Astronomy

Articles about stars, planets, space and the universe.

Articles in this category: 1040 Updated: April 29, 2026 Page 14 / 22

NGC 3521

NGC 3521 — Flocculent Spiral Galaxy in Leo

NGC 3603-B

NGC 3603-B (HD 97950B): a massive WN6h Wolf–Rayet star

NGC 4102

NGC 4102: Spiral galaxy in Ursa Major

NGC 4526

NGC 4526 — Lenticular galaxy in the Virgo region

NGC 4605

NGC 4605 — a spiral galaxy in Ursa Major

NGC 5907

NGC 6025

NGC 6193

NGC 6302

NGC 6334

NGC 6503

NGC 6503 — a nearby dwarf spiral galaxy in Draco

NGC 6543

NGC 6543 (Cat's Eye Nebula)

NGC 6559

NGC 6559 — a star-forming nebula in Sagittarius

NGC 6946

NGC 6946 (Fireworks Galaxy) — a nearby spiral with frequent supernovae

NGC 7049

NGC 7049 — early-type galaxy with a striking dust ring in Indus

NGC 7090

NGC 7090 — an edge-on spiral galaxy in Indus

NGC 7538

NGC 7538 — Star-forming Nebula in Cepheus

Nix (moon)

Nix (moon) — small irregular satellite of Pluto

NML Cygni

Non-periodic comet

Non-periodic comet (single-apparition and long‑period comets)

Norma

Norma (constellation)

Norma Cluster

Norma Cluster (Abell 3627) — a massive galaxy cluster near the Great Attractor

North America nebula

North America Nebula (NGC 7000)

Nova

Nozomi (spacecraft)

Nozomi — Japan’s early Mars probe (PLANET-B)

OB star

Oberon (moon)

Observable universe

Observatory

Occultation

Occultation (astronomy and general): definition, types, and significance

Octans

Octans — Southern Constellation Marking the South Celestial Pole

Ohzora

Ohzora — Japanese scientific satellite (launched 14 February 1984)

Olympus Mons

Omega Centauri

Omega Centauri (ω Centauri, NGC 5139) — largest globular cluster of the Milky Way

Omega Nebula

Omega Nebula (M17) — the Swan Nebula, a bright H II region

Omniverse

Oort cloud

Open star cluster

Ophelia (moon)

Ophiuchus

Ophiuchus: the Serpent-Bearer constellation

Ophiuchus Supercluster explosion

Ophiuchus Supercluster Explosion: the largest known cosmic eruption

Opposition (astronomy and astrology)

Orbit

Orbital

Orbital eccentricity

Orbital inclination

Orbital period