Equals 1/60 of 1/60 of a degree, written as ” in the degree-minutes-seconds format (xº x’ x”). Or, 1/60 of an arcminute, which is 1/60 of a degree. It is a unit of measure used for distances and finding objects in the sky. For instance, the apparent diameter of Jupiter is roughly 45 arcseconds.
- also refered to as ‘second’
See my article on measuring object in the sky using your hand.