The target of this paper is a discussion of the meaning of the Newtonian concept of a reference f... more The target of this paper is a discussion of the meaning of the Newtonian concept of a reference frame showing no rotation with respect to a set of distant celestial objects in the framework of general relativity. Because of the properties of Newtonian absolute space and time and the existence of global inertial reference systems in Newton's theory the theoretical
This paper represents a first attempt of embedding the Barycentric Celestial Reference System, th... more This paper represents a first attempt of embedding the Barycentric Celestial Reference System, the fundamental relativistic reference system to be used for the modeling of Gaia observations, into some cosmological background. The general Robertson-Walker metric is transformed into local coordinates where the cosmological effects are represented as tidal potentials. A version of a cosmological BCRS is then suggested to lowest
There are at least four unexplained anomalies connected with astrometric data. Perhaps the most d... more There are at least four unexplained anomalies connected with astrometric data. Perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. Next, a secular change in the astronomical unit AU is definitely a concern. It
The Twelfth Marcel Grossmann Meeting - On Recent Developments in Theoretical and Experimental General Relativity Astrophysics and Relativistic Field Theories - Proceedings of the MG12 Meeting on General Relativity, 2012
Proceedings of the International Astronomical Union, 2009
Relativistic modelling of rotational motion of extended bodies represents one of the most complic... more Relativistic modelling of rotational motion of extended bodies represents one of the most complicated problems of Applied Relativity. The relativistic reference systems of IAU (2000) give a suitable theoretical framework for such a modelling. Recent developments in the post-Newtonian theory of Earth rotation in the limit of rigidly rotating multipoles are reported below. All components of the theory are summarized and the results are demonstrated. The experience with the relativistic Earth rotation theory can be directly applied to model the rotational motion of other celestial bodies. The high-precision theories of rotation of the Moon, Mars and Mercury can be expected to be of interest in the near future.
The Eleventh Marcel Grossmann Meeting - On Recent Developments in Theoretical and Experimental General Relativity, Gravitation and Relativistic Field Theories - Proceedings of the MG11 Meeting on General Relativity, 2008
Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in... more Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in the twenty-first century M. Perryman; 2. Astrometric satellites L. Lindegren; 3. Ground-based opportunities for astrometry N. Zacharias; Part II. Relativistic Foundations of Astrometry and Celestial Mechanics: 4. Vectors in astrometry, an introduction L. Lindegren; 5. Relativistic principles of astrometry and celestial mechanics S. Klioner; 6. Celestial mechanics of the N-body problem S. Klioner; 7. Celestial coordinate systems and positions N. Capitaine and M. Stavinschi; 8. Fundamental algorithms for celestial coordinates and positions P. Wallace; Part III. Observing through the Atmosphere: 9. The Earth's atmosphere: refraction, turbulence, delays and limitations to astrometic precision W. van Altena and E. Fomalont; 10. Astrometry with ground-based diffraction-limited imaging A. Ghez; 11. Optical interferometry A. Glindermann; 12. Radio interferometry E. Fomalont; Part VI. From D...
Proceedings of the International Astronomical Union, 2009
Gaia is an ambitious space astrometry mission of ESA with a main objective to map the sky in astr... more Gaia is an ambitious space astrometry mission of ESA with a main objective to map the sky in astrometry and photometry down to a magnitude 20 by the end of the next decade. Given its extreme astrometric accuracy and the repeated observations over five years, the observation modelling is done in a fully relativistic framework and several tests of General
ABSTRACT The problem of measuring gravitomagnetic effects by means of lunar laser ranging (LLR) i... more ABSTRACT The problem of measuring gravitomagnetic effects by means of lunar laser ranging (LLR) is investigated. The relevant terms in the Einstein-Infeld-Hoffmann equations of motion in barycentric coordinates are parametrized by a parameter ηG, which is fitted along with other parameters to LLR data and not derived from postfit residuals as it was done by other authors. The physical relevance of ηG and its relation to the preferred frame parameter α1 are discussed. Finally, α1 is fitted to LLR data by choosing the Barycentric Celestial Reference System as preferred frame instead of the cosmic rest frame determined via the temperature anisotropy of the cosmic microwave background radiation.
