February Review - Vesna Questions Flashcards
how long is our suns life?
10 billion years, it has 5 billion to go.
what does our sun burn in its core?
hydrogen
suns life:
- main sequence
- red giant
- helium core burning
- planetary nebula leaves white dwarf behind
what is heavier? higher mass small white dwarf or lower mass big white dwarf?
higher the mass, heavier it is.
are binary stars common?
over half are.
what is the most combustable element in the universe?
carbon.
how old is our universe?
13.8 billion yrs old.
what are the two types of star clusters?
open and globular.
what is a supernova called if it has no luminosity?
standard candle.
sun’s white dwarf will be the size of?
Earth.
what is an accretion disk?
surrounds white dwarf while it’s binary star looses mass.
what is a nova?
when the temperature of an acreded matter eventually becomes hot enough for hydrogen fusion. (which is temporary brightening)
the bigger the star, the ___ they live, and the smaller the star the ___ they live.
shorter, longer.
out of OBAFGKM, what star is our sun?
G.
which hr diagram is the oldest and which is the youngest?
the one with the most is the oldest, and the one with the least is the youngest.
what do cluster hr diagrams give us?
snapshot of stellar evolution.
does iron fuse into anything? how big is an iron nucleus?
no, and huge.
what is the mass of a white dwarf?
mass of sun.
size of white dwarf?
size of earth.
size of neutron star?
up to 3 solar masses.
what is the most dense object?
neutron star.
what is a pulsar?
rotating neutron star. –> “clocks of the universe”
the majority (99%) of supernovas energy are?
neutrinos.
what is the speed of light?
671 million miles/hr.
what is the equivalence principle?
the effects of gravity are exactly equivalent too the effects of acceleration.
explain gravity.
more mass = more distortion because mass bends space time.
what is the essence of general gravity?*
matter tells space how to curve, space tells matter how to move.
what is gravitational lensing?
mirage of a galaxy because light follows the straightest path possible, gravitational lensing occurs when it is not in a perfect line.
