S/2004 S 3
Discovery image of S/2004 S 3
|Discovered by||Carl Murray|
Cassini Imaging Science Team
|Discovered on||21 June, 2004|
|Semimajor axis||140,100 − 140,600 km|
|Eccentricity||< 0.002 |
|Orbital period||0.62 d|
|Inclination||close to zero|
|Is a satellite of||Saturn|
|Mean diameter||3–5 km|
|Rotation period||probably synchronous|
S/2004 S 3 is the designation of an object seen orbiting Saturn just beyond the farther part of the F ring on 21 June, 2004. It was first seen by Carl Murray of the Cassini Imaging Science Team Archived 2011-05-20 at the Wayback Machine in pictures taken by the Cassini-Huygens probe on June 21, 2004, and announced on September 9, 2004.
Even though later astronomers tried to find it again, it has not been reliably seen since. Notably, an imaging sequence covering an entire orbital period at 4 km resolution taken on 15 November, 2004 failed to find the object. This suggests that it was a clump of material that had disappeared by that time.
Another object, S/2004 S 4, was seen nearby 5 hours later, but this time just inside the F Ring. Because of the different location of the second object, it 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 bit different inclination to the F ring, thereby not actually passing through the ring material even though it was 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 farther edge of Saturn's F ring.
References[change | change source]
- ↑ 1.0 1.1 Spitale, J. N.; et al. (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.
- ↑ 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 | display-authors = etal)
- ↑ 3.0 3.1 Martinez, C; Ormrod, G; and Finn, H.; Cassini Discovers Ring and One, Possibly Two, Objects at Saturn Archived 2006-10-21 at the Wayback Machine JPL news release (September 9 2004)
- ↑ Based on above semimajor axis range, and Spitale | display-authors = etal (2006)
- ↑ 5.0 5.1 IAUC 8401: S/2004 S 3, S/2004 S 4, and R/2004 S 1 2004 September 9 (discovery)
Other websites[change | change source]
- Cassini-Huygens press release about discoveries around the F ring in 2004 Archived 2004-10-16 at the Wayback Machine
- 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)