=============================================================================== file 1999-2000_J1-4_6-8_stone.data.txt Contents: This file contains astrometric observations of the satellites of Jupiter J1, J2, J3, J4, J6, J7, J8 made with the Flagstaff Astrometric Transit Telescope (FASTT). J-1: 55 observations made from 1999 Aug. 16 to 2000 January 11 J-2: 61 observations made from 1999 Aug. 16 to 2000 January 13 J-3: 64 observations made from 1999 Aug. 16 to 2000 January 13 J-4: 70 observations made from 1999 Aug. 16 to 2000 January 13 J-6: 58 observations made from 1999 Aug. 16 to 2000 January 11 J-7: 37 observations made from 1999 July 4 to 2000 January 13 J-8: 38 observations made from 1999 Sept. 13 to 2000 January 8 References: These data are extracted from the ftp server of USNO and are documented in: Stone, R.C.: 2000, Positions for the outer planets and many of their satellites IV: FASTT observations taken in 1999-2000, Astron. J., 120, 2124-2130 Format: Planet/satellite data in NOFS standard format follows: J2000 coordinates (ICRS) with no correction for light time Column 1 ..... Planet ID 2 ..... Satellite ID 3- 5 ..... UT (yr,mon,day) 6- 8 ..... UTC (h,m,s) 9-11 ..... J2000 RA (h,m,s) 12-14 ..... J2000 Dec (d,m,s) 15 ..... Geocentric parallax in RA (arcsec) [geo - topo positions] 16 ..... Geocentric parallax in Dec (arcsec) [geo - topo positions] 17 ..... Observatory Code 18 ..... Type of Obs (topo/geoc) 19 ..... NOFS Telescope/Reference Catalog 20 ..... Proper Name Informations: The Flagstaff Astrometric Transit Telescope (FASTT) started a program in 1995 to determine accurate equatorial positions for the outer planets Uranus, Neptune, and Pluto in the extragalactic reference frame. These data were published in Stone, R.C. 1996, AJ, 781 and Stone, R.C. 1998, AJ, 166, 1461. Since then, these positions have been put on the IAU standard ICRF coordinate system. Starting in 1998, FASTT positions were and will continue to be determined directly in the ICRF using differential CCD reductions and ACT reference stars. The accuracy of FASTT positions has improved from about +/-0.2 (extragalactic) to +/-0.07 (ACT) arcsec. Also, starting in 1998, the FASTT observational program was expanded and now include the following satellites of Jupiter to Neptune: Jupiter: Io, Europa, Ganymede, Callisto, Himalia, Elara, Pasiphae Saturn: Tethys, Dione, Rhea, Titan, Hyperion, Iapetus, Phoebe Uranus: Titania, Oberon Neptune: Triton A total of 17 planetary satellites are now observed routinely with the FASTT as well as the planets Uranus, Neptune, and Pluto. Accurate equatorial positions are determined for all of these objects, and, in addition, equatorial positions for Jupiter, Saturn, Uranus, and Neptune can be determined from the barycentric motions of their satellites. A paper describing all the reductions (Stone, R.C. and Harris, F.H. 1999, AJ, 119, 1985) has been written and gives detailed information about the accuracies achieved and comparisons with modern JPL ephemerides. The accuracies range from +/-0.08 arcsec to +/-0.25 arcsec, depending on the S/N observed for each object. When compared with DE405 ephemerides, there is generally good agreement between FASTT planetary positions and orbital predictions. Much the same is true for the planetary satellites listed above with some exceptions. Enquires about the data should be addressed to: Ronald C. Stone Tel: 520-779-5132 U.S. Naval Observatory FAX: 520-774-3626 Flagstaff Station EMail: rcs@nofs.navy.mil P.O. Box 1149 Flagstaff, AZ 86002 USA ==============================================================================