{"https://codexery.com/stars-and-stellar-objects/e/stars-and-stellar-objects/active-galactic-nucleus/": {"t": "Active galactic nucleus", "s": "Compact region at a galaxy's center emitting non-stellar radiation, powered by accretion onto a supermassive black hole."}, "https://codexery.com/novels-by-robert-a-heinlein/e/novels-by-robert-a-heinlein/variable-star/": {"t": "Variable Star", "s": "A young musician flees romance aboard a starship colony mission."}, "https://codexery.com/black-holes/e/black-holes/astrophysical-jet/": {"t": "Astrophysical jet", "s": "Bipolar streams of ionised matter expelled at high velocity."}, "https://codexery.com/astronomical-radio-sources/e/astronomical-radio-sources/radio-galaxy/": {"t": "Radio galaxy", "s": "Galaxies with giant radio lobes powered by jets from active nuclei."}, "https://codexery.com/astronomy/e/astronomy/elliptical-galaxy/": {"t": "Elliptical galaxy", "s": "Elliptical galaxies are smooth, ellipsoidal galaxies with old stars."}, "https://codexery.com/stars-of-cancer/e/stars-of-cancer/oj-287/": {"t": "OJ 287", "s": "A supermassive black hole binary with 12-year optical outbursts."}, "https://codexery.com/stars-of-hercules/e/stars-of-hercules/markarian-501/": {"t": "Markarian 501", "s": "A blazar galaxy with extreme gamma-ray flares and a relativistic jet."}, "https://codexery.com/astrophotography/e/astrophotography/charge-coupled-device/": {"t": "Charge-coupled device", "s": "An integrated circuit that converts light into electric charge for imaging."}, "https://codexery.com/space-missions/e/space-missions/the-hubble-space-telescope/": {"t": "The Hubble Space Telescope", "s": "A versatile space telescope observing ultraviolet, visible, and near-infrared light."}, "https://codexery.com/cosmology-concepts/e/cosmology-concepts/redshift/": {"t": "Redshift", "s": "Redshift measures the stretching of light from moving or distant sources."}, "https://codexery.com/electromagnetism-and-waves/e/electromagnetism-and-waves/polarization-waves/": {"t": "Polarization (waves)", "s": "Property of transverse waves specifying oscillation orientation."}, "https://codexery.com/galaxy-clusters-and-groups/e/galaxy-clusters-and-groups/galaxy-cluster/": {"t": "Galaxy cluster", "s": "Largest gravitationally bound structures, composed of galaxies, gas, and dark matter."}, "https://codexery.com/astronomy/e/astronomy/galaxy-morphological-classification/": {"t": "Galaxy morphological classification", "s": "A system for classifying galaxies by visual appearance and structure."}, "/e/galaxies-and-their-properties/type-cd-galaxy/": {"t": "Type-cD galaxy", "s": "Supergiant elliptical galaxies at the centres of rich clusters."}, "https://codexery.com/cosmic-mysteries/e/cosmic-mysteries/dark-matter/": {"t": "Dark matter", "s": "Invisible matter inferred from gravitational effects on cosmic scales."}, "https://codexery.com/nebulae/e/nebulae/interstellar-cloud/": {"t": "Interstellar cloud", "s": "Denser-than-average regions of the interstellar medium, where hydrogen can be neutral, ionized, or molecular."}, "/e/galaxies-and-their-properties/galactic-tide/": {"t": "Galactic tide", "s": "Tidal force from a galaxy's gravitational field."}, "https://codexery.com/galaxy-clusters-and-groups/e/galaxy-clusters-and-groups/dragonfly-44/": {"t": "Dragonfly 44", "s": "Ultra diffuse galaxy with disputed dark matter content."}, "https://codexery.com/classical-mechanics/e/classical-mechanics/mass/": {"t": "Mass", "s": "Intrinsic property measuring inertia and gravitational attraction."}, "https://codexery.com/spiral-galaxies/e/spiral-galaxies/milky-way/": {"t": "Milky Way", "s": "The barred spiral galaxy containing the Solar System."}, "https://codexery.com/science-measurement/e/science-and-measurement/radio-telescope/": {"t": "Radio telescope", "s": "Detecting the invisible universe through radio waves.", "i": "https://codexery.com/science-measurement/img/science-and-measurement/radio-telescope.webp", "c": "Photograph by Mike Peel ( www.mikepeel.net ). · CC BY-SA 4.0"}, "https://codexery.com/radio-telescopes/e/radio-telescopes/arecibo-observatory/": {"t": "Arecibo Observatory", "s": "Former world's largest single-aperture radio telescope, collapsed in 2020."}, "https://codexery.com/radio-telescopes/e/radio-telescopes/parkes-observatory/": {"t": "Parkes Observatory", "s": "Home of Murriyang, the 64 m dish that relayed Apollo 11 TV."}, "https://codexery.com/separation-and-purification-techniques/e/separation-and-purification-techniques/spectroscopy/": {"t": "Spectroscopy", "s": "Spectroscopy measures and interprets electromagnetic spectra interacting with matter."}, "https://codexery.com/messier-objects/e/messier-objects/messier-99/": {"t": "Messier 99", "s": "A grand design spiral galaxy with a distorted arm and a hydrogen bridge."}, "https://codexery.com/constellations/e/constellations/andromeda/": {"t": "Andromeda", "s": "Andromeda: a princess, a constellation, and a galaxy."}, "https://codexery.com/cosmology-concepts/e/cosmology-concepts/physical-cosmology/": {"t": "Physical cosmology", "s": "Study of the universe's origin, structure, and evolution."}, "https://codexery.com/astronomy-space/e/astronomy-and-space/observable-universe/": {"t": "Observable universe", "s": "The portion of the universe visible from Earth."}, "https://codexery.com/cosmology-concepts/e/cosmology-concepts/expansion-of-the-universe/": {"t": "Expansion of the universe", "s": "The increase in distance between gravitationally unbound parts of the universe."}, "https://codexery.com/cosmology-concepts/e/cosmology-concepts/lambda-cdm-model/": {"t": "Lambda-CDM model", "s": "Standard cosmological model of dark energy and cold dark matter."}, "https://codexery.com/galaxies/e/galaxies/galactic-disc/": {"t": "Galactic disc", "s": "A thin, rotating component of disc galaxies containing stars and gas."}, "https://codexery.com/astronomy/e/astronomy/galaxy-formation-and-evolution/": {"t": "Galaxy formation and evolution", "s": "Study of galaxy origins, structure, and change over cosmic time."}, "https://codexery.com/classical-mechanics/e/classical-mechanics/gravity/": {"t": "Gravity", "s": "Gravity is the fundamental attraction between objects with mass.", "i": "https://codexery.com/classical-mechanics/img/classical-mechanics/gravity.webp", "c": "https://commons.wikimedia.org/wiki/User:Nicoguaro · CC BY-SA 3.0"}, "https://codexery.com/astrophotography/e/astrophotography/radio-astronomy/": {"t": "Radio astronomy", "s": "Passive observation of celestial objects using radio waves.", "i": "https://codexery.com/astrophotography/img/astrophotography/radio-astronomy.webp", "c": "Maksym Kozlenko · CC BY-SA 4.0"}, "https://codexery.com/planets-stellar-astronomy/e/planets-and-stellar-astronomy/parsec/": {"t": "Parsec", "s": "Unit of distance defined by one arcsecond of parallax.", "i": "https://codexery.com/planets-stellar-astronomy/img/planets-and-stellar-astronomy/parsec.webp", "c": "via Wikipedia: Parsec · see source"}, "https://codexery.com/galaxy-clusters-and-groups/e/galaxy-clusters-and-groups/galaxy-group/": {"t": "Galaxy group", "s": "The smallest and most common galaxy aggregates in the universe."}, "https://codexery.com/messier-objects/e/messier-objects/messier-32/": {"t": "Messier 32", "s": "Prototype compact elliptical satellite of the Andromeda Galaxy."}, "https://codexery.com/messier-objects/e/messier-objects/andromeda-galaxy/": {"t": "Andromeda Galaxy", "s": "Nearest major galaxy to the Milky Way."}, "https://codexery.com/discoverers-of-astronomical-objects/e/discoverers-of-astronomical-objects/walter-baade/": {"t": "Walter Baade", "s": "German astronomer who doubled the known size of the universe."