Astrophysics (Index)About


(measure of brightness)

Luminosity is the total rate of energy emission by a star or other astronomical object, often expressed in joules per second, i.e., watts or in solar luminosities (LSun). Thus it is the power of the starshine. Absolute bolometric magnitude is an alternate measure of the same thing, expressed logarithmically. The term is also used in discussions of stellar structure to refer to the energy produced/released within an inner portion of the star, such as citing the luminosity produced within a particular radius of the center, e.g., the stellar core.

Generally when unqualified and not in a context that implies otherwise, luminosity is intended to mean bolometric luminosity, i.e., energy emitted over all wavelengths. The term may be used for a single wavelength (monochromatic luminosity) or over some wavelength range or via some passband (filter).

Further reading:

Referenced by pages:
active galaxy
AD Leonis (AD Leo)
active galactic nucleus (AGN)
Algol (Beta Per)
Alpha Centauri (α Centauri)
AU Microscopii (AU Mic)
Barnard's Star
BA supergiant
Beta Centauri
binary star
broad-line region (BLR)
blue horizontal branch (BHB)
bolometric luminosity (LBol)
bolometric magnitude (Mbol)
Cepheid variable (CEP)
conditional luminosity function (CLF)
cluster radius
color-magnitude diagram (CMD)
compact object (CO)
David Dunlap Observatory Catalog (DDO)
distance modulus (μ)
dwarf spheroidal galaxy (dSph)
Eddington luminosity
Epsilon Eridani
Epsilon Indi (ε Indi)
equilibrium temperature (Teq)
Faber-Jackson relation (FJR)
flux-weighted gravity-luminosity relationship (FGLR)
Fanaroff-Riley classification
galaxy classification
galaxy group
giant star
globular cluster (GC)
halo abundance matching (HAM)
Hayashi limit
horizontal branch (HB)
heartbeat star
Henyey track
Herbig AeBe star (HAeBe)
Hess diagram
HII region (HII)
hyperluminous infrared galaxy (HLIRG)
HR 8799
H-R diagram (HRD)
Hubble expansion
infrared (IR)
Kapteyn's Star
K-type star (K)
Kelvin-Helmholtz mechanism
Kelvin-Helmholtz timescale (KH timescale)
Lacaille 9352
Lalande 21185
luminous blue variable (LBV)
LHS 1140
light cone
luminous infrared galaxy (LIRG)
luminous red nova (LRN)
low-surface-brightness galaxy (LSB galaxy)
luminosity class
luminosity density
luminosity distance (dL)
luminosity function (LF)
Luyten 726-8
mass-luminosity relation
mass-to-light ratio (M/L)
M-type star (M)
molecular cloud
monochromatic luminosity
obscured fraction-luminosity relation
O-type star (O)
planetary nebula luminosity function (PNLF)
radiant flux
radio source counts
red clump (RC)
red giant
relativistic beaming
red-giant branch (RGB)
Ross 154
Ross 248
RR Lyrae variable (RRL)
Salpeter timescale
SMBH formation
supernova light curve (SN light curve)
spectral class
spectral type
spin-down luminosity
stellar distance determination
stellar evolution
stellar luminosity determination
stellar mass determination
stellar parameter determination
stellar radius determination
stellar structure
subdwarf (sd)
SuperCOSMOS Sky Survey (SSS)
surface density (Σ)
synchrotron radiation
Teegarden's Star
Tully-Fisher relation (TFR)
tidal migration
timescale (t)
tip of the red-giant branch (TRGB)
turn-off point (TO)
Type Ia supernova
ultra diffuse galaxy (UDG)
van den Bergh galaxy classification
Vogt-Russell theorem (VR theorem)
volume weighting
watt (W)
white dwarf (WD)
Wilson-Bappu effect
wind-momentum luminosity relationship (WLR)
Wolf-Rayet star
WR 104
WR 140
X-ray luminosity function (XLF)