Planetary Satellite Observations in the V3 Working Database





Previous detections and non-detections of the moons of Jupiter and Uranus and Neptune were reported shortly after it was discovered that these planets had been observed during V2 processing. There remained the possibility that more observations of not only Jupiter's moons, but also those belonging to Mars and Saturn existed in the database, since as was seen for several of Jupiter's moons, the outermost ones can be found in tiles that do not include the planet. Mars and Saturn were not covered by the survey, but perhaps some of their moons were. Uranus, Neptune and Pluto are distant enough that all of their satellites would appear in the same tiles as the planets (the moons of Mars are also never more than a few Mars-radii away, but I found this out after searching for them).

To search for moons, I generated ephemerides using JPL's Horizons software for all named moons of Mars, Jupiter and Saturn on all nights of 2MASS operations. I uploaded these tables in Gator and did cone searches with a 60-arcsec radius against the V3 point source working database. This radius was chosen to ensure that at least one field object would be detected near the predicted position of the moon (which might not be detected). The resulting tables were then searched for matches between the ephemerides and observation dates. The findings were as follows:

Mars
No observations of Phobos or Deimos. The closest we came to getting Mars was on 990420s while scanning about 2.6 degrees away.

Jupiter
No further observations of any moons, although Pasiphae was only one tile away on 981011s.

Saturn
No observations of any moons. The closest we came to getting Saturn was on 991222n while scanning about 1 degree away.

Performing a search in the V3 point source list on the positions of the detected moons listed in the above web pages gives this table (no filtering) and this table (catalog selection criteria). Note that Uranus was scanned twice (the webpage above only lists the 980607s observation), and that on 980607s it appeared in two adjacent scans. Using the catalog selection criteria drops a spurious K-only detection of Uranus 1.6 arcsec away from the other detections, a glint-contaminated detection of Miranda, an H-only detection of Oberon, and a 3-band detection of Umbriel which does not have anything obviously amiss. Note also that some of the V2-detected moons of Jupiter are in scans that were not run in V3 processing.

I propose that these moon detections be flagged as part of the final catalog generation. This is an operation that needs to be discussed among those more familiar with DB operations than I. Some combination of setting mp_flag to 1, adding an entry in the mp catalog, adding a an entry for mp_key, and adding a name would seem to be necessary. At present I do not know if just providing names of the moons would be enough to identify them. Are there asteroids with some of the same names as these moons? I'd think the IAU would be smarter than that, but maybe to be on the safe side, something like appending the name with -J for Jupiter etc. would be a good idea.


B. Nelson - IPAC
Last updated 15 March 2002