Hot Neptune
[5] If these planets formed ex situ, i.e., by migrating to their current locations while growing, they may contain large quantities of frozen volatiles and amorphous ices.[3] Yet, regardless of the mode of formation, hot Neptunes should contain large fractions (by mass) of gases, primarily hydrogen and helium, which also account for most of their volume.[6][7] LTT 9779 b (Cuancoá) is the first ultra-hot Neptune discovered with an orbital period of 19 hours and an atmospheric temperature of over 1700 degrees Celsius.Being so close to its star and with a mass around twice that of Neptune, its atmosphere should have evaporated into space so its existence requires an unusual explanation.It orbits Vega, an A-class star, every 2.43 days, and with a temperature of about 2500 degrees Celsius would be the second-hottest planet on record if confirmed.
giant planetNeptuneUranusGliese 436 bexoplanetMilky Wayin situtransitingplanetsHAT-P-11bMu Arae cKepler-56bMercuryvolatilesamorphous icesrefractory materialsLTT 9779 bHelium planetHot JupiterMini-NeptuneNeptunian desertOcean worldHycean planetSuper-EarthBibcodeCentauri DreamsPlanetDefinitionPlanetary scienceExoplanet orbital and physical parametersMethods of detecting exoplanetsPlanetary systemPlanet-hosting starsTerrestrialCarbon planetCoreless planetDesert planetDwarf planetIce planetIron planetLava planetMega-EarthSub-EarthGaseousEccentric JupiterGas giantIce giantSuper-JupiterSuper-NeptuneSuper-puffUltra-hot JupiterUltra-hot NeptuneBlanetBrown dwarfChthonian planetCircumbinary planetCircumtriple planetDisrupted planetDouble planetEcumenopolisEyeball planetMesoplanetPlanemoPlanetesimalProtoplanetPulsar planetSub-brown dwarfSub-NeptuneToroidal planetUltra-cool dwarfUltra-short period planet (USP)Formation and evolutionAccretionAccretion diskAsteroid beltCircumplanetary diskCircumstellar discCircumstellar envelopeCosmic dustDebris diskDetached objectExozodiacal dustExtraterrestrial materialsExtraterrestrial sample curationGiant-impact hypothesisGravitational collapseHills cloudInternal structureInterplanetary dust cloudInterplanetary mediumInterplanetary spaceInterstellar cloudInterstellar dustInterstellar mediumKuiper beltList of interstellar and circumstellar moleculesMolecular cloudNebular hypothesisOort cloudOuter spacePlanetary migrationProtoplanetary diskRing systemRubble pileSample-return missionScattered discStar formationSystemsExocometInterstellarExomoonTidally detachedRogue planetPulsarDetectionAstrometryMicrolensingPolarimetryRadial velocityTransit-timing variationHabitabilityAstrobiologyAstrooceanographyCircumstellar habitable zoneEarth analogExtraterrestrial liquid water