Related by context. Frequent words. (Click for all words.) 54 magnetization 53 oscillations 51 angular momentum 50 amplitudes 49 periodicity 49 oscillation 48 gravitational 48 spectra 48 spacetime 48 electron spin 47 equinox 47 gravitation 46 dynamical 45 ellipse 45 aurora 44 vibrational 44 vortices 44 interstellar medium 44 solstice 44 orbits 44 conductance 44 spring equinox 44 photons 44 pulsar 44 starlight 43 cosmic ray 43 quasar 43 nucleation 43 scalar 43 curvature 43 annular 43 atoms 43 elliptical galaxies 43 surface roughness 43 diffraction 43 elliptical orbit 43 hysteresis 43 circular orbit 42 electrons 42 proton 42 quantum mechanical 42 heliosphere 42 electron 42 cyclic 42 magnetic fields 42 geometry 42 velocities 42 celestial 42 perturbation 42 magnetosphere 42 geomagnetic 42 magnetic 42 perturbations 42 luminosity 42 femtosecond 42 cosmic microwave background 42 deformation 42 celestial bodies 42 winter solstice 42 neutron star 42 neutrons 41 entropy 41 interstellar dust 41 logarithmic 41 refraction 41 dipole 41 parabola 41 perigee 41 corona 41 photon 41 interferometer 41 supernova explosion 41 orbital 40 nebula 40 atomic nuclei 40 counter clockwise 40 chemical reactions 40 radioactive decay 40 ferromagnetic 40 radii 40 amplitude 40 cosmic 40 geometrical 40 helix 40 crustal 40 gravitational waves 40 CMEs 40 neutron stars 40 supernova 40 rhythmical 40 particle 40 laser pulses 39 Winter Solstice 39 quasars 39 hydrogen atom 39 redshift 39 ions 39 reflectance 39 supernovae 39 spectroscopic 39 spiral galaxies