astrophysics Flashcards
(24 cards)
what is the doppler effect
it makes the apparent wavelength of a star change when the star moves relative to an observer on earth
what is redshift
if the star is moving away from the earth then the light is shifted towards the red end of the spectrum
wha is the Big Bang theory
that the universe is expanding after exploding from an infinitely small hot dense point
the greater the red shift the..
greater the distance to the star
what is the observed cosmic microwave background radiation
a type of electromagnetic radiation which is a remnant from the early stages of the Universe.
what is the magnitude of a star
a measure of how bright it is in the sky
what does it mean when the magnitude of a star is lower
the star is brighter
what does the apparent magnitude of a star depend on
-the power of a star
-how far away from earth it is
what is the absolute magnitude
a measure of the brightness of stars if they were all the same distance from earth
what are the ranges of absolute magnitude
-10 the most powerful and +20 the least powerful
what is the absolute magnitude of the sun
+4.8
how is energy released by nuclear fusion transferred through space
electromagnetic radiation
what does the wavelength of the EM radiation depend on
the surface temperature of the star
higher temperature stars produce higher energy radiation with..
shorter wavelengths
lower temperature stars produce radiation with..
longer wavelengths
what is the life cycle of a star if its more massive than the sun
nebula, protostar, main sequence star, red super giant, supernova, black hole or neutron star
what is the life cycle of a star if its smaller than the sun
nebula, protostar, main sequence star, red giant, white dwarf, black dwarf
what does the force of gravity do to a nebula
attract the nebula into a dense core
what is constantly changing in a circular orbit
the direction of motion towards the central mass, speed remains constant
what conditions are there in an elliptical orbit
the direction and speeds are changing
what can the force of gravity cause to one mass
for it to orbit a larger mass
what is gravity
the force of attraction which is felt between any two masses
the greater the mass…
the larger the force of gravity
the closer the masses…
the stronger the force of gravity
