Astronomical units of measurement
18 units from this system across 4 categories, 1 of them historical or traditional.
Length
| Unit | Symbol | Value in meters |
|---|---|---|
| astronomical unit | au | 149,597,870,700 m |
| light-second | ls | 299,792,458 m |
| light-minute | lmin | 17,987,547,480 m |
| light-hour | lh | 1,079,252,848,800 m |
| light-year | ly | 9.460730473×10¹⁵ m |
| parsec | pc | 3.085677581×10¹⁶ m |
| megaparsec | Mpc | 3.085677581×10²² m |
Weight & Mass
| Unit | Symbol | Value in kilograms |
|---|---|---|
| Earth mass | M⊕ | ≈ 5.9722×10²⁴ kg |
| solar mass | M☉ | ≈ 1.98847×10³⁰ kg |
Time
| Unit | Symbol | Value in seconds |
|---|---|---|
| Julian year | a | 31,557,600 s |
| tropical year | yr (trop) | ≈ 31,556,925.22 s |
| sidereal year | yr (sid) | ≈ 31,558,149.76 s |
| synodic month | mo (syn) | ≈ 2,551,442.976 s |
| sidereal day | d (sid) | ≈ 86,164.0905 s |
| aeon | Gyr | 3.1556952×10¹⁶ s |
Angle
| Unit | Symbol | Value in turns |
|---|---|---|
| milliarcsecond | mas | 7.716049383×10⁻¹⁰ turn |
| zodiac sign | sign | 0.08333333333 turn |
| hour angle | h | 0.04166666667 turn |