}, "https://codexery.com/ngc-objects/e/ngc-objects/ngc-147/": {"t": "NGC 147", "s": "A faint dwarf spheroidal satellite of the Andromeda Galaxy.", "i": "https://codexery.com/ngc-objects/img/ngc-objects/ngc-147.webp", "c": "Meli thev · CC BY-SA 4.0"}, "https://codexery.com/elliptical-and-irregular-galaxies/e/elliptical-and-irregular-galaxies/ngc-185/": {"t": "NGC 185", "s": "A dwarf spheroidal satellite of Andromeda with a disputed Seyfert nucleus."}, "https://codexery.com/astronomy-space/e/astronomy-and-space/local-group/": {"t": "Local Group", "s": "Galaxy group containing the Milky Way and Andromeda."}, "https://codexery.com/galaxy-clusters-and-groups/e/galaxy-clusters-and-groups/fornax-cluster/": {"t": "Fornax Cluster", "s": "Second richest galaxy cluster within 100 million light-years after Virgo."}, "https://codexery.com/spiral-galaxies/e/spiral-galaxies/spiral-galaxy/": {"t": "Spiral galaxy", "s": "Spiral galaxies feature rotating disks, arms, and often a central bar."}, "/e/galaxies-and-their-properties/interacting-galaxy/": {"t": "Interacting galaxy", "s": "Galaxies whose gravity disturbs one another.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/interacting-galaxy.webp", "c": "NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Eva · Public domain"}, "https://codexery.com/astronomy/e/astronomy/galaxy-groups-and-clusters/": {"t": "Galaxy groups and clusters", "s": "Largest gravitationally bound objects in cosmic structure formation."}, "/e/galaxies-and-their-properties/low-surface-brightness-galaxy/": {"t": "Low surface brightness galaxy", "s": "Diffuse galaxies dominated by dark matter, with faint stellar disks.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/low-surface-brightness-galaxy.webp", "c": "ESA/Hubble & NASA, C. Kilpatrick · CC BY 4.0"}, "/e/galaxies-and-their-properties/hubble-sequence/": {"t": "Hubble sequence", "s": "A morphological galaxy classification scheme published by Edwin Hubble in 1926.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/hubble-sequence.webp", "c": "Cosmogoblin · via Wikipedia: Hubble sequence · CC0"}, "https://codexery.com/galaxies/e/galaxies/local-volume/": {"t": "Local Volume", "s": "A spherical region of over 1,500 galaxies centered on the Local Group."}, "/e/galaxies-and-their-properties/dark-matter-halo/": {"t": "Dark matter halo", "s": "Invisible mass scaffold that shapes and binds every galaxy.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/dark-matter-halo.webp", "c": "ESO/L. Calçada · CC BY 4.0"}, "https://codexery.com/globular-clusters/e/globular-clusters/globular-cluster/": {"t": "Globular cluster", "s": "Spheroidal star clusters bound by gravity, found in galactic halos."}, "https://codexery.com/nebulae/e/nebulae/h-i-region/": {"t": "H I region", "s": "Neutral hydrogen clouds observed via 21-cm radio emission."}, "https://codexery.com/separation-and-purification-techniques/e/separation-and-purification-techniques/x-ray-spectroscopy/": {"t": "X-ray spectroscopy", "s": "Techniques for material analysis using X-ray radiation."}, "https://codexery.com/classical-mechanics-and-dynamics/e/classical-mechanics-and-dynamics/newton-s-laws-of-motion/": {"t": "Newton's laws of motion", "s": "Three laws describing motion and force relationships."}, "https://codexery.com/orbits-and-celestial-mechanics/e/orbits-and-celestial-mechanics/escape-velocity/": {"t": "Escape velocity", "s": "Minimum speed to escape a body's gravitational pull.", "i": "https://codexery.com/orbits-and-celestial-mechanics/img/orbits-and-celestial-mechanics/escape-velocity.webp", "c": "Richard West · CC BY-SA 2.0"}, "https://codexery.com/hypothetical-astronomical-objects/e/hypothetical-astronomical-objects/gaia-sausage/": {"t": "Gaia Sausage", "s": "Remains of a dwarf galaxy that merged with the Milky Way."