wide-field Survey): survey investigating large scale structure of the universe
  • Boötes Field: moderate size survey field
• Ne (neon): element, Ne, atomic number 10
• NEA: see near-Earth object
  • 2010 TK₇: asteroid that is an Earth Trojan
  • asteroid belt: ring of orbiting planetoids/asteroids
• NEAP (Near Earth Asteroid Prospector): planned space mission to look at NEOs as mining sources
• NEAR (NEAR Shoemaker): space mission to an asteroid
• near earth
• asteroid belt: ring of orbiting planetoids/asteroids
• near Earth asteroid
• 2010 TK₇: asteroid that is an Earth Trojan
• near earth asteroid
• asteroid belt: ring of orbiting planetoids/asteroids
• Near Earth Asteroid Prospector: planned space mission to look at NEOs as mining sources
• Near Earth Asteroid Rendezvous (NEAR Shoemaker): space mission to an asteroid
• near earth object
• NEO Surveyor: planned space observatory to detect and monitor NEOs
• Near Earth Object WISE: see Wide-field Infrared Survey Explorer
• Near Earth Objects Dynamic Site (NEODyS): web service to providing information on NEOs
• Near Earth Objects Information Centre (Spaceguard Centre): UK private observatory dedicated to NEOs
• Near Earth Space Surveillance (NEOSSat): small spacecraft tracking NEOs
• near infrared: electromagnetic radiation in the range of 750-2500 nm
  • 3D-HST: near-infrared survey of 100,000 galaxies by HST
  • BASS: survey of AGNs found by the Swift BAT
  • CIBER: sounding-rocket survey of near-infrared background
  • CorMASS: near-infrared spectrograph
  • DENIS: 1990s southern sky survey of two near-infrared bands
  • GaiaNIR: concept for a Gaia follow-on including NIR astrometry
  • Group Evolution Multiwavelength Study: survey of galaxy groups
  • HARMONI: spectrograph planned for E-ELT
  • I band: passband for near-infrared light
  • JHK photometric system: system to classify stars according to near-infrared colors
  • KMOS: 2-micron spectrograph on ESO VLT
  • KMOS3D: survey of galaxies before to after peak star formation
  • MICADO: camera planned for E-ELT
  • Mimir: multi-function near-infrared instrument on Perkins Telescope
  • MKO photometric system: 2000s system covering near infrared
  • Multi-object Optical and Near-IR Spectrograph: advanced spectrograph under development for VLT
  • Multiwavelength Survey by Yale-Chile: optical/NIR survey of four deep fields
  • optics: science and technology regarding visible light
  • Palomar Testbed Interferometer: near-infrared interferometer experiment
  • R band: band of visible light around 6500 angstroms
  • SIMP: 2000s infrared proper-motion survey
  • SINS: near-infrared study of distant luminous galaxies
  • SPECULOOS: search for Earth-like exoplanets orbiting nearby dim stars
  • SPHEREx: all-sky spectral survey space-mission plan
  • UltraVISTA: near infrared survey using VISTA telescope
  • VLT Survey Telescope: survey telescope located at the VLT site
• Near Infrared Camera (NIRCam): near infrared imager on JWST
• Near Infrared Planet Searcher (NIRPS): near-infrared extension to HARPS spectrograph
• Near Infrared Planet Searcher: see ESO 3.6m Telescope
• Near Infrared Spectrograph (NIRSpec): near infrared spectrograph on JWST
• NEAR Shoemaker: space mission to an asteroid
• near ultraviolet: see ultraviolet
  • optics: science and technology regarding visible light
  • ULTRASAT: future satellite to detect UV transients
• near-Earth asteroid: see near-Earth object
• Near-Earth Asteroid Tracking (NEAT): survey tracking near-Earth objects
  • Nearby Supernova Factory: survey that scanned transient data for supernovae
  • Teegarden's Star: nearby red dwarf
• near-Earth object: object orbiting the Sun that passes close to Earth
  • 101955 Bennu: near-Earth asteroid that is the target of a sample-return mission
  • Pan-STARRS: set of survey telescopes
• Near-Earth Object Camera (NEO Surveyor): planned space observatory to detect and monitor NEOs
• Near-Earth Object Surveillance Mission (NEO Surveyor): planned space observatory to detect and monitor NEOs
• Near-Earth Object Surveillance Satellite (NEOSSat): small spacecraft tracking NEOs
  • CSA: includes astronomical research
• Near-Earth Object Surveyor (NEO Surveyor): planned space observatory to detect and monitor NEOs
• near-Earth objects
• ATLAS survey: survey to find NEOs
• Campo Imperatore Near-Earth Object Survey: survey of near-Earth objects
• Catalina Sky Survey: survey of near-Earth objects
• LINEAR: survey of near-Earth objects
• LONEOS: survey of near-Earth objects
• minimum orbit intersection distance: smallest distance between paths of two orbiting bodies
• minor planet: lesser solar system body without comet characteristics
• Near Earth Asteroid Prospector: planned space mission to look at NEOs as mining sources
• NEAT: survey tracking near-Earth objects
• NEODyS: web service to providing information on NEOs
• Pan-STARRS: set of survey telescopes
• Planet Crossing Asteroid Survey: search for NEOs using small Palomar Schmidt Camera
• solar system object: the Sun, solar system planets, minor planets, comets, and moons
• Southern Observatory for Near Earth Asteroids Research: private telescope tracking NEOs
• Spaceguard Centre: UK private observatory dedicated to NEOs
• SpaceGuard Foundation: private organization to discover and track NEOs
• The Near Earth Space Surveillance Initiative: collaboration to survey NEOs
• Wide-field Infrared Survey Explorer: infrared space telescope aimed at an all-sky survey
• near-earth objects
• Minor Planet Center: organization collecting and organizing minor planet data
• near-Earth supernova: supernova near enough to Earth to affect it
• Near-infrared Echelle for Wide-band Spectroscopy (NEWS): planned near-infrared spectrometer on Discovery Channel Telescope
• near-IR (near infrared): electromagnetic radiation in the range of 750-2500 nm
• near-UV: see ultraviolet
• nearby star
• AD Leonis: active red dwarf
• Alpha Centauri: nearest star system
• Barnard's Star: nearby red dwarf
• Capella: brightest star in Auriga
• Epsilon Eridani: third nearest visible star system in sky
• Epsilon Indi: nearby star system including two brown dwarf companions
• Kapteyn's Star: nearby M dwarf
• Lacaille 9352: red dwarf that is the twelfth nearest star system
• Lalande 21185: nearby red dwarf
• Luhman 16: nearby binary brown dwarf
• Luyten 726-8: nearby binary star system
• Procyon: brightest star in Canis Minor
• Ross 154: nearby red dwarf
• Ross 248: nearby red dwarf
• Scholz's Star: nearby binary star with red dwarf and brown dwarf
• Sirius: brightest star in the sky
• Teegarden's Star: nearby red dwarf
• WISE 0855-0714: nearby brown dwarf
• WISE 1506+7027: nearby brown dwarf
• Wolf 359: nearby red dwarf
• Nearby Supernova Factory: survey that scanned transient data for supernovae
• Nearby Supernova Factory II: see Nearby Supernova Factory
• NEAT: survey tracking near-Earth objects
• NEAT: see James Webb Space Telescope
  • Nearby Supernova Factory: survey that scanned transient data for supernovae
  • Teegarden's Star: nearby red dwarf
• nebula: cloud of dust and gas
  • 30 Doradus: HI region in LMC
  • Anticenter Shell: nebula at edge of Milky Way
  • Antlia SN Remnant: dispersed supernova remnant in the constellation Antlia
  • Barnard's Loop: emission nebula in Orion
  • Carina Nebula: HII region with stars and nebulae of interest
  • cloud: higher-density region of space
  • Crab Nebula: supernova remnant in Taurus
  • Cygnus Loop: supernova remnant in Cygnus
