Term Index (K)

 K2  KA  KB  KC  KD  KE  KF  KH  KI  KJ  KK  KL  KM  KN  KO  KP  KR  KS  KU  KV  KW  KY  KZ

• K (K band): atmospheric window centered around 2.2 microns, or 136 THz
• K (K-type star): spectral class of star a bit cooler than the Sun
• K (kelvin): unit of temperature scale starting at absolute zero
• K: see King Catalog
• K: see rare designator prefixes
  • Two Micron All-sky Survey: near-infrared survey of both hemispheres
• k (Boltzmann constant): relates particle energy and temperature
• k (permeability): ability of a material to allow fluids to pass through it
• k: see Love number
• K band: atmospheric window centered around 2.2 microns, or 136 THz
  • infrared: light with wavelength too long for our eyes to sense
  • J-region asymptotic giant branch: standard candle consisting of selected AGB stars
• K Belt (Kuiper Belt): further part of solar system beyond Neptune
• K Belt object: see Kuiper Belt
• K correction: correction to magnitude for redshift
• K dwarf: see K-type star
  • M dwarf: small, cool main-sequence star in stellar class M
  • red dwarf: small, cool main-sequence star
• K line
• calcium: element, Ca, atomic number 20
• K+A galaxy (post-starburst galaxy): galaxy indicating star formation some time back
• K-band Multi-object Spectrograph (KMOS): 2-micron spectrograph on ESO VLT
• K-capture (electron capture): combination of an electron with a proton
• K-class: see K-type star
• K-class star (K-type star): spectral class of star a bit cooler than the Sun
• K-Cor: see Coronal Solar Magnetism Observatory
• K-Cor: see Mauna Loa Solar Observatory
• K-line: iron X-ray line
• K-type star: spectral class of star a bit cooler than the Sun
• K/Th ratio (potassium/thorium ratio): indication of thermal history
• K2: second Kepler mission that worked around failed equipment
  • ExoFOP: site to facilitate exoplanet follow-up observation
  • K2-18b: super-Earth in a habitable zone
  • Kepler Telescope: space telescope that watched stars for exoplanets
• K2-18: see K2-18b
• K2-18b: super-Earth in a habitable zone
• k_B (Boltzmann constant): relates particle energy and temperature
• k_DM: see dispersion measure
• KAGRA: gravitational wave detector in Japan preparing for operation
• Kaguya (SELENE): 2007-2008 Japanese lunar probe
• Kaiser distortion: see redshift space
• KAIT: see Lick Observatory
  • Lick Observatory Supernova Search: search for supernovae for cosmological study
• Kaj Strand Telescope: see USNO
• Kamioka Gravitational Wave Detector (KAGRA): gravitational wave detector in Japan preparing for operation
• Kamioka Liquid Scintillator Antineutrino Detector: see Kamioka Observatory
• Kamioka Nucleon Decay Experiment: see Kamioka Observatory
• Kamioka Observatory: Japanese underground particle detector
• Kamiokande-II: see Kamioka Observatory
• KamiokeNDE: see Kamioka Observatory
• KamLAND: see Kamioka Observatory
• KAO (Kuiper Airborne Observatory): infrared observatory-plane in the 1980s
  • WINERED: near-infrared non-cryogenic spectrograph
• kappa distribution: one distribution of velocities of particles out of equilibrium
• kappa mechanism: stellar instability caused by opacity increasing with temperature
  • instability strip: region of H-R diagram where stars are unstable
• Kapteyn universe: early 20th century model of the universe centered on the Milky Way
• Kapteyn's Star: nearby M dwarf
• Karhula: see rare designator prefixes
• Karl G. Jansky Very Large Array (Very Large Array): radio telescope in New Mexico
• Karlsruhe Institute of Technology
• KATRIN: experiment to measure neutrino mass
• Karlsruhe Tritium Neutrino Experiment (KATRIN): experiment to measure neutrino mass
• Karoo Array Telescope (MeerKAT): new radio telescope in South Africa