A Division 1 Working Group on "Nomenclature for Fundamental Astronomy" (NFA) was formed... more A Division 1 Working Group on "Nomenclature for Fundamental Astronomy" (NFA) was formed at the 25th IAU GA in 2003 in order to provide proposals for new nomencla- ture associated with the implementation of the IAU 2000 Resolutions. This WG is also intended to make related educational efforts for addressing the issue to the large community of scien- tists. Five
Gaia is ESA's ambitious space astrometry mission with a foreseen launch date around mid-2013.... more Gaia is ESA's ambitious space astrometry mission with a foreseen launch date around mid-2013. Its main objective is to perform a stellar census of the 1000 million brightest objects in our galaxy from which an astrometric catalogue of micro-arcsec level accuracy will be constructed. The Astrometric Global Iterative Solution (AGIS) is the mathematical and numerical framework for creating the astrometric core solution for this catalogue. At past ADASS meetings we have presented the basic working principles of AGIS and the development status of its main constituents. This year we discuss plans for another key step to mature AGIS into an operational system: Global (G) parameters are those influenced by all observations of Gaia in a global sense (e.g. the fundamental parameters of the Parametrized Post-Newtonian (PPN) formalism). We outline a scheme that will allow us to define in a very flexible way at run time the list of G-parameters to solve for. The scheme resembles the Generic ...
Gaia is an ESA cornerstone mission set to revolutionise our understanding of the Milky Way. Gaia ... more Gaia is an ESA cornerstone mission set to revolutionise our understanding of the Milky Way. Gaia is scheduled for launch in 2013, and is designed to map over one billion stars with three instruments to collect astrometric, photometric and spectroscopic data on stars in the Milky Way and in galaxies belonging to the Local Group, distant galaxies, quasars and solar system objects. Gaia builds on the expertise established in Europe through the successful ESA Hipparcos mission. This contribution provides updated information on the Gaia mission and notes the science performance capability of the mission. The GREAT (Gaia Research for European Astronomy Training) research network, which is taking a role in promoting scientific networking of the community building awareness and readiness in advance of the Gaia launch, is discussed.
The IAU2000 Resolutions concerning relativity introduce two celestial reference systems a barycen... more The IAU2000 Resolutions concerning relativity introduce two celestial reference systems a barycentric one BCRS with coordinates (tx) and a geocentric one GCRS with coordinates (TX). The two sets of coordinates are related by 4-dimensional space-time transformations. So far the relations of the BCRS and GCRS with the ICRS and ITRS have NOT been discussed. This will be done here. It is argued that the ICRS is a special represen- tation of the BCRS and the ITRS-coordinates differ from the GCRS ones by a time dependent rotation of spatial coordinates plus possible scale factors. This implies that also the ICRS- and the ITRS- coordinates are related by a generalized Lorentz-transformation.
The target of this paper is a discussion of the meaning of the Newtonian concept of a reference f... more The target of this paper is a discussion of the meaning of the Newtonian concept of a reference frame showing no rotation with respect to a set of distant celestial objects in the framework of general relativity. Because of the properties of Newtonian absolute space and time and the existence of global inertial reference systems in Newton's theory the theoretical
This paper represents a first attempt of embedding the Barycentric Celestial Reference System, th... more This paper represents a first attempt of embedding the Barycentric Celestial Reference System, the fundamental relativistic reference system to be used for the modeling of Gaia observations, into some cosmological background. The general Robertson-Walker metric is transformed into local coordinates where the cosmological effects are represented as tidal potentials. A version of a cosmological BCRS is then suggested to lowest
There are at least four unexplained anomalies connected with astrometric data. Perhaps the most d... more There are at least four unexplained anomalies connected with astrometric data. Perhaps the most disturbing is the fact that when a spacecraft on a flyby trajectory approaches the Earth within 2000 km or less, it often experiences a change in total orbital energy per unit mass. Next, a secular change in the astronomical unit AU is definitely a concern. It
The Twelfth Marcel Grossmann Meeting - On Recent Developments in Theoretical and Experimental General Relativity Astrophysics and Relativistic Field Theories - Proceedings of the MG12 Meeting on General Relativity, 2012
Proceedings of the International Astronomical Union, 2009
Relativistic modelling of rotational motion of extended bodies represents one of the most complic... more Relativistic modelling of rotational motion of extended bodies represents one of the most complicated problems of Applied Relativity. The relativistic reference systems of IAU (2000) give a suitable theoretical framework for such a modelling. Recent developments in the post-Newtonian theory of Earth rotation in the limit of rigidly rotating multipoles are reported below. All components of the theory are summarized and the results are demonstrated. The experience with the relativistic Earth rotation theory can be directly applied to model the rotational motion of other celestial bodies. The high-precision theories of rotation of the Moon, Mars and Mercury can be expected to be of interest in the near future.
