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Slava G. Turyshev

Publications and source records attributed to Slava G. Turyshev.

157 records · Page 9Linked to original sources
arXiv2002

Relativistic stellar aberration for the Space Interferometry Mission (2)

We address the issue of relativistic stellar aberration requirements for the Space Interferometry Mission (SIM). Motivated by the importance of this issue for SIM, we have considered a problem of relative astrometric observations of two stars separated by angle $θ$ on the sky with a single baseline interferometer. While a definitive answer on the stellar aberration issue may be obtained only in numerical simulations based on the accurate astrometric model of the instrument, one could still derive realistic conclusions by accounting for the main expected properties of SIM. In particular, we have analysied how the expected astrometric accuracy of determination of positions, parallaxes and proper motions will constrain the accuracy of the spaceraft navigation. We estimated the astrometric errors introduced by imperfect metrology (variations of the calibration term across the tile of interest), errors in the baseline length estimations, and those due to orbital motion of the spacecraft. We also estimate requirements on the data sampling rate necessary to apply on-board in order to correct for the stellar aberration. We have shown that the worst case observation scenario is realized for the motion of the spacecraft in the direction perpendicular to the tile. This case of motion will provide the most stringent requirement on the accuracy of knowledge of the velocity's magnitude. We discuss the implication of the results obtained for the future mission analysis.

gr-qc↗
arXiv2002

Relativistic stellar aberration for the Space Interferometry Mission: parallax analysis

This paper is a continuation of our previous analysis (i.e. Turyshev 2002a, 2002b) of the relativistic stellar aberration requirements for the Space Interferometry Mission (SIM). Here we have considered a problem of how the expected astrometric accuracy of parallax determination will constrain the accuracy of the spacecraft navigation. We show that effect of the spacecraft's navigational errors on the accuracy of parallax determination with SIM will be negligible. We discuss the implication of the results obtained for the future mission analysis.

gr-qc↗
arXiv2001

The Anomalous Trajectories of the Pioneer Spacecraft

Because of their unique designs, the Pioneer 10 and 11 spacecraft have provided the cleanest Doppler, deep-space navigation data. Analysis of this data can be interpreted as showing an anomalous acceleration of these craft directed towards the Sun of $a_P \sim 8 \times 10^{-8} {\rm cm/s}^2$. The background of this discovery and the significance of the result are discussed.

hep-ph↗
arXiv1999

The Apparent Anomalous, Weak, Long-Range Acceleration of Pioneer 10 and 11

Recently we reported that radio Doppler data generated by NASA's Deep Space Network (DSN) from the Pioneer 10 and 11 spacecraft indicate an apparent anomalous, constant, spacecraft acceleration with a magnitude $\sim 8.5\times 10^{-8}$ cm s$^{-2}$, directed towards the Sun (gr-qc/9808081). Analysis of similar Doppler and ranging data from the Galileo and Ulysses spacecraft yielded ambiguous results for the anomalous acceleration, but it was useful in that it ruled out the possibility of a systematic error in the DSN Doppler system that could easily have been mistaken as a spacecraft acceleration. Here we present some new results, including a critique suggestions that the anomalous acceleration could be caused by collimated thermal emission. Based partially on a further data for the Pioneer 10 orbit determination, the data now spans January 1987 to July 1998, our best estimate of the average Pioneer 10 acceleration directed towards the Sun is $\sim 7.5 \times 10^{-8}$ cm s$^{-2}$.

gr-qc↗
arXiv1998

Indication, from Pioneer 10/11, Galileo, and Ulysses Data, of an Apparent Anomalous, Weak, Long-Range Acceleration

Radio metric data from the Pioneer 10/11, Galileo, and Ulysses spacecraft indicate an apparent anomalous, constant, acceleration acting on the spacecraft with a magnitude $\sim 8.5\times 10^{-8}$ cm/s$^2$, directed towards the Sun. Two independent codes and physical strategies have been used to analyze the data. A number of potential causes have been ruled out. We discuss future kinematic tests and possible origins of the signal.

gr-qc↗
arXiv1996

Relativistic Navigation: A Theoretical Foundation

We present a theoretical foundation for relativistic astronomical measurements in curved space-time. In particular, we discuss a new iterative approach for describing the dynamics of an astronomical N-body system. To do this, we generalize the Fock-Chandrasekhar method of the weak-field and slow-motion approximation (WFSMA) and develop a theory of relativistic reference frames (RF) for a gravitationally bounded many-extended-body problem. In any proper RF constructed in the immediate vicinity of an arbitrary body, the N-body solutions of the gravitational field equations are presented as a sum of the Riemann-flat inertial space-time, the gravitational field generated by the body itself, the unperturbed solutions for each body in the system transformed to the coordinates of this proper RF, and the gravitational interaction term. We develop the basic concept of a general theory of the celestial RFs applicable to a wide class of metric theories of gravity with an arbitrary model of matter distribution. We apply the proposed method to general relativity. Bodies are described using a perfect fluid model; as such, they possess any number of internal mass and current multipole moments which explicitly characterize their internal structure. The obtained relativistic equations of motion contain an explicit information about the coupling of the bodies proper multiple moments to the surrounding gravitational field. We further generalize the proposed method and include two Eddington parameters $(γ,β)$. This generalized approach was used to derive the relativistic equations of satellite motion in the vicinity of the extended bodies. We discuss the possible future implementation of the proposed formalism in software codes developed for solar-system orbit determination.

