ASTR 1010 Final Vanderbilt Latest Update -

ASTR 1010 Final Vanderbilt Latest Update -

Questions and Verified Correct Answers Golden Ticket to Guaranteed A+ Verified by Professor

baryonic matter - CORRECT ANSWER: normal matter

(protons/electrons/neutrons/stuff!)

Bullet Cluster - CORRECT ANSWER: 3 mass measrmts: luminous matter in peripheral gxys, x-ray gas in the center of collision (10x more than gxys), and gravitational lensing of other objects (lensing mass 5x gas's mass)

most of lensing occurs around galaxies; galaxies have most of mass, which we can't see (dark) and which can't escape gxys (cold)

Cannon - CORRECT ANSWER: 1901, created OBAFGKM stellar classification system,

adding fractnl gradatns and finally organizing spectral types from hot to cool; would give x-axis of H-R diagram, most important diagram in all of astrophysics

cepheid variable stars - CORRECT ANSWER: variable star w/ irregular varblty trend, rapidly brightening, fading progressively slower till 3/4 down, then rapidly finishing/repeating; variatn related to intrinsic luminosity, i.e. their size/temp changing

Copernicus - CORRECT ANSWER: 1500s, hypothesized heliocentric universe; had no

hypothesis on universe age; nudged scientists to consider the universe having a beginning instead of being eternal

dark energy + evidence - CORRECT ANSWER: a mysterious repulsive force that

appears to be causing the expansion of the universe to accelerate

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Type Ia supernovae as standard candles; Hbl law says they should be moving faster there; inverse square law for light dictates that dimmer = farther; calculated dstncs to things are even farther than their redshift predicts; they are being pushed away

dark matter + evidence - CORRECT ANSWER: matter (gravity, attractive force) that does not give off electromagnetic radiation but is quite abundant in the universe

rotation curves, ultra-faint galaxies, gravitational lensing, Coma Cluster + Zwicky, Bullet Cluster

Dicke and Peebles - CORRECT ANSWER: 1965, made the connection btwn

Penzias/Wilson's radio noise & CBR

Doppler shift - CORRECT ANSWER: v/c= (lambda[sub:observed] - lambda[sub:rest]) / lambda[sub:rest] ; wavelength of obsrvd object increases with speed of the object

early phases of Big Bang - CORRECT ANSWER: inflationary epoch: 10^-35 s, universe expands beyond speed of light for reasons unknown

particle creation epoch: 5 s, T > 1,000 bil K, photons have so much energy that they can turn into p/n/e's and back; higher energy = higher mass, but as univrs expands, photon wvlngths stretch, losing energy & losing ability to convert to particles at all

element creation epoch: 100 s, T < 6 bil K; n's too unstable to exist w/o fusing w/ p, so they either do that or fall apart into p/e's; protons have enough energy to combine into H, 2H & He, even some Li/Be;

combination/recombination epoch: 380,000 y, T < 1 bil K, p/e's combine to form H, e's absorb photons w/ enough energy to free them, H falls apart, univrs expands/cools, H keeps reforming/falling apart with photons having less and less energy to free to e's each time, until energy is too little and photons can't be absorbed anymore

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