Full name: arcsecond
Plural form: arcseconds
Symbol: sec
Category type: angle
Scale factor: 4.8481368110954E-6
The SI derived unit for angle is the radian.
1 radian is equal to 206264.8062471 arcsecond.
Valid units must be of the angle type.
You can use this form to select from known units:
A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 (approximately 7.7×10-7) of a circle. It is the angular diameter of an object of 1 unit diameter at a distance of 360×60×60/(2pi) (approximately 206,265 units), such as (approximately) 1 cm at 2.1 km, or, directly from the definition, 1 astronomical unit at 1 parsec.