| astronomical unit | 1 AU | 2 AU | 3 AU | 4 AU | 5 AU | 6 AU | 7 AU | 8 AU | 9 AU | 10 AU | 11 AU | 12 AU | 13 AU | 14 AU | 15 AU | 16 AU | 17 AU | 18 AU | 19 AU | 20 AU | 21 AU | 22 AU | 23 AU | 24 AU | 25 AU | 26 AU | 27 AU | 28 AU | 29 AU | 30 AU | 31 AU | 32 AU | 33 AU | 34 AU | 35 AU | 36 AU | 37 AU | 38 AU | 39 AU | 40 AU | 41 AU | 42 AU | 43 AU | 44 AU | 45 AU | 46 AU | 47 AU | 48 AU | 49 AU | 50 AU | 51 AU | 52 AU | 53 AU | 54 AU | 55 AU | 56 AU | 57 AU | 58 AU | 59 AU | 60 AU | 61 AU | 62 AU | 63 AU | 64 AU | 65 AU | 66 AU | 67 AU | 68 AU | 69 AU | 70 AU | 71 AU | 72 AU | 73 AU | 74 AU | 75 AU | 76 AU | 77 AU | 78 AU | 79 AU | 80 AU | 81 AU | 82 AU | 83 AU | 84 AU | 85 AU | 86 AU | 87 AU | 88 AU | 89 AU | 90 AU | 91 AU | 92 AU | 93 AU | 94 AU | 95 AU | 96 AU | 97 AU | 98 AU | 99 AU | 100 AU |
| light-hour | 0.1386124 light-hour | 0.2772249 light-hour | 0.4158373 light-hour | 0.5544498 light-hour | 0.6930622 light-hour | 0.8316746 light-hour | 0.9702871 light-hour | 1.1088995 light-hour | 1.2475120 light-hour | 1.3861244 light-hour | 1.5247368 light-hour | 1.6633493 light-hour | 1.8019617 light-hour | 1.9405742 light-hour | 2.0791866 light-hour | 2.2177990 light-hour | 2.3564115 light-hour | 2.4950239 light-hour | 2.6336364 light-hour | 2.7722488 light-hour | 2.9108612 light-hour | 3.0494737 light-hour | 3.1880861 light-hour | 3.3266986 light-hour | 3.4653110 light-hour | 3.6039234 light-hour | 3.7425359 light-hour | 3.8811483 light-hour | 4.0197608 light-hour | 4.1583732 light-hour | 4.2969856 light-hour | 4.4355981 light-hour | 4.5742105 light-hour | 4.7128230 light-hour | 4.8514354 light-hour | 4.9900478 light-hour | 5.1286603 light-hour | 5.2672727 light-hour | 5.4058852 light-hour | 5.5444976 light-hour | 5.6831100 light-hour | 5.8217225 light-hour | 5.9603349 light-hour | 6.0989474 light-hour | 6.2375598 light-hour | 6.3761722 light-hour | 6.5147847 light-hour | 6.6533971 light-hour | 6.7920096 light-hour | 6.9306220 light-hour | 7.0692344 light-hour | 7.2078469 light-hour | 7.3464593 light-hour | 7.4850718 light-hour | 7.6236842 light-hour | 7.7622966 light-hour | 7.9009091 light-hour | 8.0395215 light-hour | 8.1781340 light-hour | 8.3167464 light-hour | 8.4553588 light-hour | 8.5939713 light-hour | 8.7325837 light-hour | 8.8711962 light-hour | 9.0098086 light-hour | 9.1484210 light-hour | 9.2870335 light-hour | 9.4256459 light-hour | 9.5642584 light-hour | 9.7028708 light-hour | 9.8414832 light-hour | 9.9800957 light-hour | 10.1187081 light-hour | 10.2573206 light-hour | 10.3959330 light-hour | 10.5345454 light-hour | 10.6731579 light-hour | 10.8117703 light-hour | 10.9503828 light-hour | 11.0889952 light-hour | 11.2276076 light-hour | 11.3662201 light-hour | 11.5048325 light-hour | 11.6434450 light-hour | 11.7820574 light-hour | 11.9206698 light-hour | 12.0592823 light-hour | 12.1978947 light-hour | 12.3365072 light-hour | 12.4751196 light-hour | 12.6137320 light-hour | 12.7523445 light-hour | 12.8909569 light-hour | 13.0295694 light-hour | 13.1681818 light-hour | 13.3067942 light-hour | 13.4454067 light-hour | 13.5840191 light-hour | 13.7226316 light-hour | 13.8612440 light-hour |
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-hours | astronomical units | light-hours |
|---|---|---|---|
| 1 | ≡ 0.13861243995449 | 4 | ≡ 0.55444975981795 |
| 1.5 | ≡ 0.20791865993173 | 4.5 | ≡ 0.6237559797952 |
| 2 | ≡ 0.27722487990898 | 5 | ≡ 0.69306219977244 |
| 2.5 | ≡ 0.34653109988622 | 5.5 | ≡ 0.76236841974968 |
| 3 | ≡ 0.41583731986346 | 6 | ≡ 0.83167463972693 |
The light-hour is a unit of length useful in astronomy, telecommunications and relativistic physics. It is defined as the distance that light travels in free space in onehour, and is equal to exactly 1.0792528488×1012 metres.
| Name of unit | Symbol | Definition | Relation to SI units | Unit System |
|---|---|---|---|---|
| light-hour | ≡ 60 light-minutes | ≡ 1.0792528488×1012 m | Science - Astronomy (Length) |
| light-hours | astronomical units | light-hours | astronomical units |
|---|---|---|---|
| 1 | ≡ 7.21435969476 | 4 | ≡ 28.85743877904 |
| 1.5 | ≡ 10.82153954214 | 4.5 | ≡ 32.46461862642 |
| 2 | ≡ 14.42871938952 | 5 | ≡ 36.0717984738 |
| 2.5 | ≡ 18.0358992369 | 5.5 | ≡ 39.67897832118 |
| 3 | ≡ 21.64307908428 | 6 | ≡ 43.28615816856 |
| astronomical units | light-hours |
|---|---|
| 1 | ≡ 0.1386124 |
| 7.2143597 | ≡ 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 …) |