[{"n": "Planetary nebula", "u": "/e/planetary-nebulae/planetary-nebula/", "s": "Expanding shells of ionized gas from dying intermediate-mass stars."}, {"n": "Cat's Eye Nebula", "u": "/e/planetary-nebulae/cat-s-eye-nebula/", "s": "First planetary nebula shown to be gaseous via spectroscopy."}, {"n": "Cometary knot", "u": "/e/planetary-nebulae/cometary-knot/", "s": "Ionized photoevaporation flows in nearby planetary nebulae."}, {"n": "DdDm 1", "u": "/e/planetary-nebulae/dddm-1/", "s": "The only known oxygen-rich halo planetary nebula."}, {"n": "Dumbbell Nebula", "u": "/e/planetary-nebulae/dumbbell-nebula/", "s": "First discovered planetary nebula, in Vulpecula, visible in binoculars."}, {"n": "Engraved Hourglass Nebula", "u": "/e/planetary-nebulae/engraved-hourglass-nebula/", "s": "A young planetary nebula with an hourglass shape in Musca."}, {"n": "Eskimo Nebula", "u": "/e/planetary-nebulae/eskimo-nebula/", "s": "A bipolar double-shell planetary nebula in Gemini."}, {"n": "ETHOS 1", "u": "/e/planetary-nebulae/ethos-1/", "s": "A high-latitude planetary nebula with fast polar jets and a massive central star."}, {"n": "Exposed Cranium nebula", "u": "/e/planetary-nebulae/exposed-cranium-nebula/", "s": "A brain-like nebula with a dark vertical lane."}, {"n": "Fleming 1", "u": "/e/planetary-nebulae/fleming-1/", "s": "A planetary nebula with a binary white dwarf core."}, {"n": "Helix Nebula", "u": "/e/planetary-nebulae/helix-nebula/", "s": "A nearby planetary nebula with cometary knots and a helix shape."}, {"n": "HuBi 1", "u": "/e/planetary-nebulae/hubi-1/", "s": "A rare born-again planetary nebula with a fading central star."}, {"n": "Humason 1-2", "u": "/e/planetary-nebulae/humason-1-2/", "s": "Bipolar hourglass nebula with high-velocity knots and uncertain distance."}, {"n": "Humason 2-1", "u": "/e/planetary-nebulae/humason-2-1/", "s": "Bipolar planetary nebula discovered by Milton Lassel Humason in 1992."}, {"n": "IC 418", "u": "/e/planetary-nebulae/ic-418/", "s": "A bright planetary nebula with a spirograph-like pattern."}, {"n": "IC 1266", "u": "/e/planetary-nebulae/ic-1266/", "s": "Planetary nebula where fullerenes C60 and C70 were first found."}, {"n": "IC 4593", "u": "/e/planetary-nebulae/ic-4593/", "s": "A planetary nebula with a hot white dwarf and million-degree gas bubbles."}, {"n": "IC 5217", "u": "/e/planetary-nebulae/ic-5217/", "s": "Bipolar planetary nebula in Lacerta with a Wolf–Rayet central star."}, {"n": "Jonckheere 900", "u": "/e/planetary-nebulae/jonckheere-900/", "s": "Bipolar nebula misidentified as double star, rich in noble-gas lines."}, {"n": "Ka LMC 1", "u": "/e/planetary-nebulae/ka-lmc-1/", "s": "A faint, nitrogen-rich planetary nebula in the LMC's NGC 1866."}, {"n": "KjPn 8", "u": "/e/planetary-nebulae/kjpn-8/", "s": "Largest known bipolar planetary nebula with episodic precessing jets."}, {"n": "Little Dumbbell Nebula", "u": "/e/planetary-nebulae/little-dumbbell-nebula/", "s": "A bipolar planetary nebula in Perseus, discovered by Méchain in 1780."}, {"n": "Little Ghost Nebula", "u": "/e/planetary-nebulae/little-ghost-nebula/", "s": "A faint, round planetary nebula in Ophiuchus."}, {"n": "LoTr 1", "u": "/e/planetary-nebulae/lotr-1/", "s": "Bubble-shaped elliptical nebula with a binary central star system."}, {"n": "NGC 2818", "u": "/e/planetary-nebulae/ngc-2818/", "s": "A bipolar planetary nebula in Pyxis with disputed open cluster membership."}, {"n": "NGC 2867", "u": "/e/planetary-nebulae/ngc-2867/", "s": "Elliptical planetary nebula with a pulsating, hydrogen-deficient central star."}, {"n": "NGC 2899", "u": "/e/planetary-nebulae/ngc-2899/", "s": "Bipolar planetary nebula in Vela, shaped by a binary star system."}, {"n": "NGC 3132", "u": "/e/planetary-nebulae/ngc-3132/", "s": "A bipolar planetary nebula with a hot white dwarf central star."}, {"n": "NGC 3242", "u": "/e/planetary-nebulae/ngc-3242/", "s": "A planetary nebula resembling Jupiter, discovered by William Herschel in 1785."}, {"n": "NGC 5189", "u": "/e/planetary-nebulae/ngc-5189/", "s": "A planetary nebula with an S shape and a binary central star."}, {"n": "NGC 5315", "u": "/e/planetary-nebulae/ngc-5315/", "s": "Planetary nebula in Circinus with a hot, hydrogen-deficient central star."}, {"n": "NGC 5882", "u": "/e/planetary-nebulae/ngc-5882/", "s": "A small double-shell planetary nebula in Lupus with nitrogen enrichment."}, {"n": "NGC 6153", "u": "/e/planetary-nebulae/ngc-6153/", "s": "A bipolar nebula with extreme elemental overabundances."}, {"n": "NGC 6210", "u": "/e/planetary-nebulae/ngc-6210/", "s": "A bright planetary nebula with complex structure and high galactic latitude."}, {"n": "NGC 6302", "u": "/e/planetary-nebulae/ngc-6302/", "s": "A bipolar nebula with one of the hottest known central stars."}, {"n": "NGC 6445", "u": "/e/planetary-nebulae/ngc-6445/", "s": "Bipolar planetary nebula in Sagittarius, discovered by William Herschel."}, {"n": "NGC 6563", "u": "/e/planetary-nebulae/ngc-6563/", "s": "A planetary nebula in Sagittarius, discovered by James Dunlop in 1826."}, {"n": "NGC 6565", "u": "/e/planetary-nebulae/ngc-6565/", "s": "A triaxial planetary nebula with three ionization zones."}, {"n": "NGC 6572", "u": "/e/planetary-nebulae/ngc-6572/", "s": "A bright, young planetary nebula with multiple colorful nicknames."}, {"n": "NGC 6751", "u": "/e/planetary-nebulae/ngc-6751/", "s": "A planetary nebula with a complex bipolar structure and a hot central star."}, {"n": "NGC 6778", "u": "/e/planetary-nebulae/ngc-6778/", "s": "A disrupted planetary nebula with a close binary core."}, {"n": "NGC 6818", "u": "/e/planetary-nebulae/ngc-6818/", "s": "Planetary nebula in Sagittarius with knotty filaments and layered structure."}, {"n": "NGC 6891", "u": "/e/planetary-nebulae/ngc-6891/", "s": "Triple-shell planetary nebula in Delphinus with multiple ejection episodes."}, {"n": "NGC 6905", "u": "/e/planetary-nebulae/ngc-6905/", "s": "A planetary nebula with broad OVI emission and a [WO2] central star."}, {"n": "NGC 7027", "u": "/e/planetary-nebulae/ngc-7027/", "s": "A young, dense planetary nebula with complex structure and rich carbon chemistry."}, {"n": "NGC 7094", "u": "/e/planetary-nebulae/ngc-7094/", "s": "A planetary nebula in Pegasus with a hot transitional central star."}, {"n": "NGC 7354", "u": "/e/planetary-nebulae/ngc-7354/", "s": "A complex planetary nebula in Cepheus with binary star origins."}, {"n": "NGC 7662", "u": "/e/planetary-nebulae/ngc-7662/", "s": "A bright, blue planetary nebula in Andromeda with triple-shell structure."}, {"n": "Ou 5", "u": "/e/planetary-nebulae/ou-5/", "s": "A planetary nebula with a short-period eclipsing binary central star."}, {"n": "Owl Nebula", "u": "/e/planetary-nebulae/owl-nebula/", "s": "A planetary nebula with an owl-like face in Ursa Major."}, {"n": "Planetary nebula luminosity function", "u": "/e/planetary-nebulae/planetary-nebula-luminosity-function/", "s": "A secondary distance indicator using [O III] λ5007 emission."}, {"n": "Red Spider Nebula", "u": "/e/planetary-nebulae/red-spider-nebula/", "s": "A two-lobed planetary nebula with a hot white dwarf."}, {"n": "Sh 2-216", "u": "/e/planetary-nebulae/sh-2-216/", "s": "Closest planetary nebula to Earth, ancient and faint."}, {"n": "Southern Crab Nebula", "u": "/e/planetary-nebulae/southern-crab-nebula/", "s": "A southern-sky nebula resembling the Crab Nebula."}, {"n": "Stingray Nebula", "u": "/e/planetary-nebulae/stingray-nebula/", "s": "The youngest-known planetary nebula, first observed in the 1980s."}, {"n": "Vy 1-2", "u": "/e/planetary-nebulae/vy-1-2/", "s": "Planetary nebula with faint knots and a bright elliptical ring."}, {"n": "WeBo 1", "u": "/e/planetary-nebulae/webo-1/", "s": "Faint ring-shaped planetary nebula near the Heart Nebula."}, {"n": "Zanstra method", "u": "/e/planetary-nebulae/zanstra-method/", "s": "Method to determine central star temperature of planetary nebulae."}, {"n": "Abell Catalog of Planetary Nebulae", "u": "/e/planetary-nebulae/abell-catalog-of-planetary-nebulae/", "s": "86 entries thought to be planetary nebulae, created in 1966."}, {"n": "Abell 30", "u": "/e/planetary-nebulae/abell-30/", "s": "A born-again planetary nebula with hydrogen-depleted knots."}, {"n": "Abell 35", "u": "/e/planetary-nebulae/abell-35/", "s": "A nebula with a bow shock and a binary star nucleus."}, {"n": "Abell 39", "u": "/e/planetary-nebulae/abell-39/", "s": "A nearly perfect spherical planetary nebula in Hercules."}, {"n": "Abell 48", "u": "/e/planetary-nebulae/abell-48/", "s": "A heavily reddened planetary nebula with a rare [WN4] central star."}]