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S/2004 S 3

Discovery image of S/2004 S 3
Discovery
Discovered by	CICLOPS Team
Discovery date	June 21, 2004
Orbital characteristics
Semi-major axis	140,100–140,600 km
Eccentricity	< 0.002
Orbital period (sidereal)	0.62 d
Inclination	close to zero
Satellite of	Saturn
Group	F Ring
Physical characteristics
Mean radius	~2 km
Synodic rotation period	probably synchronous
Axial tilt	unknown
Albedo	unknown

S/2004 S 3 is the provisional designation of an object seen orbiting Saturn just beyond the outer strand of the F ring on June 21, 2004. It was discovered by the Cassini Imaging Science Team Archived 2011-05-20 at the Wayback Machine in images taken by the Cassini–Huygens probe on June 21, 2004 and announced on September 9, 2004.

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 November 15, 2004 failed to recover the object. The sequence should have been easily capable of detecting a moon of similar size, suggesting it to simply be a transient clump. An approximate linkage could be made of S/2004 S 3 to S/2004 S 4, and matched to two other detected clumps on other dates, but considering its non-detection in November, their relation is probably coincidental.

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.

References

Explanatory

1. Based on above semimajor axis range, and Spitale Jacobson et al. 2006

Citations

1. CICLOPS Team.
2. ^ Spitale Jacobson et al. 2006.
3. IAUC 8432.
4. ^ Martinez, Ormrod & Finn 2004.
5. ^ IAUC 8401.

Sources

• "Cassini Imaging Science Team". Cassini Imaging Central Laboratory for OPerationS. Archived from the original on 2011-05-20. Retrieved 2012-01-01.
• Green, Daniel W. E. (September 9, 2004). "S/2004 S 3, S/2004 S 4, and R/2004 S 1" (discovery). IAU Circular. 8401: 1. Bibcode:2004IAUC.8401....1P. Retrieved 2012-01-01.
• Green, Daniel W. E. (November 8, 2004). "Satellites and Rings of Saturn". IAU Circular. 8432. Retrieved 2012-01-01. (claiming recovery of S/2004 S 3 on October 17, 2004 in conflict with the later Spitale Jacobson et al. 2006)
• Martinez, Carolina; Ormrod, Gill; Finn, Heidi (September 9, 2004). "Cassini Discovers Ring and One, Possibly Two, Objects at Saturn". jpl.nasa.gov. NASA Jet Propulsion Laboratory. Archived from the original on 2006-10-21. Retrieved 2012-01-01.
• Spitale, J. N.; Jacobson, R. A.; Porco, C. C.; Owen, W. M. Jr. (2006). "The orbits of Saturn's small satellites derived from combined historic and Cassini imaging observations". The Astronomical Journal. 132 (2): 692–710. Bibcode:2006AJ....132..692S. doi:10.1086/505206. S2CID 26603974.

External links

• Cassini–Huygens press release about discoveries around the F ring in 2004 at the Wayback Machine (archived 2004-10-16)
• Cassini–Huygens Multimedia: The Clump/Moon Mystery September 5, 2005 at the Library of Congress Web Archives (archived 2009-04-25) – images of the clumps and/or moons seen around the F ring by Cassini cameras

• Moons of Saturn
• Astronomical objects discovered in 2004