gr-qc↗
arXiv1996

Relativistic Gravity Theory And Related Tests With A Mercury Orbiter Mission

Due to its relatively large eccentricity and proximity to the Sun, Mercury's orbital motion provides one of the best solar-system tests of relativistic gravity. We emphasize the number of feasible relativistic gravity tests that can be performed within the context of the parameterized weak field and slow motion approximation - a usefulframework for testing modern gravitational theories in the solar system. We discuss a new approximation method, which includes two Eddington parameters $(γ,β)$, proposed for construction of the relativistic equations of motion of extended bodies. Within the present accuracy of radio measurements, we discuss the generalized Fermi-normal-like proper reference frame which is defined in the immediate vicinity of the extended compact bodies. Based on the Hermean-centric equations of motion of the spacecraft around the planet Mercury, we suggest a new test of the Strong Equivalence Principle. The corresponding experiment could be performed with the future {\it Mercury Orbiter} mission scheduled by the European Space Agency ({\small ESA}) for launch between 2006 and 2016. We discuss other relativistic effects including the perihelion advance, redshift and geodetic precession of the orbiter's orbital plane about Mercury.

gr-qc↗
arXiv1995

Testing the Strong Equivalence Principle with Mars Ranging Data

The year 1996 will mark the initiation of a number of new space missions to the planet Mars from which we expect to obtain a rich set of data, including spacecraft radio tracking data. Anticipating these events, we have analyzed the feasibility of testing a violation of the strong equivalence principle (SEP) with Earth-Mars ranging. Using analytic and numerical methods, we have demonstrated that ranging data can provide a useful estimate of the SEP parameter $η$. Two estimates of the predicted accuracy are quoted, one based on conventional covariance analysis, and the other based on ``modified worst case'' analysis, which assumes that systematic errors dominate the experiment. If future Mars missions provide ranging measurements with an accuracy of $σ$ meters, after ten years of ranging the expected accuracy for the parameter $η$ will be of order $σ_η\approx (1-12)\times 10^{-4}σ$. In addition, these ranging measurements will provide a significantly improved determination of the mass of the Jupiter system, independent of the test of the {\small SEP} polarization effect.

astro-ph↗
arXiv1995

Are the singularities stable?

The spacetime singularities play a useful role in gravitational theories by distinguishing physical solutions from non-physical ones. The problem, we studying in this paper is: are these singularities stable? To answer this question, we have analyzed the general problem of stability of the family of the static spherically symmetric solutions of the standard Einstein-Maxwell model coupled to an extra free massless scalar field. We have obtained the equations for the axial and polar perturbations. The stability against axial perturbations has been proven.

hep-th↗
arXiv1995

The Solar Test of the Equivalence Principle

The Earth, Mars, Sun, Jupiter system allows for a sensitive test of the strong equivalence principle (SEP) which is qualitatively different from that provided by Lunar Laser Ranging. Using analytic and numerical methods we demonstrate that Earth-Mars ranging can provide a useful estimate of the SEP parameter $η$. Two estimates of the predicted accuracy are derived and quoted, one based on conventional covariance analysis, and another (called ``modified worst case'' analysis) which assumes that systematic errors dominate the experiment. If future Mars missions provide ranging measurements with an accuracy of $σ$ meters, after ten years of ranging the expected accuracy for the SEP parameter $η$ will be of order $(1-12)\times 10^{-4}σ$. These ranging measurements will also provide the most accurate determination of the mass of Jupiter, independent of the SEP effect test.

gr-qc↗
arXiv1995

Black holes with regular horizons in Maxwell-scalar gravity

A class of exact static spherically symmetric solutions of the Einstein-Maxwell gravity coupled to a massless scalar field has been obtained in harmonic coordinates of the Minkowski space-time. For each value of the coupling constant $a$, these solutions are characterized by a set of three parameters, the physical mass $μ_0$, the electric charge $Q_0$ and the scalar field parameter $k$. We have found that the solutions for both gravitational and electromagneticfields are not only affected by the scalar field, but also the non-trivial coupling with matter constrains the scalar field itself. In particular, we have found that the constant $k$ generically differs from $\pm 1/2$, falling into the interval $|k|\in [0, {1\over2}\sqrt{1+a^2} \hskip 2pt ]$. It takes these values only for black holes or in the case when a scalar field $ϕ$ is totally decoupled from the matter. Our results differ from those previously obtained in that the presence of arbitrary coupling constant $a$ gives an opportunity to rule out the non-physica horizons. In one of the special cases, the obtained solution corresponds to a charged dilatonic black hole with only one horizon $μ_+$ and hence for the Kaluza-Klein case. The most remarkable property of this result is that the metric, the scalar curvature, and both electromagnetic and scalar fields are all regular on this surface. Moreover, while studying the dilaton charge, we found that the inclusion of the scalar field in the theory result in a contraction of the horizon. The behavior of the scalar curvature was analyzed.

hep-th↗