  • Cygnus-X: well-studied massive SF region
  • L483: protostar of interest
  • Nessie: star-forming filament found in the Orion star-forming region
  • NGC 3132: PN of interest in southern sky
  • NGC 346: open cluster in SMC
  • Orion Molecular Cloud Complex: group of molecular clouds with star-forming regions
  • Orion Nebula: easily-observed nebula that includes SF regions
  • Radcliffe wave: wave-shaped string of molecular clouds
  • Rho Ophiuchi Cloud Complex: nebula that is a nearby star-forming region
  • Serpens Cloud: molecular cloud with SF regions
  • Sgr B2: GMC near the galactic center
  • W51: cloud complex radio source
• nebulae
• Atlas of Galactic Nebulae: 1980s catalog of Milky-Way nebulae
• Barnard Catalog: 1919 catalog of dark nebulae
• Caldwell Catalog: small catalog for amateur astronomers as an adjunct to the Messier Catalog
• Catalogue of Galactic Planetary Nebulae: 1967 catalog
• Cederblad Catalog: list of bright nebulae
• COUP: survey of X-ray sources in the Orion Nebula
• Herbig-Haro object: type of glowing nebula near protostars
• Index Catalog: 1895 catalog of galaxies, star clusters, and other nebulae
• Lynds Catalog of Dark Nebulae: 1950s/1960s list of dark nebulae found on Palomar plates
• Lynds Catalogue of Bright Nebulae: 1950s/1960s list of bright nebulae found on Palomar plates
• Messier Catalog: catalog of astronomical objects to avoid when looking for comets
• New General Catalogue: 1888 catalog of galaxies, star clusters, and other nebulae
• Parsamian Nebula Catalog: 1965 list of nebulae
• planetary nebula luminosity function: model used in distance estimation
• pulsar wind nebula: type of nebula generated by a young pulsar
• Strasbourg-ESO Catalog of Galactic Planetary Nebulae: 1992 catalog of 1820 objects
• supernova remnant: nebula of debris resulting from a supernova
• Van Den Bergh Reflection Nebula Catalog: catalog of reflection nebulae found in POSS plates
• Zanstra method: method of determining temperature of a hot star within a nebula
• nebular hypothesis: model positing solar system planets result from a solar disk
  • core accretion model: model for the formation of giant planets
  • gravitational instability model: model for the formation of giant planets
• nebular line (forbidden line): spectral line that quantum mechanics disallows for the most part
• nebular shock: see chondrite
• NED (NASA/IPAC Extragalactic Database): a database of galaxies and other objects outside the Milky Way
• Nederlandse Organisatie voor Wetenschappelijk Onderzoek: Dutch research council
• negative absorption: see emission coefficient
• negative feedback
• dynamical instability: situation where a perturbation makes itself larger
• star formation feedback: mechanisms whereby star formation regulates its own rate
• negative gravity anomaly: see gravity anomaly
• negative redshift (blue shift): shortening of wavelengths due to Doppler effects
• negative-pressure vacuum energy density: see inflation
• NEID: see WIYN 3.5m Telescope
• Neil Gehrels Swift Observatory (Swift): satellite for studying gamma-ray bursts
• NELM: naked eye limiting magnitude
• NEMESIS: see atmospheric model
• NEMO: see KM3NeT
• NEMO-3: see KM3NeT
• NEMP: see carbon star
• NEO (near-Earth object): object orbiting the Sun that passes close to Earth
  • asteroid belt: ring of orbiting planetoids/asteroids
  • Catalina Sky Survey: survey of near-Earth objects
  • NEO Surveyor: planned space observatory to detect and monitor NEOs
  • Pan-STARRS: set of survey telescopes
• NEO Surveyor: planned space observatory to detect and monitor NEOs
• NEOCam (NEO Surveyor): planned space observatory to detect and monitor NEOs
• neodymium
• Ap star: peculiar type of A star
• NEODyS: web service to providing information on NEOs
• NEOIC (Spaceguard Centre): UK private observatory dedicated to NEOs
• neon: element, Ne, atomic number 10
  • neon burning: fusion reaction starting with neon
  • nucleosynthesis: creation of atomic nuclei
  • oxygen burning: fusion reaction starting with oxygen
  • white dwarf: stellar remnant largely of electron degenerate matter
• neon burning: fusion reaction starting with neon
  • magnesium: element, Mg, atomic number 12
  • nucleosynthesis: creation of atomic nuclei
  • oxygen: element, O, atomic number 8
• neon-burning shell: see neon burning
• NEOs
• Minor Planet Center: organization collecting and organizing minor planet data
• solar system object: the Sun, solar system planets, minor planets, comets, and moons
• NEOSM (NEO Surveyor): planned space observatory to detect and monitor NEOs
• NEOSSat: small spacecraft tracking NEOs
  • CSA: includes astronomical research
• NEOWISE: see Wide-field Infrared Survey Explorer
  • NEO Surveyor: planned space observatory to detect and monitor NEOs
• NEP (noise-equivalent power): signal power that equals the noise
• Neptune: outer-most solar system planet
  • ethylene: compound of two carbon and four hydrogen atoms
  • giant planet: planet of more than 10 Earth masses
  • ice giant: planet denser than gas planets and less than rocky planets
  • ring system: disk or set of rings orbiting a planet
  • shepherd moon: small moon affecting outer edge of a planet's ring
  • solar system object: the Sun, solar system planets, minor planets, comets, and moons
  • Triton: Neptune's one significant moon
  • Voyager: space probes to observe planets and the edge of the solar system
• Neptune desert: Neptune-like exoplanets near host star are rare
• Neptune I (Triton): Neptune's one significant moon
• Neptune Trojan: see asteroid belt
• Neptunes: see extra-solar planet
• Neptunian desert (Neptune desert): Neptune-like exoplanets near host star are rare
• NES: see Large Altazimuth Telescope
• NESS (NEOSSat): small spacecraft tracking NEOs
• NESSI (The Near Earth Space Surveillance Initiative): collaboration to survey NEOs
• Nessie: star-forming filament found in the Orion star-forming region
• Nessie Nebula (Nessie): star-forming filament found in the Orion star-forming region
• nested Maclaurin spheroids
• theory of figures: type of model relating a planet's shape to its rotation
• nested sampling: see dynesty
• NESTOR: see KM3NeT
• Netherlands
• ASTRON: Netherlands radio astronomy research organization
• Astronomical Netherlands Satellite: 1970s X-ray/ultraviolet space telescope
• Dwingeloo Obscured Galaxy Survey: radio survey of ZOA for 21-cm lines indicating galaxies
• Nederlandse Organisatie voor Wetenschappelijk Onderzoek: Dutch research council
• Space Research Organization of the Netherlands: national research institution
• Westerbork Synthesis Radio Telescope: radio telescope array of 14 dishes in Netherlands
• Westerhout Radio Survey: 1950s radio survey of the galactic plane
• Netherlands Institute for Radio Astronomy (ASTRON): Netherlands radio astronomy research organization
  • Low-frequency Array: low frequency radio telescope
• Netherlands Organisation for Scientific Research
• ASTRON: Netherlands radio astronomy research organization
• neural network: computer program structure inspired by the brain
  • convolutional neural network: type of image processing software
  • deep learning: description of machine learning using substantial neural networks
  • machine learning: use of programs that extract their algorithms from data
  • U-Net: neural network software for image reconstruction
• neural networks
• symbolic regression: automated model-building by tinkering with formulae
• neuron
• convolutional neural network: type of image processing software
