Astron. Astrophys. Suppl. Ser. 142, 81-84

CCD observations of Phoebe^,

C.H. Veiga - R. Vieira Martins - A.H. Andrei

Observatório Nacional, Rua Gal. José Cristino 77, 20921-400 Rio de Janeiro, Brazil
e-mail: cave@on.br or rvm@on.br

Received July 13; accepted November 19, 1999

Abstract:

Astromeric CCD positions of the Saturnian satellite Phoebe obtained from 60 frames taken in 10 nights are presented. The observations were distributed between 5 missions in the years 1995 to 1997. For the astrometric calibration the USNO-A2.0 Catalogue is used. All positions are compared with those calculated by Jacobson (1998a) and Bec-Borsenberger & Rocher (1982). The residuals have mean and standard deviation smaller than 0 $\hbox{$.\!\!^{\prime\prime}$ }$5, in the x and y directions. The distribution of residuals is suggestive of the need of an improvement for the orbit calculations.

Key words: astrometry -- planets and satellites -- Saturn