Flashcards
Astr Q4
Cards in this deck (29)
- 1Supernova remnantScattered, glowing remains of a supernoca that occurred in the past.
- 2planetary nebulaeEjected envelope of a red-giant star spread over a volume the size of our solar system
- 3angular momentumTendency of an object to keep rotating, proportional to mass, radius and rotation speed
- 4angular momentum conservationSpeed must change when size changes
- 5stellar evolutionAging process of stars. Slow
- 6alpha particleFast moving packet containing two protons and two neutrons (a helium nucleus)
- 7the triple-alpha process4He+4He=8Be
4H+8Be=12C
3 alpha particles - 8main sequence turn-offHigh luminosity end of the main sequence
- 9the CNO cycleChain of reactions that converts hydrogen into helium using carbon, nitrogen, and oxygen as catalysts.
- 10electron degeneracy pressurePressure produced by the resistance of electrons to further compression once they are squeezed to the point of contact.
- 11Pauli Exclusion PrincipleA rule of quantum mechanics that prohibits electrons in dense gas form from being squeezed too close together.
- 12Red Giant starsGiant star temp so low it glows red
- 13horizontal branch starsGo up/right again. Star is burning helium in its core and fusing hydrogen in a shell surrounding core.
- 14asymptotic giant branch (AGB)Helium burning ceases in core. Star becomes a swollen red giant again
- 15Variable starLuminosity varies with time
- 16Chandrasekhar limit1.4 times mass of sun. White dwarf with less than this will stay a white dwarf forever, bigger will end its life in a supernova
- 17neutron degeneracy pressurePressure due to Pauli Exclusion Principle, when neutrons come in close contact
- 18Neutron StarAfter supernova. Dense ball of neutrons
- 19PulsarEmits radiation in form of rapid pulses with a characteristic pulse period and duration. Radiation beams outwards
- 20Synchrotron RadiationNon-thermal radiation produced by high speed charged particles accelerated in a strong magnetic field.
- 21Core-Collapse Supernova (Type II Supernovae)Highly evolved core implodes and then explodes, destroying the surrounding star
- 22Cepheid Variable StarsIntrinsic variables which pulsate in a predictable way. Cepheid star's period (how often it pulsates) is directly related to its luminosity or brightness
- 23RR Lyrae StarsVariable whose luminosity changes in a characteristic way. All have nearly the same luminosity
- 24Instability StripNarrow, almost vertical region in the HR diagram which contains many different types of variable stars
- 25Period-Luminosity RelationshipRelation between the pulsation period of a Cepheid variable and its absolute brightness
- 26Galaxy Rotation CurvePlot of the orbital speeds of visible stars or gas in that galaxy versus their radial distance from that galaxy's centre
- 27Linear momentum is proportional to mass X velocityangular momentum is proportional to mass X velocity x size
- 28Approximate formula for the main sequence lifetime of stars in terms of their massL=E/T
- 29The Period-Luminosity Relation for Cepheidsperiod increases as luminosity increases).
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- Flashcards on Astr Q4, created by Jeremy Painter on 26/03/2017.
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- Jeremy Painter
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