Astrophysics (index)about

light-year

(ly)
(distance that light travels in a year)

A light-year is the distance that light travels in a year. The count of light-years to something viewed also represents how far into the past the observation is viewing. In the science of astronomy/astrophysics, the unit light-year is often used in communications to the public, but the unit parsec (pc) is used in calculations and scientific communication.

Equivalence:


(distance,unit,astronomy)
http://en.wikipedia.org/wiki/Light-year

Referenced by:
Alpha Centauri
Automated Planet Finder (APF)
astronomical quantities
astronomical unit (AU)
AzTEC-3
Barnard's Star
Canis Major Dwarf Galaxy
Cassiopeia A
Circinus Galaxy (ESO 97-G13)
Coma Supercluster
Comet Galaxy
Epsilon Eridani
Epsilon Indi (ε Indi)
ESO 137-001
47 Tucanae (47 Tuc)
Great Attractor
Great Wall
Hercules-Corona Borealis Great Wall (Her-CrB GW)
HI supershell
Hyades Cluster
Hydra-Centaurus Supercluster
IC 342
J1407
Kapteyn's Star
LHS 1140
Large Magellanic Cloud (LMC)
Local Group (LG)
Luyten 726-8
Messier 100 (M100)
Pinwheel Galaxy (M101)
Sombrero Galaxy (M104)
Messier 15 (M15)
Andromeda (M31)
Triangulum Galaxy (M33)
Whirlpool Galaxy (M51a)
M64
Messier 74 (M74)
M82
Messier 84 (M84)
M87
Milky Way
NANOGrav
NGC 1600
NGC 253
NGC 2770
NGC 3201
NGC 3314
Spindle Galaxy (NGC 5866)
OB association
Orion
parsec (pc)
Perseus-Pisces Supercluster
pulsar timing array (PTA)
quasar (QSO)
redshift (z)
Rho Ophiuchi Cloud Complex
Sagittarius Dwarf Irregular Galaxy (SagDIG)
Sagittarius Dwarf Elliptical Galaxy (Sgr dE)
Scholz's Star
Sculptor Wall
Sloan Great Wall (SGW)
Small Magellanic Cloud (SMC)
SN 1987A (1987A)
SN 2014J
Sun
supercluster
3C 273
3C 295
3C 48
TW Hydrae (TW Hya)
Vega
void
WISE 1506+7027
Wolf 359

index