the journal of literature and the arts at saint david ’ s school
Scene 3 : Main-Sequence Star
I remember when I was a main-sequence star , which is a star in the middle of its life — for example , your closest star , the sun . Similar to your adulthood , when I was a main-sequence star I shined constantly by converting hydrogen to helium through thermonuclear activity . This type of star exists longer than the earth has existed because the star lasts for 5 to 15 billion years ! As a main-sequence star , I continued to burn for another 10 billion years after the nuclear fusion stage had begun , until the central temperature had reached 27 million degrees Fahrenheit . At this stage , the thermal pressure balanced the gravitational contraction forces . The length of a main-sequence star ’ s life depends on its size and the amount of hydrogen it has to burn . Once it runs out of hydrogen to burn , gravitational forces become greater than the thermonuclear energy being produced from the star ’ s core , and the star begins to collapse . This marks the next stage of a star ’ s life similar to old age for a human . Now I am going to hand it over to a friend who is a black hole , and he is going to lead you through the later stages of our life cycle .
Scene 4 : Red Supergiant
Thanks , Bowen ! Hi , I am Hayden . Even though I ’ m just an old black hole , I can remember myself as a supergiant like it was yesterday . After my main sequence , I began the second half of my life . Due to my large size , I became a red supergiant . A star ’ s mass has to be at least five times that of the sun to become a red supergiant as I did . I spent most of my life fusing hydrogen into helium , but eventually I ran out . Because of this , I began to cool off , and I expanded to more than 400 times my original size ! To stay alive , I began fusing helium in my core . After I expanded and cooled off enough , I
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