Originally named S/2005 S1.
 
Daphnis is about 6 to 8 kilometers in diameter, and orbits the planet
in the Keeler Gap within the A ring.
 
Its discovery was announced by Carolyn Porco and the Cassini Imaging
Science Team on May 6, 2005, in six images taken by the Cassini probe
over 16 min on May 1 from a time-lapse sequence of 0.180 second
narrow-angle-camera exposures of the outer edge of the A ring. It was
subsequently found in 32 low-phase images taken of the F ring on
April 13 (spanning 18 min) and again in two high-resolution (3.54
km/pixel) low-phase images taken on May 2, when its 7 km disk was
resolved. It had previously been inferred from gravitational ripples
observed on the outer edge of the Keeler gap. This moon seems to make
waves inside the ring.
 
The inclination and eccentricity of Daphnis' orbit are very close to
zero, and are not distinguishable from it with present data. Daphnis
has an estimated albedo of 50%.