S/2004 S 3 is an unconfirmed moon of Saturn, seen orbiting just beyond the outer strand of the F ring on June 21, 2004. It was discovered by the 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.

Animated sequence of S/2004 S 3 discovery images by Cassini on June 21, 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.

Explanatory

Citations

Sources

  • . Cassini Imaging Central Laboratory for OPerationS. Archived from on 2011-05-20.
  • Green, Daniel W. E. (September 9, 2004). (discovery). IAU Circular (8401): 1. Bibcode:.
  • Green, Daniel W. E. (November 8, 2004). . IAU Circular (8432). (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). . jpl.nasa.gov. NASA Jet Propulsion Laboratory. Archived from on 2006-10-21.
  • Spitale, J. N.; Jacobson, R. A.; Porco, C. C.; Owen, W. M. Jr. (2006). . The Astronomical Journal. 132 (2): 692–710. Bibcode:. doi:. S2CID .

External links

  • at the Wayback Machine (archived 2004-10-16)
  • 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