Page 31 - Curriculum Visions Dynamic Book

gravitational field The region surrounding a body in which that body’s gravitational force can be felt.
neUtrinos An uncharged fundamental particle that is thought to have no mass.
neUtrons Particles inside the core of an atom that are neutral (have no charge).
neUtron star A very dense star that consists only of tightly packed neutrons. It is the result of the collapse of a massive star.
nova (pl. novae) A star that suddenly becomes much brighter, then fades away to its original brightness within a few months.
protons Positively charged particles from the core of an atom.
red giant A cool, large, bright star at least 25 times the diametre of our Sun.
spiral galaxy A galaxy that has a core of stars at the center of long curved arms made of even more stars arranged in a spiral shape.
sUpernova A violently exploding star that becomes millions or even billions of times brighter than when it was younger and stable.
Supernovas
Iron only forms in the most massive of stars. When it does, it stops the reaction, and the core starts to cool rapidly. As a result, there is nothing to counteract the force of gravity. As the star nears the end of its planetary nebula phase, it collapses inward (implodes), creating a very small, extremely dense rotating core made almost entirely of neutrons—a neUtron star. At the same time, showers of neUtrinos are produced that add energy to the outer shell as it implodes and create an outward force that throws the shell into space to produce the most gigantic explosion in the Universe.
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