• deep learning: description of machine learning using substantial neural networks
• machine learning: use of programs that extract their algorithms from data
• neural network: computer program structure inspired by the brain
• neutral atom: see state of ionization
  • ion: non-neutral atom or molecule, with missing or extra electrons
• neutral atomic hydrogen: state of hydrogen when sufficiently cool
• neutral current interaction: see weak interaction
• neutral tail: see comet
• neutralino: proposed type of particle that might include WIMPs
  • dark matter: matter in galaxies and galaxy clusters suggested by their gravity
  • PICO experiment: a search for a candidate dark matter particle
• neutrino: light, electrically neutral elementary particle
  • dark matter: matter in galaxies and galaxy clusters suggested by their gravity
  • flavor: subtype of some type of particle
  • lepton: elementary particle with 1/2 integer spin such as electron
  • neutronization: an electron and proton combining to form a neutron
  • particle: very small thing
  • supersymmetry: extension to standard model of particle physics
  • WIMP: proposed particle comprising dark matter
• neutrino astronomy: see neutrino
  • astrophysical neutrino: neutrino from other than Earth or the usual sources
• neutrino cooling: see neutrino
• neutrino decoupling: see decoupling
• neutrino detector (neutrino observatory): device to detect neutrinos
  • solar neutrino unit: unit for the detection rate of neutrino detectors
• Neutrino Ettore Majorana Observatory: see KM3NeT
• neutrino experiment: see neutrino observatory
• Neutrino Extended Submarine Telescope with Oceanographic Research: see KM3NeT
• neutrino family: see neutrino
• neutrino flavor: see neutrino
  • neutrino oscillation: neutrinos regularly morph into another flavor
  • TAMBO: concept for neutrino detector in valley in Peru
• neutrino hotspot: region of sky from which significant neutrinos have been detected
• Neutrino Mediterranean Observatory: see KM3NeT
• neutrino observatory: device to detect neutrinos
  • neutrino: light, electrically neutral elementary particle
  • solar neutrino: neutrino from the Sun
• neutrino oscillation: neutrinos regularly morph into another flavor
  • Kamioka Observatory: Japanese underground particle detector
  • Mikheyev-Smirnov-Wolfenstein effect: effect of matter on neutrino oscillation
  • solar neutrino: neutrino from the Sun
  • tau neutrino: neutrino flavor that becomes a tau particle during interactions
• neutrino point source: see neutrino hotspot
• neutrino species: see neutrino
• neutrino temperature
• cosmic neutrino background: low-energy neutrinos left over from early universe
• neutrinoless beta decay (neutrinoless double beta decay): possible type of rare beta decay
• neutrinoless double beta decay: possible type of rare beta decay
  • CUORE: experiment to sense neutrinoless double beta decay
  • EXO: experiment to detect neutrinoless double beta decay in xenon
  • Sudbury Neutrino Observatory: Canadian underground neutrino detector
• neutrinos
• Baksan Neutrino Observatory: Russian underground particle detector
• Borexino: European underground neutrino observatory
• cosmic neutrino background: low-energy neutrinos left over from early universe
• CUORE: experiment to sense neutrinoless double beta decay
• Deep Underground Neutrino Experiment: neutrino experiment under construction
• EXO: experiment to detect neutrinoless double beta decay in xenon
• IceCube: neutrino detector at the South Pole
• IMB: 1980s neutrino detector
• Kamioka Observatory: Japanese underground particle detector
• KATRIN: experiment to measure neutrino mass
• KM3NeT: neutrino detector under construction in the Mediterranean Sea
• localization: ability to identify location of a transient
• Mikheyev-Smirnov-Wolfenstein effect: effect of matter on neutrino oscillation
• neutrino hotspot: region of sky from which significant neutrinos have been detected
• neutrino observatory: device to detect neutrinos
• neutrino oscillation: neutrinos regularly morph into another flavor
• neutrinoless double beta decay: possible type of rare beta decay
• POEMMA: planned space cosmic-ray neutrino observatory
• Project 8: experiment in development to measure neutrino mass
• PROMETHEUS/VERTEX: hydrodynamic simulation system
• solar neutrino: neutrino from the Sun
• solar neutrino unit: unit for the detection rate of neutrino detectors
• Sudbury Neutrino Observatory: Canadian underground neutrino detector
• TAMBO: concept for neutrino detector in valley in Peru
• tau neutrino: neutrino flavor that becomes a tau particle during interactions
• TXS 0506+056: blazar that is a neutrino source
• Urca process: neutrino-emitting process
• neutron: type of baryon that is stable and has no electric charge
  • baryon: protons, neutrons, and other three-quark particles
  • neutron spectrometer: device determining the energy of received free neutrons
  • nucleon: proton or neutron
  • quark: type of elementary particle incorporated in protons and neutrons
  • quark matter: matter not made of protons and neutrons but of quarks
  • radioactive decay: changes in atomic nuclei that happen over time
  • standard model: model of elementary particles including quarks
  • valley of beta stability: set of isotopes not prone to beta decay
• neutron capture: combination of an atomic nucleus and a neutron
• neutron degeneracy pressure: see electron degeneracy
  • neutron star: stellar remnant consisting entirely of solar masses of neutrons
• neutron degenerate matter: matter made up primarily of neutrons
• neutron degenerate matter: see electron degeneracy
  • degeneracy: general word meaning a violation of normal rules
  • electron degenerate matter: dense matter such as that in white dwarf
• neutron drip: neutrons exiting from nuclei
• neutron emission: see radioactive decay
• neutron heavy: see neutron drip
• neutron lifetime: see neutron capture
• neutron matter (neutron degenerate matter): matter made up primarily of neutrons
• neutron poor: see neutron rich
• neutron rich: more than usual neutrons
• neutron scattering: scattering of neutrons by atomic nuclei
• neutron spectrograph: see neutron scattering
• neutron spectrometer: device determining the energy of received free neutrons
• neutron spectroscopy: see neutron scattering
• neutron star: stellar remnant consisting entirely of solar masses of neutrons
  • Black Widow Pulsar: binary system consisting of a pulsar and small companion
  • GW detection: observed gravitational wave signal recognizable as an astronomical event
  • Hulse-Taylor Binary: binary system consisting of a pulsar and neutron star
  • J1713+0747: binary system with millisecond pulsar and white dwarf
  • PSR 1257+12: pulsar with first discovered planet system
  • PSR B0950+08: young pulsar
  • PSR J2145-0750: binary system consisting of a pulsar and white dwarf
  • SGR 1935+2154: Milky Way SGR generating FRBs
  • SGR J1745-2900: magnetar orbiting the Milky Way SMBH
• neutron star binary: see binary neutron star
• Neutron Star Interior Composition Explorer (NICER): space X-ray mission specifically to view neutron stars
• neutron star kick: see velocity kick
• neutron star matter (neutron degenerate matter): matter made up primarily of neutrons
• neutron star merger: two neutron stars meeting and forming one
• neutron star merger: see binary neutron star
  • GW detection: observed gravitational wave signal recognizable as an astronomical event
