Lably
Skip to contentR
- R SerpentisR Serpentis is a Mira variable type star in the equatorial constellation of Serpens. It ra
- R-processNucleosynthesis pathway
- R. Paul ButlerAmerican astronomer
- R136Super star cluster in the constellation Dorado, in the Large Magellanic Cloud
- R136a1Wolf–Rayet star in the constellation Dorado
- Radcliffe waveThe Radcliffe wave is a neighbouring coherent gaseous structure in the Milky Way, dotted w
- Radial trajectoryIn astrodynamics and celestial mechanics a radial trajectory is a Kepler orbit with zero a
- Radial velocityVelocity of an object as the rate of distance change between the object and a point
- Radiant (meteor shower)Celestial point in the sky from which meteors appear to originate
- Radiative zoneRegion of a star
- Radio astronomySubfield of astronomy that studies celestial objects at radio frequencies
- Radio EnciclopediaRadio Enciclopedia (Spanish: Enciclopedia de radio) is a classical / beautiful music radio
- Radio galaxyType of active galaxy that is very luminous at radio wavelengths
- Radio spectrum pollutionDeviation of radio waves beyond allocations
- Radio-quiet neutron starNeutron star that does not emit radio waves
- Ralph (New Horizons)Ralph is a science instrument aboard the robotic New Horizons spacecraft, which was launch
- Ralph Belknap BaldwinAmerican planetary scientist
- Ralph CopelandEnglish astronomer
- RameruptRamerupt (French pronunciation: ) is a commune in the Aube department in north-central Fra
- Rapid Eye Mount telescopeThe Rapid Eye Mount telescope (REM) is a fully automatic, 60 cm aperture telescope located
- Rare Earth hypothesisHypothesis that planets with complex life are extremely rare
- Ras ThavasRas Thavas is a fictional character created by Edgar Rice Burroughs in his 1927 novel The
- Ray systemRadial streaks of material thrown out during formation of an impact crater
- Reber Radio TelescopeThe Reber Radio Telescope is a historic radio telescope, located at the Green Bank Observa
- Recessional velocityRate at which an astronomical object moves away from an observer
- Recombination (cosmology)Cosmological epoch c. 370,000 years after the Big Bang
- Red dwarfDim, low mass stars on the main sequence
- Red giantType of large cool star
- Red Square NebulaThe Red Square Nebula is a celestial object located in the area of the sky occupied by sta
- Red supergiantStars with a supergiant luminosity class with a spectral type of K or M
- Red-giant branchPortion of the giant branch before helium ignition
- RedshiftChange in wavelength of light
- Reflection nebulaClouds of interstellar dust which reflect the light of nearby stars
- Regular moonSatellites that formed around their parent planet
- RegulusBrightest star in the constellation Leo
- ReionizationCosmological process in the early universe
- Relativistic beamingChange in luminosity of a moving object due to special relativity
- Resonant trans-Neptunian objectTrans-Neptunian object in a mean-motion orbital resonance with Neptune
- Resource ProspectorResource Prospector is a cancelled mission concept by NASA of a rover that would have perf
- ReticulumConstellation in the southern celestial hemisphere
- Retrograde and prograde motionRelative directions of orbit or rotation
- Return of Apollo 15 to EarthAfter the Apollo 15 LM Falcon lifted from the lunar surface on August 2, 1971, it rendezvo
- Rhea (moon)Second-largest moon of Saturn
- Rho CassiopeiaeYellow hypergiant star in the constellation Cassiopeia
- Rho Ophiuchi cloud complexInterstellar cloud
- Rho VirginisRho Virginis (ρ Vir, ρ Virginis) is the Bayer designation for a star in the constellation
- Richard B. DunnRichard Brandner Dunn (December 14, 1927 – September 29, 2005) was an American solar physi
- Richard Ellis (astronomer)Welsh astronomer (born 1950)
- Richard Green (astronomer)American astronomer