• KASI
• East Asian Observatory: operator of JCMT
• Kast Spectrograph: see Shane Telescope
• KAT: see MeerKAT
• KAT-7
• MeerKAT: new radio telescope in South Africa
• Katalog von 1053 stärker bewegten Fixsternen (Max Wolf's catalog of stars with proper motion): early 20th century catalog of 1500 stars
• KATE: see SMART-1
• KATRIN: experiment to measure neutrino mass
• Katzman Automatic Imaging Telescope: see Lick Observatory
  • Lick Observatory Supernova Search: search for supernovae for cosmological study
• Kavli Foundation
• Kavli Institute: any of a number of science institutes supported by Kavli Foundation
• Kavli Institute: any of a number of science institutes supported by Kavli Foundation
• Kavli Institute for Astronomy and Astrophysics: see Kavli Institute
• Kavli Institute for Astrophysics and Space Research: see Kavli Institute
• Kavli Institute for Cosmological Physics: see Kavli Institute
• Kavli Institute for Cosmology: see Kavli Institute
• Kavli Institute for Particle Astrophysics and Cosmology: see Kavli Institute
• Kavli Institute for the Physics and Mathematics of the Universe: see Kavli Institute
• Kavli IPMU: see Kavli Institute
• Kazarian: see rare designator prefixes
• Kazochok: see ExoMars
• KB (Kuiper Belt): further part of solar system beyond Neptune
• KB object: see Kuiper Belt
• KBO: see Kuiper Belt
  • Haumea: dwarf planet discovered in 2004
  • New Horizons: explorer spaceship sent to Pluto
  • Pluto: dwarf planet formerly listed as one of the nine planets
  • plutoid: Pluto-like dwarf planet
  • Sedna: distant solar system planetoid discovered in 2003
• KBOs
• solar system object: the Sun, solar system planets, minor planets, comets, and moons
• KCAO (Kumamoto Civil Astronomical Observatory): Japanese amateur observatory
• KCRM: see Keck Observatory
• KCWI: see Keck Observatory
• KDG: see rare designator prefixes
• KE (kinetic energy): an object's energy due to its motion
• Keck (Keck Observatory): observatory in Hawaii with two 10-meter reflectors
  • TESS-Keck Survey: Keck follow-up survey to TESS discoveries
• Keck 1
• Gliese 436 b: hot Neptune found in 2004
• HD 80606 b: hot Jupiter discovered in 2001
• Keck Array: see BICEP2
  • South Pole Station: science station at the South Pole
• Keck I: see Keck Observatory
  • HD 209458 b: hot Jupiter discovered in 1999
• Keck II: see Keck Observatory
  • Keck Planet Imager and Characterizer: extreme AO upgrade under development for Keck
  • SPLASH: survey of M31's Giant Stellar Stream
• Keck Interferometer: see Keck Observatory
  • optical interferometer: interferometer of visible light
• Keck Observatory: observatory in Hawaii with two 10-meter reflectors
  • California-Kepler Survey: follow-up to Kepler to determine stellar radii
  • Keck Planet Finder: Keck I spectrograph for RV measurements
  • Keck Planet Imager and Characterizer: extreme AO upgrade under development for Keck
  • Mauna Kea: Hawaiian mountain, the site of observatories
  • Mauna Kea Observatories: observatories on Mauna Kea in Hawaii
  • PALMS: survey to find exoplanets for direct imaging
• Keck Planet Finder: Keck I spectrograph for RV measurements
• Keck Planet Imager and Characterizer: extreme AO upgrade under development for Keck
• Keck Planet Imager and Characterizer: see Keck Observatory
• KELT: pair of telescopes that searched for transients
• KELT-North: see KELT
• KELT-South: see KELT
• kelvin: unit of temperature scale starting at absolute zero
• Kelvin scale: see kelvin
  • Boltzmann constant: relates particle energy and temperature
• Kelvin time: see timescale
• Kelvin waves: pressure and gravity waves formed by Coriolis force and a barrier
• Kelvin-Helmholtz contraction: see Kelvin-Helmholtz mechanism
