Shared Flashcard Set

Details

CHAPTER 14
from book and outline paper
36
Astronomy
Undergraduate 1
05/05/2009

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Cards

Term
How massive can a white dwarf be?
Definition
1.4 times the mass of the sun
Term
What is a neutron star?
Definition
an object that collapsed with such a high pressure that electrons and protons combines to create neutrons
Term
True or false. Neutron stars have extremely high density.
Definition
true
Term
What explains why collapsing cores spin fast?
Definition
the conservation of angular momentum
Term
What are pulsars?
Definition
neutron stars that spin very fast and emit pulses of radiation
Term
What are glitches in the pulsar period probably from?
Definition
the internal makeup of neutron star
Term
Is pulsar rotation gradually increasing or slowing?
Definition
slowing
Term
What is 99.9% of the energy released by a pulsar due to?
Definition
pulsar winds
Term
What are pulsar emissions modeled after?
Definition
lighthouse
Term
What are the remnants of a supernova from AD 1054 called?
Definition
the Crab Pulsar
Term
Why do some neutron stars move rapidly through space?
Definition
non-uniformity of supernova explosion
Term
what are neutron stars with the strongest magnetic fields called?
Definition
magnetars
Term
In a binary pulsar, does the pulsar period lengthen when the pulsar is moving toward or away from earth?
Definition
away
Term
TRUE OR FALSE: Some pulsars have planets orbiting them
Definition
true
Term
Neutron stars cant exist with masses greater than...?
Definition
3Msun
Term
Objects greater than 3Msun will collapse into a single point called?
Definition
singularity
Term
Objects greater than 3 solar masses are known as what?
Definition
black holes
Term
If earths radius decreases, what happens to the escape velocity from its surface?
Definition
it decreases
Term
what is the limiting radius where the escape velocity reaches the speed of light?
Definition
schwarzchild radius
Term
what is an event horizon?
Definition
the outer boundary of a black hole
Term
if a supernova remnant doesnt contain a neutron star, what could it contain?
Definition
a black hole
Term
true or false. The gravitation fields of a black hole and a star of the same mass are indistinguisable at far distance.
Definition
true
Term
The vertical stretching of an object falling toward a black hole is called what?
Definition
spaghetti-fication
Term
true or false: time will stop at the event horizon.
Definition
true
Term
Wavelengths at an event horizon are ______ shifted.
Definition
red
Term
why cant a black hole be observed directly?
Definition
bc no light can escape a black hole
Term
why cant a black hole be observed directly?
Definition
bc no light can escape a black hole
Term
Black holes and neutron stars part of a binary system are usually strong sources for what?
Definition
xrays
Term
what is created as accreted matter impacts onto a neutron star surface?
Definition
an xray flash
Term
accretion disks around black holes are strong sources for what?
Definition
xrays
Term
what is probably related to the deaths of very massive stars?
Definition
gamma-ray bursts
Term
The deaths of very massive stars are called what?
Definition
hypernovae
Term
what three quantities are black holes determined by?
Definition
1. mass
2. angular momentum
3. electric charge
Term
what are the fastest pulsars?
Definition
millisecond pulsars
Term
what are rotating black holes called?
Definition
kerr black holes
Term
what are Xray bursterS?
Definition
where mass transfer puts matter on the surface of the neutron star
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