Positions for the outer planets and many of their satellites. V. FASTT observations taken in 2000-2001

Authors
Citation
Rc. Stone, Positions for the outer planets and many of their satellites. V. FASTT observations taken in 2000-2001, ASTRONOM J, 122(5), 2001, pp. 2723-2733
Citations number
15
Categorie Soggetti
Space Sciences
Journal title
ASTRONOMICAL JOURNAL
ISSN journal
00046256 → ACNP
Volume
122
Issue
5
Year of publication
2001
Pages
2723 - 2733
Database
ISI
SICI code
0004-6256(200111)122:5<2723:PFTOPA>2.0.ZU;2-L
Abstract
As part of an ongoing observing program with the Flagstaff Astrometric Scan ning Transit Telescope (FASTT), this paper presents 1084 new equatorial pos itions 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 de termined using differential reductions with reference stars taken from eith er the ACT or Tycho-2 star catalog. An improvement in systematic accuracy w as made by introducing a correction for small focal-plane errors, and the o verall accuracy of FASTT observations has been improved as a result. When n ew and old FASTT positions are compared with modern Jet Propulsion Laborato ry (JPL) ephemerides, there is, in general, good agreement between FASTT po sitions and theory, wherein mean differences in each coordinate are smaller than 0."03 for the planets, and the agreement is usually better than 0."07 for the planetary satellites. In particular, the new JPL ephemerides for o uter 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 (>0."1) with respect to their pre dicted positions.