• Kelvin-Helmholtz instability: waves forming from velocity shear
• Kelvin-Helmholtz mechanism: release of energy from gravitational collapse
• Kelvin-Helmholtz time (Kelvin-Helmholtz timescale): time that would radiate away a body's heat energy given its luminosity
• Kelvin-Helmholtz timescale: time that would radiate away a body's heat energy given its luminosity
• Kelvin-Helmholtz timescale: see timescale
• Kennicutt-Schmidt law: relation between gas density and star formation rate
• Kennicutt-Schmidt relation (Kennicutt-Schmidt law): relation between gas density and star formation rate
• Kepler (Kepler Telescope): space telescope that watched stars for exoplanets
  • KIC 8462852: star with unusual variations
• Kepler dichotomy: see Kepler Telescope
• Kepler Field: see Kepler Telescope
  • Kepler-Swift Active Galaxies and Stars Survey: X-ray/UV survey of objects within the Kepler field
• Kepler Input Catalog: see Kepler Telescope
• Kepler object of interest: see Kepler Telescope
• Kepler orbit (Keplerian orbit): orbit following a perfect ellipse or other conic section
• Kepler Orrery I: see orrery
• Kepler radius: radius at which a particular velocity would orbit
• Kepler radius distribution
• Kepler radius: radius at which a particular velocity would orbit
• Kepler SNR: see Kepler's Supernova
• Kepler Telescope: space telescope that watched stars for exoplanets
  • combined differential photometric precision: calculated relation of photometric variation to SNR
  • ExoFOP: site to facilitate exoplanet follow-up observation
  • gaia-kepler.fun: website with Gaia data on Kepler target stars
  • Kepler-1625b: giant exoplanet in a star's habitable zone
  • Kepler-16b: exoplanet orbiting a binary star
  • Kepler-186f: Earth-like exoplanet in a star's habitable zone
  • Kepler-452b: Earth-like exoplanet discovered in 2015
• Kepler's laws: laws of the kinematics of orbits
  • celestial mechanics: study of forces and motion of celestial objects
• Kepler's laws of planetary motion (Kepler's laws): laws of the kinematics of orbits
• Kepler's Supernova: Type Ia supernova observed in 1604 by Johannes Kepler
• Kepler's supernova
• Cassiopeia A: supernova remnant visible for 300 years
• Kepler-16: see Kepler-16b
• Kepler-1625: see Kepler-1625b
• Kepler-1625b: giant exoplanet in a star's habitable zone
• Kepler-1625b-I: see Kepler-1625b
• Kepler-16b: exoplanet orbiting a binary star
  • circumbinary planet: exoplanet orbiting two stars
• Kepler-186: see Kepler-186f
• Kepler-186f: Earth-like exoplanet in a star's habitable zone
• Kepler-2b (HAT-P-7b): hot Jupiter discovered in 2008
• Kepler-452: see Kepler-452b
• Kepler-452b: Earth-like exoplanet discovered in 2015
• Kepler-79: star with four super-puff planets
• Kepler-79b: see Kepler-79
• Kepler-Swift Active Galaxies and Stars Survey: X-ray/UV survey of objects within the Kepler field
• Keplerian disk: disk whose motion follows Kepler's laws
• Keplerian orbit: orbit following a perfect ellipse or other conic section
  • Kepler's laws: laws of the kinematics of orbits
• Keplerian radius
• Kepler radius: radius at which a particular velocity would orbit
• Keplerian speed: see Keplerian orbit
• Kerberos: see Pluto
• Kerr BH (Kerr black hole): spinning black hole with no charge
• Kerr black hole: spinning black hole with no charge
• Kerr black hole: see black hole model
  • gravitational singularity: point where density and gravity reach infinity
• Kerr metric: see Kerr black hole
• Kerr object (Kerr black hole): spinning black hole with no charge
• Kerr object: see black hole model
• Kerr spacetime: see Kerr black hole
  • Kerr-NUT spacetime: Kerr spacetime defined in terms of Taub-NUT spacetime
• Kerr-Newman black hole: see black hole model
