Spat (angular unit)

The spat (symbol sp^[1]), from the Latin spatium ("space"), is a unit of solid angle.^[2][3] One spat is equal to 4π steradians^[1][3] or approximately 41253 square degrees of solid angle (sequence A125560 in the OEIS).^[2] Thus 1 sp is the solid angle subtended by a complete sphere at its center.^[2]