Relativistic effects and dark matter in the Solar system from observations of planets and spacecraft

摘要

The high precision of the latest version of the planetary ephemeris EPM2011enables one to explore more accurately a variety of small effects in the solarsystem. The processing of about 678 thousand of position observations ofplanets and spacecrafts for 1913--2011 with the predominance of modern radarmeasurements resulted in improving the PPN parameters, dynamic oblateness ofthe Sun, secular variation of the heliocentric gravitational constant$GM_{\odot}$, and variation range of the gravitational constant $G$. Thisprocessing made it possible to estimate the potential additional gravitationalinfluence of dark matter on the motion of the solar system bodies. The densityof dark matter ${\rho}_{dm}$, if any, turned out to be substantially below theaccuracy achieved by the present determination of such parameters. At thedistance of the orbit of Saturn the density ${\rho}_{dm}$ is estimated to beunder $1.1\cdot10^{-20}$ g/cm$^3$, and the mass of dark matter in the areainside the orbit of Saturn is less than $7.9\cdot10^{-11}$ M$_{\odot}$ eventaking into account its possible tendency to concentrate in the center.