  • Kerr black hole: spinning black hole with no charge
• Kerr-Newman metric: see metric
• Kerr-Newman object: see black hole model
• Kerr-NUT spacetime: Kerr spacetime defined in terms of Taub-NUT spacetime
• Kerr-Taub-NUT spacetime (Kerr-NUT spacetime): Kerr spacetime defined in terms of Taub-NUT spacetime
• Kessler syndrome: low-Earth-orbit debris growing out of control
• Kesteven: see rare designator prefixes
• KFL: see rare designator prefixes
• KFPA: see Green Bank Telescope
• KH: see rare designator prefixes
• Kh: see rare designator prefixes
• KH instability (Kelvin-Helmholtz instability): waves forming from velocity shear
• KH mechanism (Kelvin-Helmholtz mechanism): release of energy from gravitational collapse
• KH time (Kelvin-Helmholtz timescale): time that would radiate away a body's heat energy given its luminosity
• KH timescale (Kelvin-Helmholtz timescale): time that would radiate away a body's heat energy given its luminosity
• KH timescale: see timescale
• Kharchenko: see rare designator prefixes
• KHG: see rare designator prefixes
• KHI (Kelvin-Helmholtz instability): waves forming from velocity shear
• KI: see Keck Observatory
  • optical interferometer: interferometer of visible light
• KIAA: see Kavli Institute
• Kibel number (Rossby number): ratio of inertial to Coriolis force
• KIC: see Kepler Telescope
• KIC 8462852: star with unusual variations
• KICC: see Kavli Institute
• kick (velocity kick): substantial acceleration from a supernova
• kick: see core collapse supernova
  • hypervelocity star: star moving very much faster than usual
• kicked: see free-floating planet
• kicked out: see gravitationally bound
• KID: type of sensitive electronic device to detect light
• KiDS
• VLT Survey Telescope: survey telescope located at the VLT site
• KIDs Interferometer Spectrum Survey: see CONCERTO
• KIG: see rare designator prefixes
• Kilo-degree Survey
• VLT Survey Telescope: survey telescope located at the VLT site
• kilocalorie: see energy
• Kilodegree Extremely Little Telescope (KELT): pair of telescopes that searched for transients
• kilometer size barrier: barrier to further growth of planetesimals on the order of a km diameter
  • barrier: challenging issue regarding planet formation
• kilonova: transient associated with merging neutron stars
  • neutron star merger: two neutron stars meeting and forming one
  • standard siren: transient whose gravitational waves indicate a specific distance
• kilonova light curve
• supernova light curve: changing intensity of light following a supernova
• kiloparsec: see parsec
• Kim 1
• Milky Way subgroup: the Milky Way and its satellites
• KIMS: see COSINE-100
• kinematic distance: distance to objects within Milky Way based on radial velocity
• kinematic distance ambiguity: see kinematic distance
• kinematic group (moving group): observed group of stars with similar motion
  • stellar cluster: group of stars apparently formed by a single cloud
• kinematic Sunyaev-Zel'dovich effect: see Sunyaev-Zel'dovich effect
• kinematics: see mechanics
  • age-velocity-dispersion relation: relation between stellar age and peculiar velocity
  • celestial mechanics: study of forces and motion of celestial objects
  • Chandler wobble: shifting of the Earth's axis of rotation relative to the Earth itself
  • ephemeris: information on the position of a celestial body in the sky over time
  • epicycle: small circular motion around a large circular motion
  • epicyclic frequency: frequency of oscillation in an accretion disk
  • gravitational potential: conceptual field indicating the strength of gravity at each point
  • gravitational potential well: a dip in the gravitational-potential field
  • Kepler's laws: laws of the kinematics of orbits
