1. A galaxy having a spiral structure; arms containing younger stars spiral out from old stars at the centre
   - spiral nebula

Derived forms: spiral galaxies

Type of: extragalactic nebula, galaxy

Encyclopedia: Spiral galaxy

• Periactin
• perianal
• perianth
• periapsis
• periapt
• periarterial plexus
• periarteritis
• periarteritis nodosa
• periastron
• Pericallis
• Pericallis cruenta
• Pericallis hybrida
• pericardiac
• pericardial
• pericardial cavity
• pericardial sac
• pericardial space
• pericardial vein
• pericarditis
• pericardium
• pericarp
• pericementoclasia
• pericenter
• pericentre
• perichondrium