light-year | 1 ly | 2 ly | 3 ly | 4 ly | 5 ly | 6 ly | 7 ly | 8 ly | 9 ly | 10 ly | 11 ly | 12 ly | 13 ly | 14 ly | 15 ly | 16 ly | 17 ly | 18 ly | 19 ly | 20 ly | 21 ly | 22 ly | 23 ly | 24 ly | 25 ly | 26 ly | 27 ly | 28 ly | 29 ly | 30 ly | 31 ly | 32 ly | 33 ly | 34 ly | 35 ly | 36 ly | 37 ly | 38 ly | 39 ly | 40 ly | 41 ly | 42 ly | 43 ly | 44 ly | 45 ly | 46 ly | 47 ly | 48 ly | 49 ly | 50 ly | 51 ly | 52 ly | 53 ly | 54 ly | 55 ly | 56 ly | 57 ly | 58 ly | 59 ly | 60 ly | 61 ly | 62 ly | 63 ly | 64 ly | 65 ly | 66 ly | 67 ly | 68 ly | 69 ly | 70 ly | 71 ly | 72 ly | 73 ly | 74 ly | 75 ly | 76 ly | 77 ly | 78 ly | 79 ly | 80 ly | 81 ly | 82 ly | 83 ly | 84 ly | 85 ly | 86 ly | 87 ly | 88 ly | 89 ly | 90 ly | 91 ly | 92 ly | 93 ly | 94 ly | 95 ly | 96 ly | 97 ly | 98 ly | 99 ly | 100 ly |
astronomical unit | 63,239.7263451 AU | 126,479.4526902 AU | 189,719.1790353 AU | 252,958.9053805 AU | 316,198.6317256 AU | 379,438.3580707 AU | 442,678.0844158 AU | 505,917.8107609 AU | 569,157.5371060 AU | 632,397.2634511 AU | 695,636.9897962 AU | 758,876.7161413 AU | 822,116.4424865 AU | 885,356.1688316 AU | 948,595.8951767 AU | 1,011,835.6215218 AU | 1,075,075.3478669 AU | 1,138,315.074212 AU | 1,201,554.8005571 AU | 1,264,794.5269022 AU | 1,328,034.2532473 AU | 1,391,273.9795925 AU | 1,454,513.7059376 AU | 1,517,753.4322827 AU | 1,580,993.1586278 AU | 1,644,232.8849729 AU | 1,707,472.611318 AU | 1,770,712.3376631 AU | 1,833,952.0640082 AU | 1,897,191.7903534 AU | 1,960,431.5166985 AU | 2,023,671.2430436 AU | 2,086,910.9693887 AU | 2,150,150.6957338 AU | 2,213,390.4220789 AU | 2,276,630.148424 AU | 2,339,869.8747691 AU | 2,403,109.6011142 AU | 2,466,349.3274594 AU | 2,529,589.0538045 AU | 2,592,828.7801496 AU | 2,656,068.5064947 AU | 2,719,308.2328398 AU | 2,782,547.9591849 AU | 2,845,787.68553 AU | 2,909,027.4118751 AU | 2,972,267.1382202 AU | 3,035,506.8645654 AU | 3,098,746.5909105 AU | 3,161,986.3172556 AU | 3,225,226.0436007 AU | 3,288,465.7699458 AU | 3,351,705.4962909 AU | 3,414,945.222636 AU | 3,478,184.9489811 AU | 3,541,424.6753263 AU | 3,604,664.4016714 AU | 3,667,904.1280165 AU | 3,731,143.8543616 AU | 3,794,383.5807067 AU | 3,857,623.3070518 AU | 3,920,863.0333969 AU | 3,984,102.759742 AU | 4,047,342.4860871 AU | 4,110,582.2124323 AU | 4,173,821.9387774 AU | 4,237,061.6651225 AU | 4,300,301.3914676 AU | 4,363,541.1178127 AU | 4,426,780.8441578 AU | 4,490,020.5705029 AU | 4,553,260.296848 AU | 4,616,500.0231932 AU | 4,679,739.7495383 AU | 4,742,979.4758834 AU | 4,806,219.2022285 AU | 4,869,458.9285736 AU | 4,932,698.6549187 AU | 4,995,938.3812638 AU | 5,059,178.1076089 AU | 5,122,417.833954 AU | 5,185,657.5602992 AU | 5,248,897.2866443 AU | 5,312,137.0129894 AU | 5,375,376.7393345 AU | 5,438,616.4656796 AU | 5,501,856.1920247 AU | 5,565,095.9183698 AU | 5,628,335.6447149 AU | 5,691,575.3710601 AU | 5,754,815.0974052 AU | 5,818,054.8237503 AU | 5,881,294.5500954 AU | 5,944,534.2764405 AU | 6,007,774.0027856 AU | 6,071,013.7291307 AU | 6,134,253.4554758 AU | 6,197,493.1818209 AU | 6,260,732.9081661 AU | 6,323,972.6345112 AU |
The light-year is a unit of length used to express astronomical distances. It is about 9.5 quadrillion metres or 5.9 trillion miles. As defined by the International Astronomical Union (IAU), a light-year is the distance that light travels in vacuum in one Julian year (365.25 days). Because it includes the word "year", the term light-year is sometimes misinterpreted as a unit of time.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
light-year | ly | ≡ Distance light travels in vacuum in 365.25 days | = 9.4607304725808×1015 m | Science - Astronomy (Length) |
light-years | astronomical units | light-years | astronomical units |
---|---|---|---|
1 | = 63239.726345112 | 4 | = 252958.90538045 |
1.5 | = 94859.589517668 | 4.5 | = 284578.768553 |
2 | = 126479.45269022 | 5 | = 316198.63172556 |
2.5 | = 158099.31586278 | 5.5 | = 347818.49489811 |
3 | = 189719.17903534 | 6 | = 379438.35807067 |
The astronomical unit (symbol: au or ua) is a unit of length, roughly the distance from Earth to the Sun. However, that distance varies as Earth orbits the Sun, from a maximum (aphelion) to a minimum (perihelion) and back again once a year. Originally conceived as the average of Earth's aphelion and perihelion, it is now defined as exactly 149 597 870 700 metres (about 150 million kilometres, or 93 million miles). The astronomical unit is used primarily as a convenient yardstick for measuring distances within the Solar System or around other stars. However, it is also a fundamental component in the definition of another unit of astronomical length, the parsec.
Name of unit | Symbol | Definition | Relation to SI units | Unit System |
---|---|---|---|---|
astronomical unit | AU | ≡ 149 597 870 700 m ≈ Distance from Earth to Sun | ≡ 149 597 870 700 m | Science - Astronomy (Length) |
astronomical units | light-years | astronomical units | light-years |
---|---|---|---|
1 | = 1.5812845149626E-5 | 4 | = 6.3251380598506E-5 |
1.5 | = 2.371926772444E-5 | 4.5 | = 7.1157803173319E-5 |
2 | = 3.1625690299253E-5 | 5 | = 7.9064225748132E-5 |
2.5 | = 3.9532112874066E-5 | 5.5 | = 8.6970648322945E-5 |
3 | = 4.7438535448879E-5 | 6 | = 9.4877070897758E-5 |
light-years | astronomical units |
---|---|
1 | = 63,239.7263451 |
1.5812845149626 × 10-5 | = 1 |
Symbol | Definition |
---|---|
≡ | exactly equal |
≈ | approximately equal to |
= | equal to |
digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |