Astroparticle Physics

16 Glossary 301The antiparticle of a quark.The point of greatest separation of two stars as in a binary star orbit.The point in the orbit of a planet, which is farthest from the Sun.The point in the orbit of an Earth satellite, which is farthest fromEarth.The brightness of a star as it appears to the observer. It is measuredin units of magnitude. See magnitude.Considerations on the formation and evolution of life in universeswith different fundamental parameters (different physical laws,quark masses, etc.)The average distance from Earth to Sun. 1 AU ≈ 149 597 870 km.At large momenta quarks will be eventually deconfined and becomeasymptotically free.The mass of a neutral atom or a nuclide. The atomic weight of anatom is the weight of the atom based on the scale where the massof the carbon-12 nucleus is equal to 12. For natural elements withmore than one isotope, the atomic weight is the weighted averagefor the mixture of isotopes.The number of protons in the nucleus.The northern (aurora borealis) or southern (aurora australis) lightsare bright emissions of atoms and molecules in the polar upperatmosphere around the south and north geomagnetic poles. Theaurora is associated with luminous processes caused by energeticsolar cosmic-ray particles incident on the upper atmosphere of theEarth.Advanced X-ray Astrophysics Facility; now named Chandra.Hypothetical pseudoscalar particle, which was introduced as quantumof a field to explain the non-observation of CP violation instrong interactions.See cosmic background radiation.Formation of baryons out of the primordial quark soup in the veryearly universe.antiquarkapastronaphelionapogeeapparent magnitudeastrobiologyastronomical unit (AU)asymptotic freedomatomic massatomic numberauroraAXAFaxionBbackground radiationbaryogenesis