Positions for the Outer Planets and Many of Their Satellites. V. FASTT Observations Taken in 2000-2001

摘要

As part of an ongoing observing program with the Flagstaff Astrometric Scanning Transit Telescope (FASTT), this paper presents 1084 new equatorial positions taken in 2000–2001 for the outer planets Uranus, Neptune, and Pluto, as well as for 17 satellites of Jupiter–Neptune. All the positions were determined using differential reductions with reference stars taken from either the ACT or Tycho-2 star catalog. An improvement in systematic accuracy was made by introducing a correction for small focal-plane errors, and the overall accuracy of FASTT observations has been improved as a result. When new and old FASTT positions are compared with modern Jet Propulsion Laboratory (JPL) ephemerides, there is, in general, good agreement between FASTT positions and theory, wherein mean differences in each coordinate are smaller than 003 for the planets, and the agreement is usually better than 007 for the planetary satellites. In particular, the new JPL ephemerides for outer satellites of Jupiter (Himalia, Pasiphae, and Elara) are significantly better than their older versions. Finally, Titania and Oberon, satellites of Uranus, continue to show large offsets (>01) with respect to their predicted positions.