EDP Sciences
Free access
Volume 437, Number 3, July III 2005
Page(s) 1109 - 1113
Section Planets and planetary systems
DOI http://dx.doi.org/10.1051/0004-6361:20052728

A&A 437, 1109-1113 (2005)
DOI: 10.1051/0004-6361:20052728

Re-determination of Phoebe's orbit

K. X. Shen1, 2, D. Harper3, R. C. Qiao1, 2, G. Dourneau4 and J. R. Liu1, 2

1  National Time Service Center, The Chinese Academy of Science, PO Box 18, Lintong, Shaanxi 710600, PR China
    e-mail: shenkx@ntsc.ac.cn
2  United Laboratory for Optical Astrometry, The Chinese Academy of Science, PR China
3  Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SA, UK
4  Observatoire Aquitain des Sciences de l'Univers, UMR 5804 Laboratoire d'Astrodynamique, d'Astrophysique et d'Aéronomie de Bordeaux (L3AB), 2 rue de l'Observatoire, 33270 Floirac, France

(Received 20 January 2005 / Accepted 10 March 2005)

In order to improve the orbit of Phoebe, the ninth satellite of the Saturnian system, 101 new observations were made by our research team in 2003, using a CCD detector of large size ( $2048\times2048$ pixels) mounted on the 1.56 m astrometric reflector at the Sheshan Station of Shanghai Astronomical Observatory. We fitted a numerical integration of its orbit to all of the collected Earth-based astrometric observations from 1904 to 2003, including the newest precise data sets from Qiao & Tang and from Peng et al. A new set of initial conditions of Phoebe has been obtained, leading to an improved orbit of this satellite.

Key words: gravitation -- ephemerides -- methods: numerical -- reference systems -- astrometry -- time

© ESO 2005