J/A+A/355/398ivo://CDS.VizieR/J/A+A/355/398doi:10.26093/cds/vizier.33550398CDSCapitaine N.Guinot B.McCarthy D.D.2000-03-25T07:33:29Z2000-03-25T08:33:23ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frephemeridesearth-planetThe adoption of the International Celestial Reference System ICRS, and of the corresponding Frame, ICRF, by the 23rd General Assembly of the International Astronomical Union, calls for a redefinition of the departure point on the true equator. Several possibilities have been suggested. This paper considers the use of the non-rotating origin (Guinot, 1979, In: McCarthy D.D., Pilkington J.D. (eds.) Time and the Earth's Rotation. D. Reidel Pub. Co, p. 7). The ``Celestial Ephemeris Origin'' (CEO) is defined here as the non-rotating origin on the equator of the Celestial Ephemeris Pole (CEP). Developments valid at the microarcsecond, based on the best model for precession, nutation and pole offset at J2000.0 with respect to the pole of ICRF, are provided for computing the CEP coordinates and the position of the CEO. It is shown that an operational definition of UT1 based on the CEO leads to values which are insensitive at the microarcsecond level to future improvements of this model.2000A&A...355..398Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/355/398CatalogResearchIsServedByTAP VizieR generic servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/355/398https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/355/398http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/355/398https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/355/398https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/355/398http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/355/398GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapdefaultJ/A+A/355/398/table1aNumerical Development of the coordinates X(t), Y(t) of the Celestial Ephemeris Pole in the ICRS consistent with the IERS 1996 Conventions and the IERS Annual report for 1997 (unit {mu}as)i[1/269]+ Number iintprimaryindexedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.intlMean anomaly of the Moon coefficientintl'Mean anomaly of the Sun coefficientintFL - Omega (L: Mean longitude of the Moon) coefficientintDMean elongation from the Moon to the Sun coefficientintOmegaMean longitude of the ascending node of the Moon coefficientintPerPeriod of the nutationddoubleas0i(a_s,0_)_i_ coefficient (1)uarcsecintas1i(a_s,1_)_i_ coefficient (2)uarcsec/hyrintas2i(a_s,2_)_i_ coefficient (2)uarcsec.hyr**-2intac0i(a_c,0_)_i_ coefficientuarcsecintac1i(a_c,1_)_i_ coefficientuarcsec/hyrintac2i(a_c,2_)_i_ coefficientuarcsec.hyr**-2intbc0i(b_c,0_)_i_ coefficient (1)uarcsecintbc1i(b_c,1_)_i_ coefficient (2)uarcsec/hyrintbc2i(b_c,2_)_i_ coefficient (2)uarcsec.hyr**-2intbs0i(b_s,0_)_i_ coefficientuarcsecintbs1i(b_s,1_)_i_ coefficientuarcsec/hyrintbs2i(b_s,2_)_i_ coefficientuarcsec.hyr**-2intJ/A+A/355/398/table1bNumerical Development of the planetary nutations in the coordinates X(t), Y(t) of the CEP in the ICRS consistent with the IERS 1996 Conventions and the IERS Annual report for 1997 (unit {mu}as)recnoRecord number assigned by the VizieR team. Should Not be used for identification.inti[1/112]+ Number iintprimaryindexedlVeMean longitude of Venus coefficientintlEMean longitude of the Earth coefficientintlMaMean longitude of Mars coefficientintlJMean longitude of Jupiter coefficientintlSaMean longitude of Saturn coefficientintpaGeneral precession in longitude coefficientintDMean elongation from the Moon to the Sun coefficientintFL - Omega (L: Mean longitude of the Moon) coefficientintlMean anomaly of the Moon coefficientintOmegaMean longitude of the ascending node of the Moon coefficientintPerPeriod of the nutationddoubleas0i(a_s,0_)_i_ coefficientuarcsecintas1i(a_s,1_)_i_ coefficientuarcsec/hyrintas2i(a_s,2_)_i_ coefficientuarcsec.hyr**-2intac0i(a_c,0_)_i_ coefficientuarcsecintac1i(a_c,1_)_i_ coefficientuarcsec/hyrintac2i(a_c,2_)_i_ coefficientuarcsec.hyr**-2intbc0i(b_c,0_)_i_ coefficientuarcsecintbc1i(b_c,1_)_i_ coefficientuarcsec/hyrintbc2i(b_c,2_)_i_ coefficientuarcsec.hyr**-2intbs0i(b_s,0_)_i_ coefficientuarcsecintbs1i(b_s,1_)_i_ coefficientuarcsec/hyrintbs2i(b_s,2_)_i_ coefficientuarcsec.hyr**-2int