Astronomy
Articles about stars, planets, space and the universe.
Pyxis
Pyxis (constellation)
Quasar
Quasar: powerful active galactic nuclei and their cosmic role
Queen of Outer Space
Queen of Outer Space (1958 film)
R Apodis
R Doradus
R Doradus — a nearby red giant with an unusually large apparent size
R Leporis
R Scuti
R Scuti (variable star in Scutum)
R136a1
R136a1 — Extremely Massive Wolf–Rayet Star in the Tarantula Nebula
R136c
R136c — a very massive Wolf–Rayet star in the R136 cluster
Radio astronomy
Radio galaxy
Radio telescope
Red dwarf
Red dwarf star
Red giant
Red giant (stellar evolution stage)
Red shift
Red shift in astronomy
Red shift is the lengthening of light's wavelength from distant sources. It reveals motion, cosmic expansion, and gravity effects and is measured by comparing shifted spectral line
Red supergiant
Reflection nebula
A reflection nebula is an interstellar cloud of dust visible by scattering starlight. It is often blue, differs from emission nebulae, and frequently occurs near star-forming regio
Regulus
Regulus (Alpha Leonis): the brightest star of Leo
Relativistic jet
Reticulum
Reticulum (constellation)
Retrograde and direct motion
Retrograde and Direct Motion in Astronomy
Rhea (moon)
Rhea: Saturn's Second-Largest Moon
Rho Cassiopeiae
Rigel
Rigel (Beta Orionis): a blue supergiant in Orion
Right ascension
Ring galaxy
Ring galaxies: structure, formation, and notable examples
Rings of Jupiter
Rings of Neptune
Rings of Rhea
Rings of Rhea: the proposed ring system around Saturn’s moon
Rings of Saturn
Rings of Uranus
Roche limit
Roman calendar
Rosalind (moon)
Rosalind (moon) — a small inner satellite of Uranus
Rosetta (spacecraft)
Rosetta (spacecraft): ESA mission to comet 67P/Churyumov–Gerasimenko
Ross 154
Ross 154 — Nearby Flare M Dwarf in Sagittarius
Ross 248
Ross 248 (HH Andromedae): a nearby red-dwarf flare star
Rotation period
Rotation period (astronomy)
Rover (space exploration)
RR Lyrae
RR Lyrae — prototype of RR Lyrae variable stars
RS Persei
RS Persei: a red supergiant variable in the Double Cluster
RSGC1
RSGC1 — Massive Young Red Supergiant Cluster in Scutum
RW Cephei
RW Cephei — an orange hypergiant in the constellation Cepheus