S/2004 S 3

'S/2004 S 3'

S2004 S 3 - PIA06115.png Discovery image of S/2004 S 3
Discovery
Discovered by	Carl Murray / Cassini Imaging Science Team
Discovered on	21 June, 2004
Orbital characteristics
Semimajor axis	140,100 − 140,600 km[1][2][3]
Eccentricity	< 0.002 [4]
Orbital period	0.62 d
Inclination	close to zero
Is a satellite of	Saturn
Physical characteristics
Mean diameter	3-5 km
Rotation period	probably synchronous
Axial tilt	unknown
Albedo	unknown
Atmosphere	none

'S/2004 S 3' is the provisional designation of an object seen orbiting Saturn just beyond the outer strand of the F ring on 21 June, 2004. It was first seen by Carl Murray of the Cassini Imaging Science Team in images taken by the Cassini-Huygens probe on June 21, 2004, and announced on September 9, 2004.^[5]
Despite later attempts to recover it, it has not been reliably sighted since. Notably, an imaging sequence covering an entire orbital period at 4 km resolution taken on 15 November, 2004 failed to recover the object. This suggests that it was a temporary clump of material that had disappeared by that time.
Another object, S/2004 S 4, was sighted nearby 5 hours later, but this time just ''inside'' the F Ring. Because of the differing localisation the second object was given a fresh designation, although their interpretation as a single object on a F-ring crossing orbit is also possible. Such an object might also be orbiting at a slightly different inclination to the F ring, thereby not actually passing through the ring material despite being seen both radially inward and outward of it.
If a solid object after all, S/2004 S 3 would be 3−5 km in diameter based on brightness, and might be a shepherd satellite for the outer edge of Saturn's F ring.

Contents

References

External links

References

1. ''The orbits of Saturn's small satellites derived from combined historic and ''Cassini'' imaging observations'', Spitale, J. N.; ''et al.'', , , The Astronomical Journal, 2006
2. IAUC 8432: ''Satellites and Rings of Saturn'' 2004 November 8 (claiming recovery of S/2004 S 3 on 17 October, 2004, in conflict with the later (2006) Spitale ''et al.'')
3. Martinez, C; Ormrod, G; and Finn, H.; ''Cassini Discovers Ring and One, Possibly Two, Objects at Saturn'' JPL news release (September 9 2004)
4. Based on above semimajor axis range, and Spitale ''et al.'' (2006)
5. IAUC 8401: ''S/2004 S 3, S/2004 S 4, and R/2004 S 1'' 2004 September 9 (discovery)

External links

★ Cassini-Huygens press release about discoveries around the F ring in 2004

★ Cassini-Huygens Multimedia: ''The Clump/Moon Mystery'' September 5, 2005 (images of the clumps and/or moons seen around the F ring by Cassini cameras)


''... | S/2004 S 4 | 'S/2004 S 3' | Pandora | ...''