These questions are for discussion during the tutorial on the above topic.
The stars seem fixed in position in the sky.
How then might we measure the distance to the nearest ones?
The Hertzsprung-Russell (HR) diagram relates the colour of a star to its
brightness. It is absolutely fundamental to our understanding of the behaviour
of a star. Consider the following:
What physical property does the colour of a star depend on?
Stars spend typically 90% of their life at a single point in
the HR diagram. What is the most important property of a star which
determines where this point is?
What, then, is the 'Main Sequence'?
Stars form from the collapse of giant clouds of molecular gas
which are only a few tens of degrees above absolute zero. Why do you
think low temperatures are needed for this collapse to occur?
Speculate on the possibility that life forms and biological processes
may occur within molecular clouds. In what ways may the conditions there
hinder or favour biological evolution?
What will happen to the Sun after it leaves the Main Sequence?
When will this occur? Will it explode? Why will the Sun leave
the Main Sequence?
What is a Red Giant and a Planetary Nebula? How are they related?
It has been said that we are all 'star dust'. In what way does
this remark relate to the life cycle of stars, and in particular those
which explode as 'supernovae', producing an expanding blast wave of
gas called a 'supernova remnant'?
'Black Holes' are the endpoints in evolution of the most massive stars.
What makes them 'black'? How then can they be detected? What is at the
surface of a black hole?
Suppose the Sun weighed twice as much as it does, with the Earth orbiting
at the same distance. Discuss some of the effects this would have for
life on Earth? Think about how hot it might be, what colour the sky may
be, how long the year would be, how much UV radiation there may be, and
what effects this all may have on the development of life?
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