- Richard HuziakCanadian astronomer
- Richard KowalskiRichard A. Kowalski (born 1963) is an American astronomer who has discovered numerous aste
- Richard P. BinzelAmerican astronomer
- RigelBrightest star in the constellation Orion
- Right ascensionAstronomical equivalent of longitude
- Ring galaxyGalaxy with an annular appearance
- Ring NebulaPlanetary nebula in Lyra
- Ring systemRing of cosmic dust orbiting an astronomical object
- Rings of JupiterThe rings of Jupiter are a system of faint planetary rings. The Jovian rings were the thir
- Rings of NeptuneThe rings of Neptune consist primarily of five principal rings. They were first discovered
- Rings of SaturnSaturn has the most extensive and complex ring system of any planet in the Solar System. T
- Rings of UranusThe rings of Uranus consist of 13 planetary rings. They are intermediate in complexity bet
- Robert D. StephensAmerican astronomer
- Robert Grant AitkenAmerican astronomer
- Robert Sutton HarringtonAmerican astronomer (1942–1993)
- Robert T. A. InnesSouth African astronomer (1861–1933)
- Robin CanupAmerican astrophysicist
- Robotic telescopeTelescope that makes observations without the intervention of a human
- Roche limitOrbital radius at which a satellite might break up due to gravitational force
- Roche lobeGravitationally-binding region around a star in a binary system
- Roger AngelBritish-born American astronomer
- Rogue planetPlanet not gravitationally bound to a star
- Romanization of GreekRendering Greek in Latin characters
- Rome ObservatoryThe Astronomical Observatory of Rome (Osservatorio Astronomico di Roma in Italian) is one
- Roque de los Muchachos ObservatoryAstronomical observatory on La Palma, Canary Islands
- Rosalind (moon)Rosalind is an inner satellite of Uranus. It was discovered from the images taken by Voyag
- Rosemary Hill ObservatoryRosemary Hill Observatory (RHO) is an astronomical observatory located near the town of Br
- Rosette NebulaEmission nebula in the constellation Monoceros
- Ross 695Ross 695, also known as Gliese 465, is a red dwarf star in the constellation Corvus. At ap
- Rossi X-ray Timing ExplorerThe Rossi X-ray Timing Explorer (RXTE) was a NASA satellite that observed the time variati
- Rotation periodTime that it takes to complete one rotation relative to the background stars
- Royal Astronomical SocietyBritish learned society and charity
- Royal Observatory of BelgiumObservatory
- Royal Observatory, GreenwichObservatory in London, England
- Rp-processProcess of nucleosynthesis
- RR CaeliRR Caeli is an eclipsing binary star system, located 69 light-years from Earth in the cons
- RR LyraeRR Lyrae is a variable star in the Lyra constellation, figuring in its west near to Cygnus
- RR Lyrae variableType of variable star
- RR PictorisRR Pictoris, also known as Nova Pictoris 1925, is a cataclysmic variable star system that
- RR TelescopiiRR Telescopii is a symbiotic nova in the southern constellation Telescopium. It was record
- RS Canum Venaticorum variableAn RS Canum Venaticorum variable is a type of variable star. The variable type consists of
- RS TelescopiiRS Telescopii, abbreviated RS Tel, is a variable star in the southern constellation of Tel
- RSGC1RSGC1 (Red Supergiant Cluster 1) is a young massive open cluster in the Milky Way galaxy.
- RSGC3RSGC3 (Red Supergiant Cluster 3) is a young massive open cluster belonging to the Milky Wa
- Ruach PlanitiaWalled plain on Triton
- Rubble pileCelestial body composed of many pieces of rock held together by gravity
- Runaway greenhouse effectClimatic effect causing a planet's atmosphere to trap heat and prevent cooling
- Russell Merle GenetAmerican astronomer (born 1940)
- Russell W. PorterAmerican artist, astronomer, and explorer
- RV Tauri variableRV Tauri variables are luminous variable stars that have distinctive light variations with
