Astro Ch 13 & 14
Terms
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- worm hole
- a hypothetical connecting passage between black holes and other places in the universe
- special theory of relativity
- a description of mechanics and electromagnetic theory formulated by Einstein according to which measurements of distance, time, and mass are affected by the observer's motion
- spacetime
- the concept from special relativity that space and time are both essential in describing the position, motion, and action of any object or event
- nova
- a star in a binary system that experiences a sudden outburst of radient energy, temporarily increasing its luminosity
- intermediate-mass black hole
- a black hole with a mass between a few hundred and few thousand solar masses
- planetary nebula
- a luminous shell of gas ejected from an old, low-mass star
- cosmic ray shower
- groups of particles from Earth, whose radius equals the distance traveled by light since the Big Bang
- virtual particle
- a particle and its antiparticle, created simultaneously in pairs and which quickly disappear without a trace
- neutron star
- a nuclear particle with no electric charge and with a mass nearly equal to that of the proton
- singularity
- a place of infinate curvature of spacetime in a black hole
- gravitational wave
- ripples in the overall geometry of space produced by nonspherical moving objects
- accretion disk
- an orbiting disk of matter spiraling in toward a star or black hole
- cosmic censorship
- the belief that the only connection between a black hole and the universe is the black hole's event horizon
- ergoregion
- the region of space immediately outside the event horizon of a rotating black hole where it is impossible to remain at rest
- supermassive black hole
- a black hole whose mass exceeds 1000 solar masses
- premordial black hole
- a relatively low-mass black hole hypothetically formed at the beginning of the universe
- Type Ia supernova
- a supernova occurring after a white dwarf accretes enough mass from a companion star to exceed the Candrasekhar limit
- Kerr black hole
- any rotating, uncharged black hole
- event horizon
- the location around a black hole where the escape velovity equals the speed of light; the boundary of a black hole
- supernova
- a stellar explosion during which a star suddenly increases its brightness
- glitch
- a sudden speedup in the period of a pulsar
- x-ray burster
- a neutron star in a binary star system that accretes mass, undergoes thermonucler fusion on its surface, and therefore emits short bursts of x-rays
- white dwarf
- a low-mass stellar remnant that has exhausted all its thermoneuclear fuel and contracted to a size roughly equal to the size of the Earth
- gamma-ray burst
- a short burst of gamma rays; the sources of the bursts are outside our galaxy
- photodisintegration
- the breakup of nucleus in the core of a massive star due to the effects of energetic gamma rays
- quark
- a particle that is a building block of the heavy nuclear particles such as protons and neutrons
- Type II supernova
- a supernova occurring after a massive star's core is converted to iron
- Chandrasekher limit
- the maximum mass of a white dwarf, about 1.4 M
- gravitational redshift
- the reshift of photons leaving the gravitational field of any massive object, such as a star or black hole
- helium shell flash
- the explosive ignition of helium fusion in the core of a low-mass, giant star
- helium shell fusion
- helium fusion that ours in a thin shell currounding the core of a star
- pulsar
- a pulsating source associated with a rapidly rotating neutron star with an off-axis magnetic field
- neutron degeneracy pressure
- a pwerful pressure produced by degenerate neutrons
- secondary cosmic ray
- particles from the Earth's atmosphere given high speeds Earthward by cosmic rays from space
- Schwarzschild black hole
- any nonrotating, uncharged black hole
- cosmic ray
- high speed particles traveling through space
- Hawking process
- the formation of real particles from virtual ones just outside a black hole's event forizon; the means by which black holes evaporate
- general theory of relativity
- a description of spacetime formulated by Einstein explaining how gravity affects the geometry of space and the flow of time
- asymptotic giant branch (AGB) star
- a red giant star that has completed core helium fusion and has re-expanded for a second time
- black hole
- an object whose gravity is so stron that the escape velocity from it exceeds the speed of light
- lighthouse model
- the explanation that a pulsar pulses by rotating and funneling energy outward via magnetic fields that are not aligned with the rotation axis