  • GW170817: 2017 gravitational wave detection from a neutron star merger
  • standard siren: transient whose gravitational waves indicate a specific distance
• neutron stars
• anomalous X-ray pulsar: X-ray pulsars with no high-mass companion
• binary neutron star: two neutron stars co-orbiting
• compact object: dense astronomical body such as white dwarf or denser
• electron degeneracy: electrons set free of atoms by the Pauli exclusion principle
• GW170817: 2017 gravitational wave detection from a neutron star merger
• high-B radio pulsar: pulsar with a strong magnetic field
• hypermassive neutron star: neutron star massive enough to collapse
• kilonova: transient associated with merging neutron stars
• magnetar: neutron star with a strong magnetic field
• neutron star merger: two neutron stars meeting and forming one
• neutron-star black-hole merger: a neutron star falling into a black hole
• NICER: space X-ray mission specifically to view neutron stars
• pion: first type of meson discovered
• pulsar: type of astronomical body with EMR in regular cycles of seconds or less
• soft gamma repeater: object that produces repeated gamma-ray bursts
• strong-field gravity: gravity much stronger than in the solar system such as near a black hole
• Thorne-Żytkow object: giant star with a neutron star at its center
• tidal tail: string of mass ejected by a tidal forces in a neutron star merger
• Tolman-Oppenheimer-Volkoff limit: maximum mass of a neutron star
• Urca process: neutrino-emitting process
• X-ray burster: neutron star binary producing nova-like bursts
• X-ray pulsar: pulsar producing X-rays from accretion
• neutron-rich NSE: see nuclear statistical equilibrium
• neutron-star black-hole merger: a neutron star falling into a black hole
• neutron-star/black-hole merger
• GW detection: observed gravitational wave signal recognizable as an astronomical event
• neutronization: an electron and proton combining to form a neutron
• neutronization burst: see neutronization
• neutrons from carbon-13: process by which neutrons are freed in the s process
• neutronstar kick
• core collapse supernova: supernova resulting from the collapse of the core of a star
• NeVe: see rare designator prefixes
• New: see Shapley-Ames Catalog
• New Catalogue of Suspected Variable Stars: catalog from latter half of 20th century catalog
• New Frontiers
• CAESAR: planned space mission to return a sample of a comet
• Dragonfly: Titan flying rover under development
• Enceladus Life Finder: mission to search for life on Saturn moon Enceladus
• Juno: mission to Jupiter
• New Horizons: explorer spaceship sent to Pluto
• OSIRIS-REx: space mission aiming to return a sample of an asteroid
• New Frontiers 1 (New Horizons): explorer spaceship sent to Pluto
• New Frontiers 2 (Juno): mission to Jupiter
• New Frontiers 3 (OSIRIS-REx): space mission aiming to return a sample of an asteroid
• New Frontiers 4 (Dragonfly): Titan flying rover under development
  • CAESAR: planned space mission to return a sample of a comet
  • Enceladus Life Finder: mission to search for life on Saturn moon Enceladus
• New Frontiers Program
• NASA: includes space-based astronomy research
• New General Catalogue: 1888 catalog of galaxies, star clusters, and other nebulae
• New general catalogue of double stars within 120° of the North pole. (Aitken Double Star Catalogue): 1932 catalog with both multiple-star systems and non-orbiting double stars
• New General Catalogue of Nebulae and Clusters of Stars (New General Catalogue): 1888 catalog of galaxies, star clusters, and other nebulae
• New Gravitational Wave Observatory: past proposal for space mission to detect gravitational waves
• New Horizons: explorer spaceship sent to Pluto
• New Jersey
• CAPMAP: early 2000s array that surveyed CMB polarization
• New Luyten Two-Tenths Arcsecond Catalog: see Luyten Two-Tenths Arcsecond Catalog
• New Mexico
• Dragonfly Telephoto Array: Canadian compact array of small visible-light telescopes
• EXO: experiment to detect neutrinoless double beta decay in xenon
• Fenton Hill Observatory: New Mexico GRB-oriented astronomical observatory
• Long Wavelength Array: radio telescope in New Mexico
• Milagro: gamma ray telescope using Cherenkov radiation
• MRO Interferometer: optical interferometer in New Mexico
• RAPTOR: automated array of telescopes to uncover and track transients
• Sloan 2.5m Telescope: telescope for SDSS in New Mexico
• Very Large Array: radio telescope in New Mexico
• New Mexico Skies
• Dragonfly Telephoto Array: Canadian compact array of small visible-light telescopes
• new Moon
• earthshine: reflected and emitted electromagnetic radiation from Earth
• New Robotic Telescope: see Liverpool Telescope
• New Robotic Telescope: see Roque de los Muchachos Observatory
• New Solar Telescope: see Big Bear Solar Observatory
• New South Wales
• SkyMapper: automated 1.35 m optical telescope in Australia
• New Technology Telescope: 3.58-meter reflector telescope in Chile
  • La Silla Observatory: Atacama-desert observatory run by ESO
  • WINERED: near-infrared non-cryogenic spectrograph
• New Worlds Imager (New Worlds Mission): plan for space occulter to facilitate the view of exoplanets
• New Worlds Mission: plan for space occulter to facilitate the view of exoplanets
• New Worlds Observer (New Worlds Mission): plan for space occulter to facilitate the view of exoplanets
• New X-ray Telescope (Hitomi): 2016 Japanese space X-ray telescope
• New Zealand
• MOA: search for microlensing events
• NEWS: planned near-infrared spectrometer on Discovery Channel Telescope
• newton: see joule
  • tesla: unit of magnetic flux density
• Newton's first law: see Newton's laws
• Newton's law of gravitation: see Newton's laws
• Newton's laws: physical laws of dynamics and gravitation
  • celestial mechanics: study of forces and motion of celestial objects
• Newton's laws of motion: see Newton's laws
• Newton's second law: see Newton's laws
• Newton's third law: see Newton's laws
• Newtonian gravitational constant (gravitational constant): indicates how much pull between two masses
• Newtonian gravitational field: see gravitational field
• Newtonian gravity: see Newton's laws
  • Birkhoff's theorem: shows GR qualities of a spherically-symmetric mass
  • gravity: theory that mass attracts
  • parameterized post-Newtonian formalism: method of approximating GR-based gravity from Newtonian gravity
• Newtonian mechanics: see Newton's laws
  • mechanics: the science of forces and motions
  • post-Newtonian formalism: method of approximating GR-based mechanics from Newtonian mechanics
  • quantum mechanics: modern mechanical theory of small things, on the scale of atoms
• Newtonian telescope: type of reflector telescope
• nEXO: see EXO
• NeXT (Hitomi): 2016 Japanese space X-ray telescope
• Next Generation Space Telescope (James Webb Space Telescope): 6.5-meter infrared space telescope at L2
• Next Generation Very Large Array: planned radio telescope array as a follow-on to ALMA and the Jansky VLA
• next-EXO: see EXO
• Next-generation Transit Survey (NGTS): survey of transits from Chile
• NEXTSat: see Autonomous Space Transport Robotic Operations
• NF1 (New Horizons): explorer spaceship sent to Pluto
• NF2 (Juno): mission to Jupiter
• NF3 (OSIRIS-REx): space mission aiming to return a sample of an asteroid
• NF4 (Dragonfly): Titan flying rover under development
  • CAESAR: planned space mission to return a sample of a comet