  • Laplace-Lagrange secular theory: theory of evolution of planetary orbits
  • libration: oscillating motion of orbiting bodies relative to each other
  • mean anomaly: angle describing an object's position within an elliptical orbit
  • nutation: precession of a body's axis of rotation
  • Oort constants: two constants characterizing local Milky-Way motion
  • orbital element: parameters describing an orbit
  • precession: periodic change in a body's rotation or orbit
  • precession of the equinoxes: Earth axial precession with a 26000-year cycle
  • rotation period: time it takes an astronomical body to revolve
  • secular: occurring slowly over a long period of time
  • stellar kinematics: science of the movement of stars
  • synchronous orbit: orbit with angular velocity matching the rotation of the orbited body
  • velocity-metallicity relation: higher stellar velocity correlates with lower metallicity
• kinemetry: method of determining galaxy kinematics through photometry
• kinetic energy: an object's energy due to its motion
• kinetic equilibrium: see local thermodynamic equilibrium
• kinetic inductance detector (KID): type of sensitive electronic device to detect light
• kinetic Reynolds number (Reynolds number): measure reflecting a fluid system's propensity to turbulence
• kinetic temperature: see temperature
• kinetic theory of gases
• cross section: "area" representation of probability of an interaction of particles
• heating: increasing the velocity of particles
• kinetic-limited weathering: see weathering
• kinetics
• normal mode: resonant surface waves in seismology
• King: see King Catalog
• King Catalog: list of 21 open clusters
• KIPAC: see Kavli Institute
• KIPC: see Kavli Institute
• Kirchhoff diffraction formula
• diffraction: an effect of the edge of an obstacle on a wave
• Kirchhoff's law of thermal radiation: for an object in thermodynamic equilibrium, emissivity equals absorptance
  • gray body: ideal object that reflects the same fraction of light at any wavelength
• Kirchhoff's Laws
• thermal emission: EMR due to a body's heat
• Kirchhoff's laws: laws regarding the source of spectral lines
• Kirchhoff's three laws of spectroscopy (Kirchhoff's laws): laws regarding the source of spectral lines
• Kirkwood gap: gaps in asteroid orbital radii corresponding to Jupiter resonances
• Kiso 105-cm Schmidt telescope
• Kiso Survey of Ultraviolet Excess Galaxies: 1980 Japanese survey
• Kiso Observatory
• Kiso Survey of Ultraviolet Excess Galaxies: 1980 Japanese survey
• Kiso Survey of Ultraviolet Excess Galaxies: 1980 Japanese survey
• KISS: see CONCERTO
• Kitt Peak 4m (Mayall 4m Telescope): 4 meter reflector telescope at Kitt Peak
  • National Optical Astronomy Observatory: previous name of US optical astronomy organization
• Kitt Peak National Observatory: NOIRLab observatory in Arizona with Mayall telescope
  • ARO 12m Telescope: twelve meter microwave telescope at KPNO
  • BigBOSS: BOSS survey follow-on
  • Cerro Tololo Inter-American Observatory: NOIRLab observatory in Chile with Blanco telescope
  • Dark Energy Spectroscopic Instrument: new instrument for measuring red-shift of distant objects
  • Deep Lens Survey: investigating mass distribution of the universe
  • Livermore Optical Transient Imaging System: automated telescope aiming to catch GRB optical counterparts
  • Mayall 4m Telescope: 4 meter reflector telescope at Kitt Peak
  • National Optical Astronomy Observatory: previous name of US optical astronomy organization
  • National Solar Observatory: US government sponsored solar observatory
  • NOAO Deep Wide-field Survey: survey investigating large scale structure of the universe
  • SKHB: survey of globular clusters in M31
  • SPACEWATCH: survey to study minor planets
