Larissa's section - Test 2 Flashcards
(40 cards)
why do stars twinkle?
light from space travels in a straight line, but our atmosphere redirects and scatters this line
why don’t planets twinkle?
because they are much closer than stars
nuclear fusion from H into He is combining which two atoms?
deuterium and tritium
where does fusion happen and why?
core
outer layers compress the core so temps and pressure are high enough so fusion can happen
the colour of a star depends on its?
surface temperature
what does brightness depend on?
brightness in the sky: distance
intrinsic: size and temp
write the flux equation on your cheat sheet?
yes
stars at their biggest are the size of ? and stars at smallest are the size of?
our solar system,
a gas giant
what are the three regions of the HR diagram
- supergiants (top right)
- main sequence
- white dwarves (bottom left)
describe binary stars
2 stars orbiting their centre of mass
what is more common, less massive stars or more massive stars
less massive
what is heliosiesmology
used to study the interior of the sun by seeing how pressure waves are travelling in the interior, telling us how it looks inside
how long is the suns lifetime?
10 billion years about, we are halfway through
what is a supernova?
extremely bright explosion
how does LMS planetary nebula phase compare to supernova phase of HMS?
LMS phase = billions of years
HMS phase = 1s to one months
true or false, atoms are more empty than our solar system
true
why does biological life depend on the death of stars?
all elements apart from H and He come from the death of a star in some way.
- carbon and nitrogen from dying LMS
- oxygen from dying HMS
- H from big bang
why do objects in space look similar?
because stars are made from stuff spewed out by other stars
what doesn’t contribute to space recycling
brown dwarves, white dwarves, neutron stars and black holes
how can SN cause new star formation?
its shockwave can compress nearby gas clouds and cause new stars to form
is the sun a sibling or parent and why?
the earth was born from the same gas cloud as the sun, so siblings
true or false, some molecular clouds have no rotation
false, all will have SOME rotation
what are interstellar objects?
objects that originate from outside our solar system, visit it, but gravity isn’t enough to keep it there and it leaves with a hyperbolic orbit
what is a bowshock shape?
shape like the one in front of a meteor
