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[4] and announced on September 9, 2004.[5]
 Discovery image of S/2004 S 3 | |
| Discovery | |
|---|---|
| Discovered by | CICLOPS Team [1] |
| Discovery date | June 21, 2004 |
| Orbital characteristics [2][3][4] | |
| 140,100–140,600 km | |
| Eccentricity | < 0.002 [a] |
| 0.62 d | |
| Inclination | close to zero |
| Satellite of | Saturn |
| Group | F Ring |
| Physical characteristics | |
| ~2 km | |
| probably synchronous | |
| unknown | |
| Albedo | unknown |
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.[2]
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.[5] 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
editExplanatory
- ^ Based on above semimajor axis range, and Spitale Jacobson et al. 2006
Citations
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
edit- 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