  • Víctor M. Blanco Telescope: 4 meter reflector telescope in Chile
  • WIYN 3.5m Telescope: Kitt Peak telescope run by university collaboration and NOIRLab
• KjPn: see rare designator prefixes
• KK: see rare designator prefixes
• KKH: see rare designator prefixes
• KKR: see rare designator prefixes
• KKS: see rare designator prefixes
• Klein-Nishina formula: formula for the effects of electrons scattering photons
• Klemola: see rare designator prefixes
• kly: see light-year
• KM3NeT: neutrino detector under construction in the Mediterranean Sea
• KM3NeT-Fr: see KM3NeT
• KM3NeT-Gr: see KM3NeT
• KM3NeT-It: see KM3NeT
• KMOS: 2-micron spectrograph on ESO VLT
• KMOS: see European Southern Observatory Very Large Telescope
• KMOS3D: survey of galaxies before to after peak star formation
• KMS: see rare designator prefixes
• KMT: see Korea Microlensing Telescope Network
• KMTNet (Korea Microlensing Telescope Network): survey searching for microlensing transients
• KN (kilonova): transient associated with merging neutron stars
• Knee: see Swordy plot
• KNT: see double star designation
• KO: see double star designation
• KO: see rare designator prefixes
• KOALA: see Anglo-Australian Telescope
• koala: see AT2018cow
• KOI: see Kepler Telescope
  • ExoFOP: site to facilitate exoplanet follow-up observation
• KOI-152 (Kepler-79): star with four super-puff planets
• KOI-152.03: see Kepler-79
• KOI-1611: see Kepler-16b
• KOI-1611.02 (Kepler-16b): exoplanet orbiting a binary star
• KOI-5084: see Kepler-1625b
• KOI-5084.1 (Kepler-1625b): giant exoplanet in a star's habitable zone
• KOI-571: see Kepler-186f
• KOI-571.05 (Kepler-186f): Earth-like exoplanet in a star's habitable zone
• KOI-7016: see Kepler-452b
• KOI-7016.01 (Kepler-452b): Earth-like exoplanet discovered in 2015
• Kolmogorov energy spectrum (Kolmogorov spectrum): energy spectrum of the eddies of different sizes in a turbulent fluid
• Kolmogorov spectrum: energy spectrum of the eddies of different sizes in a turbulent fluid
• Kongjian Xinjishu Shiyan 01 (Satech-01): Chinese experimental spacecraft
• Konkoly Observatory
• HATNet: distributed array of telescopes to search for transients
• Konus
• Konus-Wind catalog: catalog of GRBs from the Wind spacecraft
• KONUS-B: see GRANAT
• Konus-Wind catalog: catalog of GRBs from the Wind spacecraft
• Koposov: see rare designator prefixes
• Koposov I: low-luminosity globular cluster in the constellation Virgo
• Koposov II: low-luminosity globular cluster in the constellation Gemini
• Korea
• Bohyunsan Optical Astronomy Observatory: on Bohyeon Mountain, Korea
• Korea Microlensing Telescope Network: survey searching for microlensing transients
• Korean
• Korea Microlensing Telescope Network: survey searching for microlensing transients
• Korean Astronomy and Space Science Institute
• East Asian Observatory: operator of JCMT
• Korean Invisible Mass Search: see COSINE-100
• Korean Solar Radio Burst Locator: see Owens Valley Radio Observatory
• Kormendy Relation: relation between elliptical galaxy luminosity surface brightness
• Koronis
• asteroid family: set of asteroids based on similar orbits
• Korsch telescope: type of three-mirror reflector telescope
• Kowal's Object (Sagittarius Dwarf Irregular Galaxy): most distant galaxy in the Local Group
• Koyama Astronomical Observatory
• WINERED: near-infrared non-cryogenic spectrograph
• Kozai cycle: see Kozai mechanism
• Kozai mechanism: an effect on an orbit by another, more distant orbiting body
• Kozai oscillation: see Kozai mechanism
• Kozai-Lidov oscillation: see Kozai mechanism
• KP: see rare designator prefixes
• kpc: see parsec
• KPD: see rare designator prefixes
• KPF (Keck Planet Finder): Keck I spectrograph for RV measurements
