I know that sun is a star that our planet rotates around, and that stars don't live forever. They all burn out as soon as all of the carbon dioxide turns to helium. When will the sun run out of carbon dioxide? Is it possible to even find out with today's technology?
2006-09-12 20:49:03 · 5 answers · asked by You're giving it all away! 2 in Science & Mathematics ➔ Astronomy & Space
Oh that was hydrogen...i said carbon dioxide...i am sorry
2006-09-12 21:10:28 · update #1
i m not sure if carbon dioxide is involved here
but what i know is the sun is now 4.5 billion yrs old and has another 5.5 billion yrs left
2006-09-12 20:54:04 · answer #1 · answered by Sanjubhai 2 · 1⤊ 0⤋
Stellar evolution is one of the most mature sub-fields of Astronomy. You should be aware that our sun is larger than about 90% of the stars out there, so calling it "average" is perhaps not accurate.
(See figure 9 of http://arxiv.org/abs/astro-ph/0604315) for instance.) A very rough homology relationship (the assumption that all stars fuse hydrogen the same way and have the same internal structure in terms of core size and convection, for instance; this is not terribly accurate but kind of works and is simple) shows main sequence lifetimes scale as roughly 1/mass^2.5 . So, a star 10 times the mass of ours would live about 1/300th as long. A star 1/10th the mass would live about 300 times longer.
The tiny stars are probably fully convective, according to our models, so material from the envelopes is constantly being mixed in with material in the core, giving a much longer main sequence life time, literally TRILLIONS of years.
Yes, our sun will undergo drastic changes in about 4-5 billion years, however the slow changes it undergoes while still on the main sequence will make life uncomfortable on Earth far sooner.
You can read about these changes, and what might be done about it. The latter is in the realm of long term planning, not just fantasy. A concerted research effort could develop this technology in several decades.
Our Sun III. Present and Future http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1993ApJ...418..457S&
Astronomical engineering: a strategy for modifying planetary orbits http://arxiv.org/abs/astro-ph/0102126
2006-09-15 09:57:14 · answer #2 · answered by Mr. Quark 5 · 0⤊ 0⤋
10 billion years (the expected life span of the Sun) is fairly typical for spectral type G (the Sun is G2).
If it follows the typical career path of a Main Sequence Star, the sun will evolve into first a red giant (and when it has used up its hydrogen start to fuse its helium to make carbon and heavier elements) for about 100,000 years and then into a white dwarf star, much cooler and smaller.
2006-09-13 05:10:13 · answer #3 · answered by Amy Morgan 2 · 0⤊ 0⤋
Thousands to billions of years.
A star's lifespan is defined by how massive it is. The more massive the star, the hotter and faster it will burn. The primary fuel that is actually used by stars is hydrogen. By a process called fusion, hydrogen atoms are fused to create helium. When there is no more hydrogen left, the star starts fusing helium to produce lithium and heavier elements. Smaller stars will eventually cool down and die quietly. In a larger star however, fusion will produce elements so heavy that it will collapse under its own gravity, resulting in a supernova, the explosion of a star. In some cases, a black hole is formed.
2006-09-13 04:02:09 · answer #4 · answered by Anonymous · 0⤊ 0⤋
Depends on the size of the star.
The bigger the star the shorter it's lifespan.
Our sun will live for around 10 billion years of which 4.5 billion have already occurred.
Stars ages range from around 0.5 billion years to over 10 billion. The bigger the younger they will most likely be.
2006-09-13 04:12:01 · answer #5 · answered by zach_528 2 · 0⤊ 0⤋