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as you enter the Event Horizon of a black hole oh, what causes the effect of "spaghettification"?
tidal gravitational forces
which is not a possible trigger for star formation?
who was it that hired Kepler to analyze his planetary position data?
Austin has a red photon and Courtney has a blue photon. who's photon has a larger energy and whose photon has a larger freq.
Courtney's photon has a larger energy. and Austin's photon has larger wavelength
what are the 2 principles of special relativity?
Constancy of the speed of light and Principle of Relativity
Rachel's star has an absolute magnitude of 4.5 and Seth's has an magnitude of 6.5. which of the following is definitely true?
Rachel's star is intrinsically brighter than Seth's star.
stars heat up as they form by
gravitational potential energy being converted into kinetic energy, then into heat via friction
what two properties dictate directly how long a star will stay on the main sequence?
its mass and its luminosity
State the Stellar spectral classes in order of hottest to coolest
at the center of a black hole is
what method is used to determine the distance of nearby Stars?
according to Wiens law
as the temperature of a body increases, its spectral Peak shift to Shorter wavelengths
what are the things you need to know to compute Newton's gravitational force between two objects?
mass of the two objects and the distance between them
what is the fuel used in the cno-cycle process and what does it produce?
fuel is hydrogen and it produces helium and energy
according to Newton's 2nd law of motion
a net force on an object is equal to the mass of that object times the acceleration it produces
the predominant color of emission nebula is
red from the hydrogen Balmer H (x) line
in the famous Michelson and Morley experiment the scientist were trying to
measure the absolute velocity of the Earth through the Aether
which of the following is a valid H-R diagram
plot of Luminosity on the y-axis and the color index on the x-axis
an internal reference frame is a frame which
is at rest or moving with a constant uniform motion (velocity)
the Doppler effect can be used to measure a star's
to determine the sum of the masses of a visual binary star system, we need to measure for the system
the period and the semi-major axis
list the four properties that all waves have
wavelength frequency speed of propagation and energy flux
the triple Alpha process is where
a red giant star Burns helium into a carbon in its core or in a shell around the core
you point out 3 stars in the sky 1. yellowish 2. reddish-orange 3. blueish-white
3 is the hottest then 1 then 2 is the coolest
just after leaving the main sequence, Stars expand and become red giant stars because
they stop burning H to He in their cores and start burning H to He in a shell around the core, thus increasing their pressure and so they expand
what Stella parameter can you only get from observing a binary star system
what is the element that CAN'T be used in thermo nuclear reactions in the core of a star to produce energy
which of the following is the best model to explain pulsar?
what kind of object exists at the center of a planetary nebula
a white dwarf
which of the following objects CAN NOT be used to determine the distance to a Galaxy
who was the first person to map the sky and radio waves
what are the only three properties that a black hole can have?
Mass, electric charge, spin
what kind of Stellar system was the first black hole candidate found in
binary star system
in Hubble's Law, what two things of a galaxy are proportional to each other?
recessional velocity and distance
what type of star becomes a planetary nebula?
low mass star
pulsars can be spun up after they have formed by
accreting matter from a companion star in a binary star system
what kind of particles(besides photons) did astronomers detect from supernova 1987a?
which of the following is NOT a site where black holes
centers of planetary nebula
what "animal" did Kip Thorn using his diagram which was a fanciful analog a gravitational implosion of a star to form a BH?
what determines whether a particular region of an Interstellar Cloud can collapse and form a star?
the amount of gravity pulling inward compared to the gas pressure pushing outward
the Luminosity of a star is
total energy output into all directions overall wavelength
the two processes by which main sequence stars generate energy in their cores are:
the proton-proton chain for low mass stars and the CNO-cycle for high mass stars
list the 4 different types of galaxies
What event caused physicists to drop black hole research for close to 20 years?
what is NOT likely to be at the center of a supernova remnant?
what is the product of the triple Alpha process
who were the two physicists that fought over whether black holes really exist
Robert Oppenheimer and John Wheeler
a type Ia Supernova is
a white dwarf blowing itself up after it has accumulated too much Mass from its binary companion
how many times does a low mass star like our sun get to be a red giant star
what is special about the ergosphere of a spinning black hole?