• KPG: see rare designator prefixes
• KPIC (Keck Planet Imager and Characterizer): extreme AO upgrade under development for Keck
• KPIC: see Keck Observatory
  • extreme adaptive optics: high-performance version of AO system
• KPNO (Kitt Peak National Observatory): NOIRLab observatory in Arizona with Mayall telescope
  • ARO 12m Telescope: twelve meter microwave telescope at KPNO
  • BigBOSS: BOSS survey follow-on
  • Cerro Tololo Inter-American Observatory: NOIRLab observatory in Chile with Blanco telescope
  • Dark Energy Spectroscopic Instrument: new instrument for measuring red-shift of distant objects
  • Deep Lens Survey: investigating mass distribution of the universe
  • Mayall 4m Telescope: 4 meter reflector telescope at Kitt Peak
  • National Optical Astronomy Observatory: previous name of US optical astronomy organization
  • National Solar Observatory: US government sponsored solar observatory
  • NOAO Deep Wide-field Survey: survey investigating large scale structure of the universe
  • SKHB: survey of globular clusters in M31
  • Víctor M. Blanco Telescope: 4 meter reflector telescope in Chile
  • WIYN 3.5m Telescope: Kitt Peak telescope run by university collaboration and NOIRLab
• KPNO 2.1 m Telescope: see Kitt Peak National Observatory
• KPNO 4m (Mayall 4m Telescope): 4 meter reflector telescope at Kitt Peak
  • Kitt Peak National Observatory: NOIRLab observatory in Arizona with Mayall telescope
  • Local Group Galaxy Survey: photometric survey of stars in a number of local group galaxies
  • National Optical Astronomy Observatory: previous name of US optical astronomy organization
• KPNO-Tau: see rare designator prefixes
• KR (Kormendy Relation): relation between elliptical galaxy luminosity surface brightness
• KR: see double star designation
• KR: see rare designator prefixes
• Kr: see rare designator prefixes
• Kramers opacity law: opacity's relation to density and temperature
• Kramers' law
• Kramers opacity law: opacity's relation to density and temperature
• Kron: see rare designator prefixes
• Kronberger: see rare designator prefixes
• Kroupa IMF: see initial mass function
• Krylov subspace
• Krylov subspace method: efficient method of numerically solving sets of linear equations
• Krylov subspace method: efficient method of numerically solving sets of linear equations
• KS: see Kvant 1
• KSRBL: see Owens Valley Radio Observatory
• KSwAGS (Kepler-Swift Active Galaxies and Stars Survey): X-ray/UV survey of objects within the Kepler field
• kSZ: see Sunyaev-Zel'dovich effect
• kSZE: see Sunyaev-Zel'dovich effect
• KU: see double star designation
• Ku: see rare designator prefixes
• KU-BAND: see Parkes Observatory
• Kueyen Telescope: see European Southern Observatory Very Large Telescope
• KUG (Kiso Survey of Ultraviolet Excess Galaxies): 1980 Japanese survey
• kugelblitz: theoretical black hole arising from a high radiation density
• KUI: see double star designation
• Kuiper Airborne Observatory: infrared observatory-plane in the 1980s
• Kuiper Belt: further part of solar system beyond Neptune
• Kuiper Belt object: see Kuiper Belt
  • plutoid: Pluto-like dwarf planet
• Kuiper belt object
• New Horizons: explorer spaceship sent to Pluto
• Kuiper Belt objects
• minor planet: lesser solar system body without comet characteristics
• solar system object: the Sun, solar system planets, minor planets, comets, and moons
• Kumamoto Civil Astronomical Observatory: Japanese amateur observatory
• kurtosis: measure of the probability of a distribution's tails
• KUV: see rare designator prefixes
• Kvant 1: scientific module on Mir space station
• KW: see rare designator prefixes
• Kyoto3DII: see Subaru Telescope
• KZP: see New Catalogue of Suspected Variable Stars