  • Enceladus Life Finder: mission to search for life on Saturn moon Enceladus
• NFI: see PUNCH
• nFLASH: see Atacama Pathfinder Experiment
• NFW profile (Navarro-Frenk-White profile): a dark matter spatial mass distribution function
• NG (non-Gaussian): something requiring adjustment from the Gaussian function
• NG: see NGTS
• NGC (New General Catalogue): 1888 catalog of galaxies, star clusters, and other nebulae
• NGC 104 (47 Tucanae): bright globular cluster
• NGC 1052: elliptical galaxy with ultra diffuse dwarf satellites
• NGC 1052 Group: see NGC 1052
• NGC 1052-DF2: see NGC 1052
  • dark-matter-free galaxy: galaxy showing signs of no dark matter
• NGC 1052-DF4: see NGC 1052
• NGC 1064
• neutrino hotspot: region of sky from which significant neutrinos have been detected
• NGC 1068 (Messier 77): easily-observed spiral galaxy
• NGC 1275: see Perseus Cluster
• NGC 1344
• shell galaxy: galaxy with one or more surrounding layers of brightness
• NGC 147
• satellite galaxy: galaxy that orbits a larger galaxy
• NGC 1555
• T Tauri: variable star taken as example of young star
• NGC 1600: elliptical galaxy with large supermassive black hole
• NGC 185
• satellite galaxy: galaxy that orbits a larger galaxy
• NGC 1866: globular cluster of interest in the LMC
• NGC 1952 (Crab Nebula): supernova remnant in Taurus
• NGC 1976 (Orion Nebula): easily-observed nebula that includes SF regions
• NGC 2070
• 30 Doradus: HI region in LMC
• NGC 224 (Andromeda): spiral galaxy in the Local Group
• NGC 2363: low-metallicity SF region
• NGC 2366: see NGC 2363
• NGC 253: spiral galaxy 11 million light-years away
• NGC 2682 (Messier 67): old open cluster in Cancer
• NGC 2736: see Vela supernova remnant
• NGC 2770: spiral galaxy that has shown a number of supernovae
• NGC 3031
• Council of Giants: twelve large galaxies surrounding the Local Group
• NGC 3034 (M82): nearby starburst galaxy
  • Council of Giants: twelve large galaxies surrounding the Local Group
• NGC 3132: PN of interest in southern sky
• NGC 3201: globular cluster in which a black hole has been identified
• NGC 3314: a pair of galaxies aligned with us
• NGC 3372 (Carina Nebula): HII region with stars and nebulae of interest
• NGC 346: open cluster in SMC
• NGC 4258 (Messier 106): spiral galaxy with maser
• NGC 4321 (Messier 100): easily-observed spiral galaxy
• NGC 4374 (Messier 84): elliptical galaxy with jets
• NGC 4486 (M87): supergiant elliptical galaxy in local universe
• NGC 4594 (Sombrero Galaxy): striking spiral galaxy with very large bulge
• NGC 4736
• Council of Giants: twelve large galaxies surrounding the Local Group
• NGC 4826 (M64): nearby dusty galaxy
  • Council of Giants: twelve large galaxies surrounding the Local Group
• NGC 4945
• Council of Giants: twelve large galaxies surrounding the Local Group
• NGC 4993: see GW170817
• NGC 5128 (Centaurus A): nearby radio galaxy
  • Council of Giants: twelve large galaxies surrounding the Local Group
• NGC 5139 (Omega Centauri): large globular cluster
• NGC 5194 (Whirlpool Galaxy): easily-observed spiral galaxy
• NGC 5236
• Centaurus A: nearby radio galaxy
• Council of Giants: twelve large galaxies surrounding the Local Group
• NGC 5457 (Pinwheel Galaxy): easily-observed spiral galaxy
• NGC 5548
• gas streamer: stream of gas
• NGC 5866 (Spindle Galaxy): disk galaxy for which we have an edge-on view
• NGC 598 (Triangulum Galaxy): small spiral galaxy in the Local Group
• NGC 628 (Messier 74): easily-observed spiral galaxy
• NGC 6822
• Cerro Tololo Inter-American Observatory: NOIRLab observatory in Chile with Blanco telescope
• NGC 6946: face-on spiral galaxy
• NGC 6960: see Cygnus Loop
• NGC 6992: see Cygnus Loop
• NGC 6995: see Cygnus Loop
• NGC 7078 (Messier 15): globular cluster with collapsed core
• NGC 7317: see Stephan's Quintet
• NGC 7318A: see Stephan's Quintet
• NGC 7318B: see Stephan's Quintet
• NGC 7319: see Stephan's Quintet
• NGC 7320: see Stephan's Quintet
• NGC 7331: spiral galaxy without a bar
• NGC 7469: spiral galaxy with AGN outflow
• NGC 7727: irregular galaxy with two SMBHs
• NGC2000.0: see New General Catalogue
• NGCFHT: see Canada-France-Hawaii Telescope
• ngEHT: see Event Horizon Telescope
• NGIMS: see MAVEN
• NGO (New Gravitational Wave Observatory): past proposal for space mission to detect gravitational waves
• NGPS: see Hale Telescope
• NGS: see Galaxy Evolution Explorer
• NGS: see guide star
• NGS-POSS (Palomar Observatory Sky Survey): 1950s photographic plates from Palomar 48 inch telescope
• NGST (James Webb Space Telescope): 6.5-meter infrared space telescope at L2
• NGTS: survey of transits from Chile
  • Paranal Observatory: ESO Atacama observatory with ESO VLT
• ngVLA (Next Generation Very Large Array): planned radio telescope array as a follow-on to ALMA and the Jansky VLA
  • National Radio Astronomy Observatory: US radio astronomy organization
• NH: see rare designator prefixes
• NH₃ (ammonia): particular compound of nitrogen and hydrogen
• NHI: see particle number
• NHICAT: see HIPASS
• NHO (Roque de los Muchachos Observatory): observatory at La Palma in the Canary Islands
• NI
• nitrogen: metal, N, atomic number 7
• Ni (nickel): metal, Ni, atomic number 28
• Nice model: model of the evolution of the solar system
  • late heavy bombardment: time after solar system planet-formation when many impacts occurred
• NICER: space X-ray mission specifically to view neutron stars
• Nicholas U. Mayall Telescope (Mayall 4m Telescope): 4 meter reflector telescope at Kitt Peak
  • National Optical Astronomy Observatory: previous name of US optical astronomy organization
• NICI: see Gemini Observatory
• nickel: metal, Ni, atomic number 28
  • r-process: synthesis of elements through neutron capture faster than beta decay
• nickel-56: see nickel
• nickel-58: see nickel
• nickel-62: see nickel
• NICMOS: see Hubble Space Telescope
  • GOODS NICMOS Survey: survey with HST NICMOS instrument of galaxies in GOODS fields
• NICMOS3
• Hawaii K-band Galaxy Survey: near-infrared survey of a selection of fields
• NICS: see Telescopio Nazionale Galileo
• NIFS: see Gemini Observatory
• night sky
• light pollution: light from cities that interferes with astronomical observation
• visible light: electromagnetic radiation that our eyes can sense
• nightglow (airglow): glow from a planet's atmosphere
• NIHTS: see Lowell Discovery Telescope
• NII
• nitrogen: metal, N, atomic number 7
• NIII
• nitrogen: metal, N, atomic number 7
• NIKA: see IRAM 30m Telescope
• NIKA2: see IRAM 30m Telescope
• Nili Fossae: region of grabens on Mars
• NIMS: see Galileo
• NIR (near infrared): electromagnetic radiation in the range of 750-2500 nm
• NIR: see Southern African Large Telescope
• NIR3: see Hayabusa2
• NIRC: see Keck Observatory
• NIRC-2: see Keck Observatory
• NIRC2
• PALMS: survey to find exoplanets for direct imaging
• NIRCam: near infrared imager on JWST
• NIRCam: see James Webb Space Telescope
  • grism: combination of a grating and a prism
• NIRES: see Keck Observatory
• NIRI: see Gemini Observatory
• NIRIS: see Big Bear Solar Observatory
• NIRISS: see James Webb Space Telescope
• NIRISS SOSS: see James Webb Space Telescope
• NIRPS: near-infrared extension to HARPS spectrograph
• NIRPS: see ESO 3.6m Telescope
• NIRSPEC: see Keck Observatory
  • Keck Planet Imager and Characterizer: extreme AO upgrade under development for Keck
• NIRSpec: near infrared spectrograph on JWST
• NIRSpec: see James Webb Space Telescope
• NIRSpec G395: see James Webb Space Telescope
• NIRWALS: see Southern African Large Telescope
