List of common astronomy symbols

This is a compilation of symbols commonly used in astronomy, particularly professional astronomy. == Age (stellar) == τ - age == Astrometry parameters == Astrometry parameters Rv - radial velocity cz - apparent radial velocity z - Redshift μ - proper motion π - parallax J - epoch α - Right Ascension δ - Declination λ - Ecliptic longitude β - Ecliptic latitude l - Galactic longitude b - Galactic latitude Δ - Distance from Earth ø - Geographical or astronomical latitude == Cosmological parameters == Cosmological parameters h - dimensionless Hubble parameter H0 - Hubble constant Λ - cosmological constant Ω - density parameter ρ - density ρc - critical density z - redshift == Distance description == Distance description for orbital and non-orbital parameters: d - distance d - in km = kilometer d - in mi = mile d - in AU = astronomical unit d - in ly = light-year d - in pc = parsec d - in kpc = kiloparsec (1000 pc) DL - luminosity distance, obtaining an objects distance using only visual aspects == Galaxy comparison == Galaxy type and spectral comparison: see galaxy morphological classification == Luminosity comparison == Luminosity comparison: LS, L☉ - luminosity of the Sun Luminosity of certain object: Lacc - accretion luminosity Lbol - bolometric luminosity == Mass comparison == Mass comparison: ME, M🜨 - mass of Earth MJ, M♃ - mass of Jupiter MS, M☉ - mass of the Sun Mass of certain object: M● - mass of black hole Macc - mass of accretion disc == Metallicity comparison == Metallicity comparison: [Fe/H] - Ratio of Iron to Hydrogen.

Source: Wikipedia — List of common astronomy symbols (CC BY-SA 4.0)