Why Will Sun Get Hotter?

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Westwind
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Why Will Sun Get Hotter?

Post by Westwind » Thu Feb 18, 2010 1:55 pm

I've read that scientists believe the Sun's temperature increases by about 10 percent every billion years or so. In about a billion years, they estimate the Sun will get so hot that it will boil away the oceans on Earth.

What is causing the Sun's temperature to increase over time?

--Bill

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BMAONE23
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Re: Why Will Sun Get Hotter?

Post by BMAONE23 » Thu Feb 18, 2010 2:47 pm

Some of it might have to due with the fusion process and the fact that Fusing heavier elements requires/creates greater heat

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Chris Peterson
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Re: Why Will Sun Get Hotter?

Post by Chris Peterson » Thu Feb 18, 2010 3:01 pm

Westwind wrote:I've read that scientists believe the Sun's temperature increases by about 10 percent every billion years or so. In about a billion years, they estimate the Sun will get so hot that it will boil away the oceans on Earth.

What is causing the Sun's temperature to increase over time?
The Sun is (currently) producing its energy by fusing hydrogen into helium. Helium is denser than hydrogen, and sinks to the core. This results in greater gravitational compression, which is offset by a greater rate of fusion to maintain a balance.

In general, over the main sequence lifetime of a star, the gradual increase in helium results in a corresponding increase in fusion rate, and therefore a gradual increase in temperature.
Chris

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Westwind
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Re: Why Will Sun Get Hotter?

Post by Westwind » Thu Feb 18, 2010 3:26 pm

Thanks very much, Chris.

I've volunteered to give a presentation about the Sun for our astronomy club at a county park system nature center next month. I plan to discuss the life cycle of the Sun, mentioning that the Sun will become hotter over time, etc.

I figure someone in the audience might ask why the Sun will become hotter, so I want to be prepared. I'm an amateur astronomer, so preparing my PowerPoint presentation has been a enjoyable learning process for me.<s>

Thanks again.

--Bill
Cuyahoga Astronomical Association

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Orca
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Re: Why Will Sun Get Hotter?

Post by Orca » Sat Feb 20, 2010 3:44 pm

You might try comparing the life sequences of low, medium (like our sun), and high-mass stars. Initial mass is a critical factor in the life cycle, behavior, lifespan, and of course death of a star.

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Re: Why Will Sun Get Hotter?

Post by Vaccum Explorer » Wed Feb 24, 2010 7:55 pm

I s this another Globle Warming Story :D

Westwind
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Re: Why Will Sun Get Hotter?

Post by Westwind » Thu Feb 25, 2010 12:40 am

Thanks for your suggestion, Orca.

--Bill