Nothing can “fall” into it, it has to enter its orbit
our Milky Way galaxy is headed for a collision with which of the following galaxies
Andromeda Galaxy (M31)
which type of galaxies currently has very little or no star formation occurring in it?
what are the two distances one can specify for a very distant object?
speed of light and Co-moving distance
which of the following types of objects is thought to be currently extinct in the universe
how many times does a very high mass star get to be a red giant star
all pulsars are found inside Supernova
black holes "lose" deformities of their Event Horizon via gravitational radiation
a spinning black hole's Event Horizon is perfectly spherical
Cyg X-1 is a black hole candidate
there are several objects in our galaxy known to be black holes with absolute certainty
galaxies are distributed uniformly throughout space
in Galactic collisions, head-on collisions of individual stars are very rare
how fast a AGN can change its brightness tells you what about AGN?
how small the central engine is
objects and spiral galaxies move______ in the disk of the Galaxy, and move______ in the Bulge and Halo of the Galaxy
uniformly and chaotically
for an accretion disk, the Eddington Luminosity limit is reached when
the pressure of the photons leaving the accretion disk stops in the flow of matter to the accretion disk
what does AGN stand for?
Active Galactic Nuclei
which of the following is at Madill of gamma ray bursts?
two neutron stars in a binary system merging to form a black hole
black holes, white dwarfs, and neutron stars are dense compact objects. List them in order of increasing Mass, start low
white dwarfs, neutron stars, black holes
in a spiral galaxy, young hot stars are found in
the galactic disk
the same made Famous by John Wheeler which means that black holes have very few properties is
"black holes have no hair"
which Galaxy is currently on collision course with our Milky Way galaxy?
the Andromeda Galaxy
which massive star will be a main sequence star the longest
black holes are a solution to which set of equations?
general relativity equations
gravitational lensing is caused by
bending of space-time around a massive object
who mathematically proved that every event horizon(black hole) must have a singularity?
what is the difference between Oppenheimer's singularity and the BKL singularity?
Oppenheimer's Singularity is static independent and BKL singularity is time dependent
what is a wormhole? have we ever detected one? how do you make one be "stable"?
a wormhole is a shortcut through space. no we have never detected one. you make one stable by aligning the throw with the Exotic material
what is the difference between the apparent Horizon and the absolute Horizon
the apparent Horizon is where we see it and the absolute Horizon is where it is directly
what aspect of black holes did Stephen Hawking indicate could not decrease in a fix the region of SpaceTime?
the surface area of the absolute Horizon
what is entropy and the second law of Thermodynamics that governs it?
entropy is the amount of disorder in a system
thermodynamics says it can only increase or stay the same
do black holes exist forever once they are created?
no but last a really long time
what is a paradigm?
Viewpoint or way to solve a problem
what elements usually make up a paradigm for physicists
1. Accepted laws and theories
2. Pictures and diagrams
3. Examples of similar problems
is "your" Paradigm better than "my" paradigm?
no, not if you come up with the same answer
how many fundamental forces are there and what are they?
1. Gravity (weakest)
2. Strong force (1)
3. Weak force (2)
how many forces would physicists like to have?
what is the "inflation" model and why was it developed?
the inflation model is the universe expanded by 50 orders of magnitude
it was developed because it solves isotropic problems (flattens them)
where did all the mass in the universe come from?
inflationary phase during Universe expansion
where did the Big Bang take place?
what special event happened~ 380,000 years after the big bang?
why do we think the universe is filled with dark energy?
because it makes up all of what we don't see
has the expansion of the universe been constant?
no because it is speeding up
what does the time scale of brightness variation tell you about AGN?
size of the engine generating the energy
what is the Eddington limit?
limit on luminosity
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