CCD POSITIONS FOR THE OUTER PLANETS IN 1995 DETERMINED IN THE EXTRAGALACTIC REFERENCE FRAME

This paper presents positions for the planets Uranus, Neptune, and Plu to in 1995 determined in the extragalactic reference system with the F lagstaff CCD transit telescope (Stone et al. 1996, AJ, 111, 1721). In this paper, these positions are compared with the recent DE403 planeta ry ephemerides discussed in Standish et al. [1995, JPL IOM 314.10-127 (DE403).] There is excellent agreement between the observed and predic ted positions for Uranus and Neptune, wherein no evidence for systemat ic errors is found, and the mean (Observed-DE403) differences in posit ion are small (less than or equal to 0.06 arcsec in magnitude) and not significantly larger than their formal errors. The scatter in the res iduals for these planets is sigma similar to +/- 0.24 arcsec in both c oordinates, which can be explained by observational errors. For Pluto, the agreement is very good, but there is marginal evidence for an off set (Observed-DE403) in declination amounting to 0.13 +/- 0.03 (s.e.) arcsec. This possibility is based on only 22 observations, and clearly , future observations are needed for clarification. The scatter in the Pluto residuals is sigma similar to +/- 0.15 arcsec in both coordinat es, which is very small when compared with other Pluto observations. ( C) 1996 American Astronomical Society.