Julian year a
About the Julian year
In astronomy the Julian year is exactly 365.25 days of 86,400 seconds, or 31,557,600 seconds. It is the year used to define the light-year and to express long time spans. It equals the average length of a year in the Julian calendar, which is where its name comes from.
Related Units
Second
sBase unit; caesium-133 frequency = 9,192,631,770 Hz exactly
The second is defined by taking the unperturbed ground-state hyperfine transition frequency of the caesium-133 atom to...
Hertz
Hz1 Hz = 1 s⁻¹
The hertz is one cycle or event per second and replaced the older expression cycles per second. It is named after...
Day
d1 d = 86,400 s (exact)
As a unit accepted for use with the SI, the day is exactly 86,400 seconds. The actual solar day varies slightly and the...
Astronomical unit
au149,597,870,700 m (exact)
The astronomical unit is roughly the mean distance from the Earth to the Sun. Since the IAU's 2012 Resolution B2 it is...