P_constants (PcK) SPICE kernel file Orientation constants for Ganymede =================================================================== Author : Nicolas Rambaux 2013 June 12, 2013 August 14, 20 September 2013 Version description -------------------------------------------------------- This is a prototype PcK file for the ESPaCe project. The data are based on the Rambaux etal 2011 paper [1]. Notably, the layers are rigid and the amplitudes of the short-period librations are larger than in the non-rigid case. Sources -------------------------------------------------------- The sources for the constants listed in this file are: [1] Rambaux, N., Van Hoolst, T., Karatekin, O, 2011 'Librational response of Europa, Ganymede, and Callisto with an ocean for a non-Keplerian orbit', A&A 527, A118 (2011) DOI: 10.1051/0004-6361/201015304 Remark: The phases of the Figures are not correct. [2] Archinal, B.A., A'Hearn, M.F., Bowell, E., Conrad, A., Consolmagno, G.J., Courtin, R., Fukushima, T., Hestroffer, D., Hilton, J.L., Krasinsky, G.A., Neumann, G., Oberst, J., Seidelmann, P.K., Stooke, P., Tholen, D.J., Thomas, P.C., and Williams, I.P. "Report of the IAU Working Group on Cartographic Coordinates and Rotational Elements: 2011." Explanatory Notes -------------------------------------------------------- This file works exactly as the PCK file pck00010.tpc available at naif website. Here the updated values are for the variables: BODY5_NUT_PREC_ANGLES BODY503_POLE_RA BODY503_POLE_DEC BODY503_PM BODY503_NUT_PREC_RA BODY503_NUT_PREC_DEC BODY503_NUT_PREC_PM Caution : this SPK should not be used if you studied the other Galilean satellites. The amplitudes of the short period librations are 0.00489472 and -0.00352361 degrees. They are computed for a rigid Ganymede. The deformation will decrease these amplitudes by a large factor (it could be a factor two). A new PCK kernel that takes into account the deformation will be available soon. Body numbers and names ---------------------------------------------------------- Barycenters:  5 Jupiter barycenter Mass centers: 503 Ganymede 10 Sun Orientation Constants for the Sun and Planets -------------------------------------------------------- Old values: 15 Fourier terms BODY5_NUT_PREC_ANGLES = ( 73.32 91472.9 24.62 45137.2 283.90 4850.7 355.80 1191.3 119.90 262.1 229.80 64.3 352.25 2382.6 113.35 6070.0 146.64 182945.8 49.24 90274.4 99.360714 4850.4046 175.895369 1191.9605 300.323162 262.5475 114.012305 6070.2476 49.511251 64.3000 ) The updated file contains 20 terms where the last 6 columns come from [1]. The phases are modified because the Tables in [1] are at J1950 and here the results are for J2000. Current values: \begindata BODY5_NUT_PREC_ANGLES = ( 73.32 91472.9 24.62 45137.2 283.90 4850.7 355.80 1191.3 119.90 262.1 229.80 64.3 352.25 2382.6 113.35 6070.0 146.64 182945.8 49.24 90274.4 99.360714 4850.4046 175.895369 1191.9605 300.323162 262.5475 114.012305 6070.2476 49.511251 64.3000 199.85805 3034.456102737231 25.76364 27276.62127108764 97.74430 28429.71459012778 124.48704 27077.81207814968 268.61084 262235.6036702048 327.17771 1837584.999412145 ) \begintext Orientation constants for the satellites -------------------------------------------------------- Ganymede Old values: The RA and DEC are not changed BODY503_POLE_RA = ( 268.20 -0.009 0. ) BODY503_POLE_DEC = ( 64.57 0.003 0. ) BODY503_PM = ( 44.064 50.3176081 0. ) BODY503_LONG_AXIS = ( 0. ) BODY503_NUT_PREC_RA = ( 0. 0. 0. -0.037 0.431 0.091 ) BODY503_NUT_PREC_DEC = ( 0. 0. 0. -0.016 0.186 0.039 ) BODY503_NUT_PREC_PM = ( 0. 0. 0. 0.033 -0.389 -0.082 ) Current values: \begindata BODY503_POLE_RA = ( 268.20 -0.009 0. ) BODY503_POLE_DEC = ( 64.57 0.003 0. ) BODY503_PM = ( 44.064 50.3176081 0. ) BODY503_LONG_AXIS = ( 0. ) BODY503_NUT_PREC_RA = ( 0. 0. 0. -0.037 0.431 0.091 ) BODY503_NUT_PREC_DEC = ( 0. 0. 0. -0.016 0.186 0.039 ) BODY503_NUT_PREC_PM = ( 0. 0. 0. 0.0 -0.000 -0.000 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.013254 0.011382 0.0095228 0.0059362 0.00489472 -0.00352361) \begintext BODY503_NUT_PREC_PM = ( 0. 0. 0. 0.033 -0.389 -0.082 0. 0. 0. 0. 0. 0. 0. 0. 0. 0.013254 0.011382 0.0095228 0.0059362 0.00489472 -0.00352361)