• NIS: see NEAR Shoemaker
• NISP: see Euclid
• NIST (National Institute of Standards and Technology): US agency defining standards
• NISTAR: see DISCOVR
• nitrite: ion of a nitrogen atom and two oxygen atoms with extra electron
• nitrite salt
• nitrite: ion of a nitrogen atom and two oxygen atoms with extra electron
• nitrogen: metal, N, atomic number 7
  • amine: type of compound containing nitrogen
  • ammonia: particular compound of nitrogen and hydrogen
  • HCO⁺: ionized compound of hydrogen, carbon, and oxygen, one atom each
  • hydrogen cyanide: compound of hydrogen, carbon, and nitrogen, one atom each
  • nitrite: ion of a nitrogen atom and two oxygen atoms with extra electron
• nitrogen dioxide
• nitrite: ion of a nitrogen atom and two oxygen atoms with extra electron
• nitrogen-enhanced metal-poor star: see carbon star
• nitrogen-rich Wolf-Rayet: see Wolf-Rayet star
• NIVR
• IRAS: 1983 satellite that surveyed the sky in infrared
• Nix: see Pluto
• NLAGN: see active galactic nucleus
  • Seyfert galaxy: visible active galaxy
• NLR (narrow line region): AGN region producing narrower lines
• NLR: see NEAR Shoemaker
  • broad line region: AGN region producing broader lines
  • Seyfert galaxy: visible active galaxy
• NLRG: see radio galaxy
• NLTE: see local thermodynamic equilibrium
• NLTT: see Luyten Two-Tenths Arcsecond Catalog
• nm
• angstrom: unit of length 10^-10 meters
• NML: see rare designator prefixes
• NMS: see Giotto
• NN (neural network): computer program structure inspired by the brain
• NN-EXPLORE
• WIYN 3.5m Telescope: Kitt Peak telescope run by university collaboration and NOIRLab
• no-hair theorem: proposition that a black hole only has mass, rotation, and charge
• No-U Turn Sampler: see PyMC
• NO₂
• nitrite: ion of a nitrogen atom and two oxygen atoms with extra electron
• NO₂^- (nitrite): ion of a nitrogen atom and two oxygen atoms with extra electron
• NOAA (National Oceanic and Atmospheric Administration): US meteorology and oceanography agency
  • MarsWRF: Mars-oriented general circulation model
  • SWFO-L1: future NOAA space-weather warning satellite
• NOAO (National Optical Astronomy Observatory): previous name of US optical astronomy organization
  • Association of Universities for Research in Astronomy: collaboration of universities operating observatories
  • Cerro Tololo Inter-American Observatory: NOIRLab observatory in Chile with Blanco telescope
  • Kitt Peak National Observatory: NOIRLab observatory in Arizona with Mayall telescope
  • Mayall 4m Telescope: 4 meter reflector telescope at Kitt Peak
  • SOAR Telescope: 4.1 m reflector telescope in Chile
  • Víctor M. Blanco Telescope: 4 meter reflector telescope in Chile
  • WIYN 3.5m Telescope: Kitt Peak telescope run by university collaboration and NOIRLab
• NOAO Deep Wide-field Survey: survey investigating large scale structure of the universe
• NOAO Deep-Wide-Field Survey
• Boötes Field: moderate size survey field
• NOAO Source Catalog: catalog compiled from NOAO public data
• noble gas
• mass spectrometer: device to determine the mass of molecules in a mixture
• nodding: see chopping mirror
• NODO (NASA Orbital Debris Observatory): 1990s telescope aimed at tracking space junk
• NOEMA (Northern Extended Millimeter Array): large radio telescope array under construction in Europe
  • PHIBSS: survey of CO in distant galaxies
• NOFS: see USNO
  • USNO Twin Astrograph: USNO astrograph deployed in 1970
• NOIRLab: US optical/infrared astronomy organization
  • Association of Universities for Research in Astronomy: collaboration of universities operating observatories
  • Cerro Tololo Inter-American Observatory: NOIRLab observatory in Chile with Blanco telescope
  • Kitt Peak National Observatory: NOIRLab observatory in Arizona with Mayall telescope
  • Mayall 4m Telescope: 4 meter reflector telescope at Kitt Peak
  • SOAR Telescope: 4.1 m reflector telescope in Chile
  • Víctor M. Blanco Telescope: 4 meter reflector telescope in Chile
  • WIYN 3.5m Telescope: Kitt Peak telescope run by university collaboration and NOIRLab
• noise
• parts per million: method of expressing a small ratio
• time-ordered data: observation data arranged by the time it was received
• noise power
• noise temperature: a measure of noise in electronic devices
• noise temperature: a measure of noise in electronic devices
  • antenna temperature: a type of measure of the noise introduced by an antenna
  • thermal noise: noise inherent in electronic component warmer than absolute zero
• noise-equivalent power: signal power that equals the noise
• NOMAD: astrometric star catalog
• NOMAD: see Trace Gas Orbiter
• NOMAD1: see NOMAD
• NOMIC: see Large Binocular Telescope
• non chemical equilibrium: see chemical equilibrium
• non local thermodynamic equilibrium: see local thermodynamic equilibrium
• non-baryonic matter: see baryonic matter
  • baryon: protons, neutrons, and other three-quark particles
  • dark matter: matter in galaxies and galaxy clusters suggested by their gravity
• non-carbonaceous chondrite: see carbonaceous chondrite
• non-CE: see chemical equilibrium
• non-condensing gas: see biosignature
• non-Gaussian: something requiring adjustment from the Gaussian function
• non-Gaussianity: see non-Gaussian
• non-inertial reference frame: see inertial reference frame
• non-integrated Sachs-Wolfe effect: see Sachs-Wolfe effect
• non-LTE: see local thermodynamic equilibrium
  • CMFGEN: RT code designed to handle significant stellar wind
• non-metal
• helium: non-metallic element, He, atomic number 2
• hydrogen: most prominent element, atomic number 1
• non-Planckian: see black-body radiation
• non-Planckian: see thermal emission
• non-relativistic speed: see relativistic speed
• non-relativistic speed: see relativity
• non-standard cosmologies (alternative cosmologies): cosmological models other than Big Bang/Lambda-CDM
• non-thermal: regarding radiation other than black-body
• non-thermal emission: EMR not due to a body's heat
• non-thermal escape: see atmospheric escape
• non-thermal radiation (non-thermal emission): EMR not due to a body's heat
• nonbaryonic matter: see baryonic matter
  • baryon: protons, neutrons, and other three-quark particles
• noncollisional: see stellar dynamics
• nondimensionalization: manipulation of an equation to remove units
• nonlinear GW memory: see gravitational-wave memory
• nonparametric model: model developed avoiding assumptions regarding a basic structure
• nonparametric statistics: see nonparametric model
• nonsingular black hole model: see black hole model
• Nordic Optical Telescope: see Roque de los Muchachos Observatory
• Norma Arm: see spiral arm
• Norma Cluster
• ESO 137-001: barred spiral galaxy in the Abell 3627 cluster
• Norma-Cygnus Arm: see spiral arm
• normal color index: see color index
• normal distribution: familiar probability distribution with bell curve shape
  • Gaussian function: function producing the bell curve
  • Lorentzian distribution: probability distribution applicable to some physics phenomena
  • Maxwell-Boltzmann distribution: distribution of velocities of gas particles
  • photon noise: variation in light measurement due to its quantum nature
  • sigma: indication of the confidence level of an experiment
  • spectral resolution: measure of a spectrograph's ability to resolve features of the spectrum
• normal elastic thickness: see elastic thickness
• normal mode: resonant surface waves in seismology
