Astrophysics

state of matter consisting of ionized gas

thumb|Early 1900s comparison of elemental, solar, and stellar spectra

stars powered by fusion of hydrogen in shell with an inactive core of helium

electromagnetic radiation as a remnant from an early stage of the universe in Big Bang cosmology

hypothetical region of spacetime that serves as the opposite of a black hole

branch of cosmology which studies mathematical models of the universe

maximum mass of a stable white dwarf star, approximately 1.4 solar masses

thumb|alt=Diagram|Diagram illustrating the creation of new elements by the Nucleosynthesis is the process that creates new atomic nuclei from nucleons (protonsand neutrons) and nuclei. According to current theories, the first nuclei were formed a fewminutes after the through nuclear reactions in a process called BigBang nucleosynthesis. After about 20minutes, the universe had expanded and cooled to a point at which these collisions among nucleons ended, so only the fastest and simplest reactions occurred, leaving our universe containing hydrogen and helium, traces of other elements, such as l

scattering of a photon off of a charged particle

the determination of light intensities of astronomical bodies, including stars

space telescope for gamma-ray astronomy launched in 2008

thumb|Meteorites are often studied as part of cosmochemistry.

thumb|Different oscillation modes have different sensitivities to the structure of a star. By observing multiple modes, one can therefore partially infer a star's internal structure. Asteroseismology is the study of oscillations in stars. Stars have many resonant modes and frequencies, and the path of sound waves passing through a star depends on the local speed of sound, which in turn depends on local temperature and chemical composition. Because the resulting oscillation modes are sensitive to different parts of the star, they inform astronomers about the internal structure of the star, whic

alternative explanation of the non-Newtonian rotation of galaxies

upper bound to the mass of cold, nonrotating neutron stars

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type of nozzle

any of several measures of the occurrence of different chemical elements

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The slow neutron-capture process, or '''s-process', is a series of reactions in nuclear astrophysics that occur in stars, particularly asymptotic giant branch stars. The s''-process is responsible for the creation (nucleosynthesis) of approximately half the atomic nuclei heavier than iron.

geochemical classification grouping the chemical elements according to their preferred host phases

luminosity-temperature relationship obeyed by infant stars

thumb|upright=1.5|This image presents various wavelengths of light produced by the Sun.

thumb|Phases of the reionization In the fields of Big Bang theory and cosmology, reionization is the process that caused electrically neutral atoms in the primordial universe to reionize after the lapse of the "dark ages". Detecting and studying the reionization process is challenging but multiple avenues have been pursued. This reionization was driven by the formation of the first stars and galaxies.

type of astronomy involving observation of gravitational waves

structure in the lower corona and transition region of the Sun

apparent faster-than-light motion of distant astronomical objects

branch of astrophysics

type of variable star

production of the elements in a supernova explosion

purported correlation of the cosmic microwave background with the Earth’s ecliptic

celestial body that is not a monolith

negative ion of hydrogen

astronomical magnitude measured with photographic plate

thumb|Mt. St Helens eruption plume on 22 July 1980, showing ejecta in the form of pyroclastic material (ash)

star in the constellation Centaurus

dimensionless form of Poisson's equation for the gravitational potential of a Newtonian self-gravitating, spherically symmetric, polytropic fluid

model of the Sun’s current state, evolution and interior

powerful burst of cosmic rays

interdisciplinary branch of physics

reconciliation between dark energy and dark matter

scientific article on the origin of the chemical elements

toroidal cloud of gas or plasma surrounding a planet

ordinary differential equation describing an isotropic spherical body in static gravitational equilibrium in general relativity

comparatively high abundance of elements with atomic numbers near iron.

Surface brightness model in astronomy

observation and interpretation of disparate "messenger" signals, created by different astrophysical processes like electromagnetic radiation, gravitational waves, neutrinos, and cosmic rays

type of constant

Nucleocosmochronology, or nuclear cosmochronology, is a technique used to determine timescales for astrophysical objects and events based on observed ratios of radioactive heavy elements and their decay products. It is similar in many respects to radiometric dating, in which trace radioactive impurities were selectively incorporated into materials when they were formed.

description of the moon's motion

computer-simulated universes

loss of momentum and kinetic energy of moving bodies through gravitational interactions with surrounding matter in space

compression of a massive object by its own gravity

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Ratio in stellar astrophysics

4-meter solar observatory built in the Canary Islands for the European Association for Solar Telescopes

set of minority cosmological theories about the distribution of matter in the Universe

mathematical function

dimensionless quantity used in magnetic convection to represent ratio of the Lorentz force to the viscosity

investigative astrophysics technique