The Eleventh Marcel Grossmann Meeting - On Recent Developments in Theoretical and Experimental General Relativity, Gravitation and Relativistic Field Theories - Proceedings of the MG11 Meeting on General Relativity, 2008
Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in... more Part I. Astrometry in the Twenty-First Century: 1. Opportunities and challenges for astrometry in the twenty-first century M. Perryman; 2. Astrometric satellites L. Lindegren; 3. Ground-based opportunities for astrometry N. Zacharias; Part II. Relativistic Foundations of Astrometry and Celestial Mechanics: 4. Vectors in astrometry, an introduction L. Lindegren; 5. Relativistic principles of astrometry and celestial mechanics S. Klioner; 6. Celestial mechanics of the N-body problem S. Klioner; 7. Celestial coordinate systems and positions N. Capitaine and M. Stavinschi; 8. Fundamental algorithms for celestial coordinates and positions P. Wallace; Part III. Observing through the Atmosphere: 9. The Earth's atmosphere: refraction, turbulence, delays and limitations to astrometic precision W. van Altena and E. Fomalont; 10. Astrometry with ground-based diffraction-limited imaging A. Ghez; 11. Optical interferometry A. Glindermann; 12. Radio interferometry E. Fomalont; Part VI. From D...
Proceedings of the International Astronomical Union, 2009
Gaia is an ambitious space astrometry mission of ESA with a main objective to map the sky in astr... more Gaia is an ambitious space astrometry mission of ESA with a main objective to map the sky in astrometry and photometry down to a magnitude 20 by the end of the next decade. Given its extreme astrometric accuracy and the repeated observations over five years, the observation modelling is done in a fully relativistic framework and several tests of General
ABSTRACT The problem of measuring gravitomagnetic effects by means of lunar laser ranging (LLR) i... more ABSTRACT The problem of measuring gravitomagnetic effects by means of lunar laser ranging (LLR) is investigated. The relevant terms in the Einstein-Infeld-Hoffmann equations of motion in barycentric coordinates are parametrized by a parameter ηG, which is fitted along with other parameters to LLR data and not derived from postfit residuals as it was done by other authors. The physical relevance of ηG and its relation to the preferred frame parameter α1 are discussed. Finally, α1 is fitted to LLR data by choosing the Barycentric Celestial Reference System as preferred frame instead of the cosmic rest frame determined via the temperature anisotropy of the cosmic microwave background radiation.
A Division 1 Working Group on "Nomenclature for Fundamental Astronomy" (NFA) was formed... more A Division 1 Working Group on "Nomenclature for Fundamental Astronomy" (NFA) was formed at the 25th IAU GA in 2003 in order to provide proposals for new nomencla- ture associated with the implementation of the IAU 2000 Resolutions. This WG is also intended to make related educational efforts for addressing the issue to the large community of scien- tists. Five
Gaia is ESA's ambitious space astrometry mission with a foreseen launch date around mid-2013.... more Gaia is ESA's ambitious space astrometry mission with a foreseen launch date around mid-2013. Its main objective is to perform a stellar census of the 1000 million brightest objects in our galaxy from which an astrometric catalogue of micro-arcsec level accuracy will be constructed. The Astrometric Global Iterative Solution (AGIS) is the mathematical and numerical framework for creating the astrometric core solution for this catalogue. At past ADASS meetings we have presented the basic working principles of AGIS and the development status of its main constituents. This year we discuss plans for another key step to mature AGIS into an operational system: Global (G) parameters are those influenced by all observations of Gaia in a global sense (e.g. the fundamental parameters of the Parametrized Post-Newtonian (PPN) formalism). We outline a scheme that will allow us to define in a very flexible way at run time the list of G-parameters to solve for. The scheme resembles the Generic ...
Gaia is an ESA cornerstone mission set to revolutionise our understanding of the Milky Way. Gaia ... more Gaia is an ESA cornerstone mission set to revolutionise our understanding of the Milky Way. Gaia is scheduled for launch in 2013, and is designed to map over one billion stars with three instruments to collect astrometric, photometric and spectroscopic data on stars in the Milky Way and in galaxies belonging to the Local Group, distant galaxies, quasars and solar system objects. Gaia builds on the expertise established in Europe through the successful ESA Hipparcos mission. This contribution provides updated information on the Gaia mission and notes the science performance capability of the mission. The GREAT (Gaia Research for European Astronomy Training) research network, which is taking a role in promoting scientific networking of the community building awareness and readiness in advance of the Gaia launch, is discussed.
The IAU2000 Resolutions concerning relativity introduce two celestial reference systems a barycen... more The IAU2000 Resolutions concerning relativity introduce two celestial reference systems a barycentric one BCRS with coordinates (tx) and a geocentric one GCRS with coordinates (TX). The two sets of coordinates are related by 4-dimensional space-time transformations. So far the relations of the BCRS and GCRS with the ICRS and ITRS have NOT been discussed. This will be done here. It is argued that the ICRS is a special represen- tation of the BCRS and the ITRS-coordinates differ from the GCRS ones by a time dependent rotation of spatial coordinates plus possible scale factors. This implies that also the ICRS- and the ITRS- coordinates are related by a generalized Lorentz-transformation.
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Papers by Sergei Klioner