• normal mode (eigenmode): vibration mode of an oscillator where all parts move at the same frequency
• normalization constant: see probability density function
• normalization constant: see probability mass function
• normalized PDF: see probability density function
• normalized PMF: see probability mass function
• normalizing constant: see probability density function
• normalizing constant: see probability mass function
• Norsk Astronomisk Selskap: Norwegian non-profit association of astronomers
• North American Meteor Network: former group of amateurs with an interest in meteors
• North American Nanohertz Observatory for Gravitational Waves (NANOGrav): effort to detect gravitational waves through pulsar timing
• North American Small Telescope Cooperative (International Small Telescope Cooperative): former cooperative of small research telescopes
• north galactic pole (galactic north): determination of the more northern direction of the Milky Way's axis
• north node: see orbital element
• north polar sequence: set of stars previously used to define magnitudes
• Northern Cross Radio Telescope
• Bologna Survey of Radio Sources: 1970s-1980s radio survey
• transit telescope: telescope able to shift aim up/down but not horizontally
• Northern Extended Millimeter Array: large radio telescope array under construction in Europe
  • PHIBSS: survey of CO in distant galaxies
• Northern Hemisphere Observatory (Roque de los Muchachos Observatory): observatory at La Palma in the Canary Islands
• northern lights: see aurora
• northern zone of avoidance: see zone of avoidance
• Norway
• Norsk Astronomisk Selskap: Norwegian non-profit association of astronomers
• Norwegian Astronomical Society (Norsk Astronomisk Selskap): Norwegian non-profit association of astronomers
• NOT: see Roque de los Muchachos Observatory
• Nova: see nova
• nova: white dwarf explosion
  • supernova impostor: extreme stellar explosion that does not destroy the star
• Nova Delphini 2013 (V339 Delphini): 2013 nova showing lithium synthesis
• nova eruption: see nova
• nova remnant: see supernova remnant
• NP: see black-body radiation
• NP: see thermal emission
• NPDF: see probability density function
• NPM1G: see rare designator prefixes
• NPOI (Navy Precision Optical Interferometer): optical interferometer in Arizona
  • optical interferometer: interferometer of visible light
• NPS (north polar sequence): set of stars previously used to define magnitudes
• NR (numerical relativity): solving GR-sensitive problems with numerical methods
• NRAL (Jodrell Bank Observatory): radio observatory in England
• NRAO (NRAO Catalog): 1960s follow-up to Cambridge radio surveys
• NRAO (National Radio Astronomy Observatory): US radio astronomy organization
  • Atacama Large Millimeter Array: advanced millimeter-telescope array in Chile
  • Cherenkov Telescope Array: ground gamma-ray telescope array in development
  • Giant Metrewave Radio Telescope: large radio interferometer in India
  • GUPPI: radio-telescope back-end aimed at processing pulsar data
  • MOJAVE: program to monitor AGN jet radio brightness and polarization
  • Next Generation Very Large Array: planned radio telescope array as a follow-on to ALMA and the Jansky VLA
  • NRAO VLA Sky Survey: 1990s microwave survey of 82% of the sky
  • Very Large Array: radio telescope in New Mexico
  • Very Long Baseline Array: radio interferometer stretching 8000 km
• NRAO Catalog: 1960s follow-up to Cambridge radio surveys
• NRAO Seven-beam Receiver
• Green Bank 6-cm Radio Source Catalog: catalog of from 1980s northern-hemisphere radio survey
• Parkes-MIT-NRAO Surveys: 1990 southern-hemisphere radio surveys
• NRAO VLA Sky Survey: 1990s microwave survey of 82% of the sky
• NRES: see Las Cumbres Observatory
• NRL (Naval Research Laboratory): US Navy scientific research arm
• NRL White-light Coronagraph: see OSO 7
• NRQZ: see Green Bank Observatory
  • dark sky: sky with limited light pollution
• NRT (Nançay Radio Telescope): large radio telescope in France
• NRT: see Liverpool Telescope
• NRT: see Roque de los Muchachos Observatory
• NS (neutron star): stellar remnant consisting entirely of solar masses of neutrons
• NS: see Lunar Prospector
• NS: see MESSENGER
• NS: see rare designator prefixes
• NS equations (Navier-Stokes equations): equations that describe fluid dynamics
• NS kick: see velocity kick
  • core collapse supernova: supernova resulting from the collapse of the core of a star
• NS merger (neutron star merger): two neutron stars meeting and forming one
  • standard siren: transient whose gravitational waves indicate a specific distance
• NSB: see binary neutron star
• NSBH merger (neutron-star black-hole merger): a neutron star falling into a black hole
• NSBM (NASA Standard Breakup Model): model maintained by NASA of how satellites fragment
• NSC (NOAO Source Catalog): catalog compiled from NOAO public data
• NSC: see stellar nucleus
• NSE (nuclear statistical equilibrium): equilibrium of nuclei emitting and absorbing particles
• NSF (National Science Foundation): US government organization funding scientific research
  • LIGO: pair of observatories to detect gravitational waves
  • MEarth Project: automated observatories monitoring nearby red dwarfs for transits
  • memorandum of understanding: agreement between NSF and other research entities
  • National Optical Astronomy Observatory: previous name of US optical astronomy organization
  • National Radio Astronomy Observatory: US radio astronomy organization
  • NOIRLab: US optical/infrared astronomy organization
  • NSF AST: US government astronomical research funding division
  • Research Experience for Undergraduates: NSF funding program
  • Two Micron All-sky Survey: near-infrared survey of both hemispheres
• NSF AST: US government astronomical research funding division
• NSF AST MSIP: see NSF AST
• NSF Astronomical Sciences Division (NSF AST): US government astronomical research funding division
• NSFCam2: see IRTF
• NSII (Narrabri Stellar Intensity Interferometer): 1960s optical interferometer for measuring stellar diameters
• NSNF (Nearby Supernova Factory): survey that scanned transient data for supernovae
• NSO (National Solar Observatory): US government sponsored solar observatory
  • Association of Universities for Research in Astronomy: collaboration of universities operating observatories
• NSSDC (NASA Space Science Data Coordinated Archive): NASA archive of flight information and astronomy findings
• NSSDCA (NASA Space Science Data Coordinated Archive): NASA archive of flight information and astronomy findings
• NST: see Big Bear Solar Observatory
• NSV (New Catalogue of Suspected Variable Stars): catalog from latter half of 20th century catalog
• NSV Release 2: see New Catalogue of Suspected Variable Stars
• NSVS: see ROTSE
• NT (non-thermal): regarding radiation other than black-body
• NTT (New Technology Telescope): 3.58-meter reflector telescope in Chile
  • European Southern Observatory: organization operating telescopes in the southern hemisphere
  • La Silla Observatory: Atacama-desert observatory run by ESO
  • PESSTO: NTT survey following up on transients
  • WINERED: near-infrared non-cryogenic spectrograph
• NTTS: see T-Tauri star
• NTTS: see rare designator prefixes
• nuclear
• carbon burning: fusion reaction starting with carbon
• CNO cycle: fusion reaction chain turning hydrogen and nitrogen into helium and nitrogen
• deuterium burning: any fusion reaction starting with deuterium
• electron capture: combination of an electron with a proton