}, "https://codexery.com/classical-and-continuum-mechanics/e/classical-and-continuum-mechanics/tidal-force/": {"t": "Tidal force", "s": "Differential gravity stretches bodies and drives tides across the cosmos."}, "https://codexery.com/relativity-and-gravitation/e/relativity-and-gravitation/gravitational-field/": {"t": "Gravitational field", "s": "A vector field explaining gravitational influences around a body.", "i": "https://codexery.com/relativity-and-gravitation/img/relativity-and-gravitation/gravitational-field.webp", "c": "MikeRun · CC BY-SA 4.0"}, "/e/galaxies-and-their-properties/satellite-galaxy/": {"t": "Satellite galaxy", "s": "Smaller galaxies bound to larger hosts, key to cosmology.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/satellite-galaxy.webp", "c": "Original:  AndrewRT Vector:  Slashme · via Wikipedia: Satellite galaxy · CC BY-SA 2.5"}, "https://codexery.com/astronomy-space/e/astronomy-and-space/oort-cloud/": {"t": "Oort cloud", "s": "Theorized reservoir of icy bodies at the Solar System's edge."}, "https://codexery.com/planets-stellar-astronomy/e/planets-and-stellar-astronomy/solar-system/": {"t": "Solar System", "s": "The Sun and all objects gravitationally bound to it.", "i": "https://codexery.com/planets-stellar-astronomy/img/planets-and-stellar-astronomy/solar-system.webp", "c": "via Wikipedia: Solar System · see source"}, "https://codexery.com/astronomy-space/e/astronomy-and-space/luminosity/": {"t": "Luminosity", "s": "Absolute measure of radiated electromagnetic energy per unit time."}, "https://codexery.com/astronomy-space/e/astronomy-and-space/molecular-cloud/": {"t": "Molecular cloud", "s": "Dense interstellar clouds where stars are born."}, "https://codexery.com/planets-stellar-astronomy/e/planets-and-stellar-astronomy/star-formation/": {"t": "Star formation", "s": "Process by which dense molecular cloud regions collapse into stars."}, "https://codexery.com/messier-objects/e/messier-objects/whirlpool-galaxy/": {"t": "Whirlpool Galaxy", "s": "First galaxy classified as spiral, interacting with NGC 5195."}, "https://codexery.com/messier-objects/e/messier-objects/messier-74/": {"t": "Messier 74", "s": "A grand design spiral galaxy with two clear arms."}, "https://codexery.com/messier-objects/e/messier-objects/messier-81/": {"t": "Messier 81", "s": "Grand design spiral galaxy with an active nucleus."}, "https://codexery.com/messier-objects/e/messier-objects/messier-83/": {"t": "Messier 83", "s": "A bright barred spiral galaxy near Earth.", "i": "https://codexery.com/messier-objects/img/messier-objects/messier-83.webp", "c": "ESO · CC BY 4.0"}, "https://codexery.com/messier-objects/e/messier-objects/pinwheel-galaxy/": {"t": "Pinwheel Galaxy", "s": "A large face-on spiral galaxy in Ursa Major."}, "https://codexery.com/caldwell-objects/e/caldwell-objects/ngc-6946/": {"t": "NGC 6946", "s": "A starburst galaxy with ten observed supernovae since 1917."}, "https://codexery.com/caldwell-objects/e/caldwell-objects/ic-342/": {"t": "IC 342", "s": "A bright spiral galaxy hidden behind Milky Way dust."}, "https://codexery.com/scientists-and-mathematicians/e/scientists-and-mathematicians/edwin-hubble/": {"t": "Edwin Hubble", "s": "The astronomer who revealed the universe beyond the Milky Way"}, "https://codexery.com/astronomy-space/e/astronomy-and-space/lenticular-galaxy/": {"t": "Lenticular galaxy", "s": "Intermediate galaxy type with disk and bulge, lacking spiral arms."}, "https://codexery.com/astronomy-space/e/astronomy-and-space/irregular-galaxy/": {"t": "Irregular galaxy", "s": "Galaxies without a distinct regular shape, often chaotic in appearance."