<Tr> <Td> 7016813622820641948 ♠ 8.60 × 10 ly </Td> <Td> Sirius, the brightest star of the night sky . Twice as massive and 25 times more luminous than the Sun, it outshines more luminous stars due to its relative proximity . </Td> </Tr> <Tr> <Td> 7017112582692623711 ♠ 11.90 × 10 ly </Td> <Td> HD 10700 e, an extrasolar candidate for a habitable planet . 6.6 times as massive as the earth, it is in the middle of the habitable zone of star Tau Ceti . </Td> </Tr> <Tr> <Td> 7017193944974687906 ♠ 20.5 × 10 ly </Td> <Td> Gliese 581, a red - dwarf star with several detectable exoplanets . </Td> </Tr> <Tr> <Td> 7018293282644650004 ♠ 310 × 10 ly </Td> <Td> Canopus, second in brightness in the terrestrial sky only to Sirius, a type F supergiant 7004150000000000000 ♠ 15 000 times more luminous than the Sun . </Td> </Tr>

Although a light-year is a unit of distance it is also helpful in determining