Linked from

The 13 pages that link to Light-year, each with the reason it gives.

• Speed of lightRelated: It expresses astronomical distances directly using the vacuum speed of light.

• Andromeda GalaxyRelated: Andromeda’s distance is expressed in light-years because ordinary units are impractical at galactic scales.

• Lookback timeRelated: A light-year converts travel time into a distance, but does not by itself give cosmic lookback time.

• Interstellar travelRelated: Nearby star systems remain several light-years away even when measured with this unit.

• Cartwheel GalaxyRelated: The Cartwheel’s distance is commonly expressed in hundreds of millions of light-years.

• Messier 81Related: M81’s distance is expressed in light-years.

• Epsilon EridaniRelated: The system’s distance makes it one of the nearest planetary-system laboratories.

• Messier 13Related: Its distance of roughly 22,000 light-years expresses how far its light has traveled.

• Messier 77Related: Its distance from Earth is commonly expressed in light-years.

• Astronomical system of unitsRelated: It is more convenient than the astronomical unit for interstellar distances.

• Epsilon Canis MajorisRelated: The system’s distance from Earth is expressed in light-years.