}, "https://codexery.com/amateur-astronomy/e/amateur-astronomy/amateur-astronomy/": {"t": "Amateur astronomy", "s": "Amateur astronomers observe celestial objects for passion, education, and citizen science."}, "https://codexery.com/elliptical-and-irregular-galaxies/e/elliptical-and-irregular-galaxies/messier-49/": {"t": "Messier 49", "s": "First discovered Virgo Cluster member, a giant elliptical galaxy."}, "https://codexery.com/elliptical-and-irregular-galaxies/e/elliptical-and-irregular-galaxies/messier-59/": {"t": "Messier 59", "s": "Elliptical galaxy in Virgo with a counter-rotating supermassive black hole."}, "https://codexery.com/elliptical-and-irregular-galaxies/e/elliptical-and-irregular-galaxies/messier-60/": {"t": "Messier 60", "s": "Giant elliptical galaxy with a massive black hole in Virgo."}, "https://codexery.com/astronomy-space/e/astronomy-and-space/messier-87/": {"t": "Messier 87", "s": "A supergiant elliptical galaxy with a relativistic jet and supermassive black hole."}, "https://codexery.com/crystallography/e/crystallography/absorption-electromagnetic-radiation/": {"t": "Absorption (electromagnetic radiation)", "s": "Matter takes up photon energy, transforming it into internal energy.", "i": "https://codexery.com/crystallography/img/crystallography/absorption-electromagnetic-radiation.webp", "c": "Own work · CC0"}, "https://codexery.com/astronomers-and-cosmologists/e/astronomers-and-cosmologists/allan-sandage/": {"t": "Allan Sandage", "s": "American astronomer who determined the first accurate Hubble constant and age of the universe.", "i": "https://codexery.com/astronomers-and-cosmologists/img/astronomers-and-cosmologists/allan-sandage.webp", "c": "via Wikipedia: Allan Sandage · see source"}, "https://codexery.com/messier-objects/e/messier-objects/messier-86/": {"t": "Messier 86", "s": "Elliptical or lenticular galaxy with highest Messier blue shift.", "i": "https://codexery.com/messier-objects/img/messier-objects/messier-86.webp", "c": "Sloan Digital Sky Survey · CC BY 4.0"}, "https://codexery.com/elliptical-and-irregular-galaxies/e/elliptical-and-irregular-galaxies/ngc-1316/": {"t": "NGC 1316", "s": "Lenticular radio galaxy in the Fornax Cluster."}, "/e/galaxies-and-their-properties/dwarf-elliptical-galaxy/": {"t": "Dwarf elliptical galaxy", "s": "Small elliptical galaxies common in groups and clusters.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/dwarf-elliptical-galaxy.webp", "c": "NASA Hubble · CC BY 2.0"}, "https://codexery.com/black-holes/e/black-holes/black-hole/": {"t": "Black hole", "s": "An astronomical body from which nothing, not even light, can escape.", "i": "https://codexery.com/black-holes/img/black-holes/black-hole.webp", "c": "Event Horizon Telescope, uploader cropped and converted TIF to JPG · via Wikipedia: Black hole · CC BY 4.0"}, "https://codexery.com/elliptical-and-irregular-galaxies/e/elliptical-and-irregular-galaxies/sagittarius-dwarf-spheroidal-galaxy/": {"t": "Sagittarius Dwarf Spheroidal Galaxy", "s": "A looping dwarf galaxy being absorbed by the Milky Way."}, "https://codexery.com/classical-mechanics/e/classical-mechanics/momentum/": {"t": "Momentum", "s": "Vector quantity equal to mass times velocity."}, "https://codexery.com/observatories-of-europe/e/observatories-of-europe/paris-observatory/": {"t": "Paris Observatory", "s": "World's oldest active observatory, cornerstone of French astronomy."}, "https://codexery.com/galaxy-clusters-and-groups/e/galaxy-clusters-and-groups/coma-cluster/": {"t": "Coma Cluster", "s": "A rich galaxy cluster with over 1,000 members and abundant dark matter."}, "https://codexery.com/computing-digital/e/computing-and-digital/computer-simulation/": {"t": "Computer simulation", "s": "Running mathematical models on computers to represent real-world systems."