• helium burning: fusion reaction starting with helium
• hydrogen burning: any fusion reaction starting with hydrogen
• lithium burning: any fusion reaction starting with lithium
• metastable: characteristic of an excited state that lasts longer than typical
• neon burning: fusion reaction starting with neon
• oxygen burning: fusion reaction starting with oxygen
• proton-proton chain: type of fusion reaction chain turning hydrogen into helium
• silicon burning: alpha process fusion starting at silicon
• triple alpha process: fusion reaction chain turning helium-4 into carbon
• nuclear binding energy: see binding energy
• nuclear cluster (stellar nucleus): group of many stars at the center of a galaxy
• nuclear drip line: see neutron drip
• nuclear energy generation rate: fusion power per unit mass
• nuclear fission: see fusion
• nuclear fusion (fusion): formation of an atomic nucleus nuclei from multiple smaller nuclei
• nuclear isomer: see nuclide
  • metastable: characteristic of an excited state that lasts longer than typical
• nuclear photodissociation
• photodissociation: chemical reaction in which photons break chemical bonds
• nuclear reaction: see nuclear energy generation rate
  • fusion: formation of an atomic nucleus nuclei from multiple smaller nuclei
• nuclear reaction rate: see nuclear energy generation rate
• nuclear species (nuclide): atomic nucleus associated with a specific isotope
• Nuclear Spectroscopic Telescope Array (NuSTAR): space telescope for high-energy X-rays
• nuclear star cluster (stellar nucleus): group of many stars at the center of a galaxy
• nuclear star cluster: see stellar nucleus
• nuclear statistical equilibrium: equilibrium of nuclei emitting and absorbing particles
• nuclear symmetry energy: see valley of beta stability
• nuclear timescale: see timescale
• nucleon: proton or neutron
  • dalton: mass unit used on atomic scale
  • element: class of atom based on its number of protons
  • fusion: formation of an atomic nucleus nuclei from multiple smaller nuclei
  • isotope: subclass of an element with a specific number of nucleons
  • standard model: model of elementary particles including quarks
• nucleon number (mass number): number of nucleons in an atomic nucleus
• nucleosynthesis: creation of atomic nuclei
  • alpha capture: combination of a nucleus and an incoming alpha particle
  • alpha element: element created by alpha capture
  • alpha process: synthesis of elements through alpha capture
  • beta decay: radioactivity such that an electron or positron is emitted
  • Big Bang nucleosynthesis: creation of atomic nuclei in the very early universe
  • carbon burning: fusion reaction starting with carbon
  • CNO cycle: fusion reaction chain turning hydrogen and nitrogen into helium and nitrogen
  • deuterium burning: any fusion reaction starting with deuterium
  • electron capture: combination of an electron with a proton
  • endothermic reaction: reaction that absorbs heat
  • fusion: formation of an atomic nucleus nuclei from multiple smaller nuclei
  • Gamow peak: relative speed most likely to cause atoms to fuse within a gas
  • helium burning: fusion reaction starting with helium
  • hydrogen burning: any fusion reaction starting with hydrogen
  • iron peak element: element near the iron peak
  • lithium burning: any fusion reaction starting with lithium
  • neon burning: fusion reaction starting with neon
  • neutron capture: combination of an atomic nucleus and a neutron
  • neutron drip: neutrons exiting from nuclei
  • neutronization: an electron and proton combining to form a neutron
  • neutrons from carbon-13: process by which neutrons are freed in the s process
  • nuclear statistical equilibrium: equilibrium of nuclei emitting and absorbing particles
  • nuclide: atomic nucleus associated with a specific isotope
  • oxygen burning: fusion reaction starting with oxygen
  • p-process: synthesis of elements through proton capture
  • photodisintegration: breakdown of a nucleus by a gamma ray
  • proton-proton chain: type of fusion reaction chain turning hydrogen into helium
  • r-process: synthesis of elements through neutron capture faster than beta decay
  • radioactive decay: changes in atomic nuclei that happen over time
  • rp-process: synthesis of elements through repeated proton capture
  • s-process: synthesis of elements through neutron capture and beta decay
  • silicon burning: alpha process fusion starting at silicon
  • triple alpha process: fusion reaction chain turning helium-4 into carbon
  • Urca process: neutrino-emitting process
  • valley of beta stability: set of isotopes not prone to beta decay
• nucleotides
• Lego principle: principle that life is associated with a skew in molecule abundances
• nucleus: see comet
• nucleus notation
• isotope: subclass of an element with a specific number of nucleons
• nuclide: atomic nucleus associated with a specific isotope
  • radioactive decay: changes in atomic nuclei that happen over time
• Nuffield Radio Astronomy Laboratory (Jodrell Bank Observatory): radio observatory in England
• null corrector: instrument for testing mirrors
• null hypothesis
• Bayesian statistics: statistics method assigning probability to your belief
• null test: see null corrector
• nulling: see speckle suppression
• number density: number of objects per volume
  • particle number: number of particles
• numbered object: see minor planet
• numbered object: see provisional designation
• numerical analysis: the study and use of numerical methods of solving equations
  • analytical methods: using solved equations rather than a lot of arithmetic
  • finite difference method: means of estimating calculus and differential equation solutions
  • numerical methods: using equations through repetitive arithmetic
• numerical integration: see Markov chain Monte Carlo
• numerical integration: see numerical methods
• numerical methods: using equations through repetitive arithmetic
  • numerical analysis: the study and use of numerical methods of solving equations
  • stencil: pattern of input to numerical solutions at a point
• numerical model: see numerical methods
• numerical relativity: solving GR-sensitive problems with numerical methods
• numerical weather prediction: Earth weather prediction by computer equation-solving and/or simulation
• numerical weather prediction model: see numerical weather prediction
• NumPy: Python library for numerical programming with arrays
• NumPy: see PyMC
• NuSTAR: space telescope for high-energy X-rays
  • StrayCats: survey of X-ray sources detectable in NuSTAR stray light
• NUT parameter: see Taub-NUT spacetime
• nutation: precession of a body's axis of rotation
  • Chandler wobble: shifting of the Earth's axis of rotation relative to the Earth itself
• NUTS: see PyMC
• NUV: see ultraviolet
  • ULTRASAT: future satellite to detect UV transients
• NVSS (NRAO VLA Sky Survey): 1990s microwave survey of 82% of the sky
• NWO (Nederlandse Organisatie voor Wetenschappelijk Onderzoek): Dutch research council
  • ASTRON: Netherlands radio astronomy research organization
  • Astronet: European astronomy consortium
• NWP (numerical weather prediction): Earth weather prediction by computer equation-solving and/or simulation
• NWP model: see numerical weather prediction
  • subgrid-scale physics: shortcuts handling physics on a smaller scale than a simulation's grid
• Nysa
• asteroid family: set of asteroids based on similar orbits
• NZO: see double star designation