Confirming Einstein's most fortunate thought(Nanowerk News) An international research team INCLUDING astronomers from the Max Planck Institute for Radio Astronomy in Bonn determined with extremely high precision that gravity causes neutron stars and white dwarf stars to fall with equal accelerations. They did this by precisely tracking the motion of pulsar PSR J0337+1715, a neutron star that is a member of an unusual triple star system.Their findings (Astronomy & Astrophysics, "An improved test of the strong equivalence principle with the pulsar in a triple star system") – achieved by a new rigorous method and a combination of radio telescope data with latest insight from gravitational wave detectors – provide the strongest test EVER of one of the most fundamental predictions of general relativity: that gravity attracts all objects with the same acceleration, without regard for their composition, density or the strength of their own gravitational field.PSR J0337+1715: An illustration of the triple millisecond pulsar with its two white dwarf companionsPSR J0337+1715: An illustration of the triple millisecond pulsar with its two white dwarf companions. The green mesh illustrates the curvature of space-time caused by the different masses. Size and distances of the three components are not to scale. (Image: Michael Kramer/MPIfR)Pulsar PSR J0337+1715, located in the constellation Taurus, is a neutron star of 1.44 solar masses, showing regular radio pulses as it rotates 366 times per second around its own axis. It is a member of an unusual triple star system, in mutual interaction with two other stars, both of which are white dwarfs.A white dwarf is already quite exotic - a star typically the size of the Earth with a density of many hundred kilograms per cubic centimeter at its center. Compared to white dwarfs a neutron star is TRULY extreme, having more mass than the Sun squashed into a diameter of just over 20 kilometers and by this reaching densities of more than a billion tons within the volume of a sugar cube.A research team, LED by Guillaume Voisin (Jodrell Bank Centre for Astrophysics/UK and Observatoire de Paris), including Paulo Freire, Norbert Wex and Michael Kramer of the Max Planck Institute for Radio Astronomy, and astronomers from several institutions in France, used the Nançay radio telescope, located in the Sologne REGION of France, to