}, "https://codexery.com/spiral-galaxies/e/spiral-galaxies/barred-spiral-galaxy/": {"t": "Barred spiral galaxy", "s": "A spiral galaxy with a central bar of stars."}, "https://codexery.com/elliptical-and-irregular-galaxies/e/elliptical-and-irregular-galaxies/dwarf-spheroidal-galaxy/": {"t": "Dwarf spheroidal galaxy", "s": "Small, dark-matter-dominated galaxies with old stars and little gas.", "i": "https://codexery.com/elliptical-and-irregular-galaxies/img/elliptical-and-irregular-galaxies/dwarf-spheroidal-galaxy.webp", "c": "Science NASA, ESA, Eduardo Vitral (STScI), Roeland van der Marel (STScI), Sangmo · Public domain"}, "https://codexery.com/binary-and-multiple-stars/e/binary-and-multiple-stars/accretion-disk/": {"t": "Accretion disk", "s": "Accretion disks are ubiquitous structures that drive mass onto central objects."}, "https://codexery.com/astronomical-concepts-and-techniques/e/astronomical-concepts-and-techniques/surface-brightness/": {"t": "Surface brightness", "s": "Surface brightness measures extended object visibility per angular area."}, "https://codexery.com/planets-and-dwarf-planets/e/planets-and-dwarf-planets/earth/": {"t": "Earth", "s": "The only known planet with liquid surface water and life."}, "https://codexery.com/astronomy/e/astronomy/dwarf-galaxy/": {"t": "Dwarf galaxy", "s": "Small galaxies shaped by larger neighbors and dark matter.", "i": "https://codexery.com/astronomy/img/astronomy/dwarf-galaxy.webp", "c": "ESA/Hubble & NASA · CC BY 4.0"}, "/e/galaxies-and-their-properties/field-galaxy/": {"t": "Field galaxy", "s": "A galaxy gravitationally alone, not in a group or cluster.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/field-galaxy.webp", "c": "NASA, ESA, and J. Lotz, M. Mountain, A. Koekemoer · CC BY 4.0"}, "https://codexery.com/spiral-galaxies/e/spiral-galaxies/malin-1/": {"t": "Malin 1", "s": "First verified low surface brightness galaxy and one of the largest spirals."}, "https://codexery.com/named-stars/e/named-stars/sun/": {"t": "Sun", "s": "The Sun is the central star of the Solar System."}, "https://codexery.com/asteroid-surveys/e/asteroid-surveys/iras/": {"t": "IRAS", "s": "First space telescope to survey the entire infrared sky."}, "https://codexery.com/electromagnetism-and-radiation/e/electromagnetism-and-radiation/visible-spectrum/": {"t": "Visible spectrum", "s": "The range of electromagnetic radiation visible to the human eye."}, "https://codexery.com/astronomy-space/e/astronomy-and-space/interstellar-medium/": {"t": "Interstellar medium", "s": "Matter and radiation between star systems in a galaxy."}, "https://codexery.com/nasa-space-probes/e/nasa-space-probes/wide-field-infrared-survey-explorer/": {"t": "Wide-field Infrared Survey Explorer", "s": "NASA infrared survey that mapped the entire sky."}, "https://codexery.com/lunar-gods/e/lunar-gods/chandra/": {"t": "Chandra", "s": "Hindu lunar deity and one of the nine planets."}, "https://codexery.com/elliptical-and-irregular-galaxies/e/elliptical-and-irregular-galaxies/large-magellanic-cloud/": {"t": "Large Magellanic Cloud", "s": "A dwarf satellite galaxy of the Milky Way, rich in gas and star formation."}, "https://codexery.com/astronomy-space/e/astronomy-and-space/main-sequence/": {"t": "Main sequence", "s": "Stars spend most of their lives on the main sequence."}, "https://codexery.com/stellar-phenomena/e/stellar-phenomena/supergiant/": {"t": "Supergiant", "s": "Massive, luminous stars at the top of the Hertzsprung–Russell diagram."}, "/e/galaxies-and-their-properties/unbarred-spiral-galaxy/": {"t": "Unbarred spiral galaxy", "s": "A spiral galaxy without a central bar structure."}, "/e/galaxies-and-their-properties/ring-galaxy/": {"t": "Ring galaxy", "s": "A galaxy with a ring-shaped structure of stars and gas."