... NEUTRON STAR: A celestial body hypothesized to occur in a terminal stage of stellar evolution, essentially consisting of a super dense mass of neutrons and having a powerful gravitational attraction from which only neutrinos and high-energy photons can ...
... GREENWICH MERIDIAN: See: Prime Meridian . H . HELIUM (He): The second element in the periodic table, has 2 protons, 2 neutrons, and is a noble gas. ...
... X-ray Timing Explorer - NASA's X-ray Timing Explorer (XTE) was launched on 1995 December 30 and will spend the next few years observing X-rays from white dwarfs, neutron stars and black holes. ...
... Consists of protons and neutrons. AXIAL TILT: The angle between the axis of rotation of an object and a line perpendicular to its plane of orbit. ...
... Redshift is also an important tool to measure the velocity of gas of interstellar clouds, the rotation of galaxies, and the actions of accretion around neutron stars and black holes. ...