}, "https://codexery.com/black-holes/e/black-holes/supermassive-black-hole/": {"t": "Supermassive black hole", "s": "Supermassive black holes anchor the centers of most large galaxies.", "i": "https://codexery.com/black-holes/img/black-holes/supermassive-black-hole.webp", "c": "Event Horizon Telescope · via Wikipedia: Supermassive black hole · CC BY 4.0"}, "https://codexery.com/classical-mechanics/e/classical-mechanics/wave/": {"t": "Wave", "s": "A propagating disturbance that transfers energy and information."}, "https://codexery.com/elliptical-and-lenticular-galaxies/e/elliptical-and-lenticular-galaxies/cartwheel-galaxy/": {"t": "Cartwheel Galaxy", "s": "A lenticular ring galaxy shaped by a bullseye collision."}, "https://codexery.com/astronomical-x-ray-sources/e/astronomical-x-ray-sources/arp-147/": {"t": "Arp 147", "s": "Interacting ring galaxies formed by a disk-disk collision.", "i": "https://codexery.com/astronomical-x-ray-sources/img/astronomical-x-ray-sources/arp-147.webp", "c": "X-ray: NASA/CXC/MIT/S.Rappaport et al, Optical: NASA/STScI · Public domain"}, "https://codexery.com/galaxy-filaments/e/galaxy-filaments/galaxy-filament/": {"t": "Galaxy filament", "s": "Galaxy filaments are the largest known structures in the universe."}, "https://codexery.com/relativity-and-gravitation/e/relativity-and-gravitation/gravitational-potential/": {"t": "Gravitational potential", "s": "Scalar potential representing work per unit mass in a gravitational field.", "i": "https://codexery.com/relativity-and-gravitation/img/relativity-and-gravitation/gravitational-potential.webp", "c": "MikeRun · CC BY-SA 4.0"}, "https://codexery.com/stars-and-stellar-objects/e/stars-and-stellar-objects/cepheid-variable/": {"t": "Cepheid variable", "s": "Pulsating stars used as cosmic distance markers."}, "https://codexery.com/astronomical-surveys/e/astronomical-surveys/dark-energy-survey/": {"t": "Dark Energy Survey", "s": "A survey constraining dark energy through multiple cosmological probes."}, "/e/galaxies-and-their-properties/galactic-halo/": {"t": "Galactic halo", "s": "Extended spherical component of a galaxy beyond its visible parts.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/galactic-halo.webp", "c": "ESO · CC BY 4.0"}, "/e/galaxies-and-their-properties/brightest-cluster-galaxy/": {"t": "Brightest cluster galaxy", "s": "The most massive galaxies, found at cluster centers.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/brightest-cluster-galaxy.webp", "c": "ESO/J. Emerson/VISTA. Acknowledgment: Cambridge Astronomical Survey Unit · CC BY 4.0"}, "https://codexery.com/cosmology-concepts/e/cosmology-concepts/chronology-of-the-universe/": {"t": "Chronology of the universe", "s": "Standard timeline of cosmic history from inflation to present."}, "https://codexery.com/materials-and-states-of-matter/e/materials-and-states-of-matter/gas/": {"t": "Gas", "s": "A compressible fluid state of matter."}, "https://codexery.com/galaxy-clusters-and-groups/e/galaxy-clusters-and-groups/intracluster-medium/": {"t": "Intracluster medium", "s": "Superheated plasma permeating galaxy clusters, emitting strong X-rays."}, "https://codexery.com/classical-mechanics-and-dynamics/e/classical-mechanics-and-dynamics/kinetic-energy/": {"t": "Kinetic energy", "s": "Energy of motion, quantified as ½mv² in classical mechanics."}, "https://codexery.com/messier-objects/e/messier-objects/triangulum-galaxy/": {"t": "Triangulum Galaxy", "s": "A spiral galaxy and third-largest member of the Local Group."}, "/e/galaxies-and-their-properties/magellanic-spiral/": {"t": "Magellanic spiral", "s": "Dwarf spiral galaxies with a single prominent arm, often complex.", "i": "https://codexery.com/galaxies-and-their-properties/img/galaxies-and-their-properties/magellanic-spiral.webp", "c": "European Space Agency · via Wikipedia: Magellanic spiral · CC BY-SA 3.0 igo"}}