is the sun losing mass?

[spikerz66]

like the title said is our sun loosing its mass due to it converting its mass into energy?

is this how a star "burns out?"

[insane_alien]

yup its losing mass alright. It loses mass via the fusion reaction in the core and also via the solar wind.

 

When a star burns out its because the core has used all its available fuel which causes the star to become unstable and explode.

[YT2095]

Yes.

[swansont]

is this how a star "burns out?"

 

No. The amount of mass converted to radiant energy is small compared to the mass. What will happen is that eventually the hydrogen in the core will have fused into helium (and possibly then on to carbon, oxygen and up to iron) and can no longer sustain the fusion reactions. Once the gravity overwhelms the pressure from fusion, fun things happen. Red giants and then white dwarfs, or supernovae and then neutron stars or black holes ... several different scenarios, depending on the initial mass.

 

http://en.wikipedia.org/wiki/Stellar_evolution

[spikerz66]

ok cool i get it now, i just saw some AMAZING show in the science channel about the evolution of stars so i get it now thanks for all the help guys

[insane_alien]

just remember that nearly all science shows on TV are dumbed down for the public. once you've watched on and thought it was kind of interesting you should go on the internet (wikipedia might be a good place to start if your looking at a new subject) and find out what really happens in the process.

[[Tycho?]]

The sun converts something like 15 000 tons of matter into energy every second. Now this isn't the same rate that it gets rid of this energy, but yeah, its loosing mass.

[Martin]

So you say 15,000 tons of mass converted to energy per second.

 

Tycho that is a good figure to know if it is right.

Lemme see if it agrees with the 3.8 e26 watts in my handbook.

 

A kilogram converts to 9 e16 joules, so a thousand tons to 9 e22 joules

and a million tons converts to 9 e25 joules

 

So my 3.8 e26 watts which I am pretty sure about would translate into

 

38/9 million tons per second = 4,200,000 tons per second

 

So I would say that the sun must lose 4,200,000 metric tons of mass every second JUST TO PROVIDE FOR THE LIGHT THAT WE SEE coming out.

=============

 

so I think your figure of 15 thousand tons per second is way way low.

Maybe I'm missing something. But please check your figure. We should be in closer agreement

 

==============

 

tell this newcomer spiker that he should get a different avatar, this one is in use

[Martin]

a little extra complication is that it takes on the order of tens of thousands of years for a given batch of radiant energy produced in the core to percolate its way out the the surface

 

it starts out as Xray at around 15 million kelvin

and as it percolates out it gets longer wavelength, more and more photons of less and less individual energy,---lower and lower temperature----until by the time it reaches surface it is basically sunlight at roughly 6000 kelvin

 

so the core is converting mass to energy by fusion as far as we know at about the same rate that the sun is radiating energy----over the long term the rates have to balance

 

and there are other ways the sun puts out energy but the main way is this 3.8 e26 watts of sunlight

 

the upshot is that we can be pretty sure that in the core the yield is approximately the same, approximately 3.8e26 watts.

 

thats where I get the 4.2 million tons per second

[J.C.MacSwell]

So you say 15,000 tons of mass converted to energy per second.

 

Tycho that is a good figure to know if it is right.

Lemme see if it agrees with the 3.8 e26 watts in my handbook.

 

A kilogram converts to 9 e16 joules, so a thousand tons to 9 e22 joules

and a million tons converts to 9 e25 joules

 

So my 3.8 e26 watts which I am pretty sure about would translate into

 

38/9 million tons per second = 4,200,000 tons per second

 

So I would say that the sun must lose 4,200,000 metric tons of mass every second JUST TO PROVIDE FOR THE LIGHT THAT WE SEE coming out.

=============

 

so I think your figure of 15 thousand tons per second is way way low.

Maybe I'm missing something. But please check your figure. We should be in closer agreement

 

==============

 

tell this newcomer spiker that he should get a different avatar, this one is in use

 

No wonder it hurts when it hits you straight into the back of the eyeballs!

[spikerz66]

tell this newcomer spiker that he should get a different avatar, this one is in use

 

there.....GOSH!!!!

cant i like al to? (sob)

[weknowthewor]

I don't accept that sun is loosing mass and if so where it is going

[swansont]

I don't accept that sun is loosing mass and if so where it is going

 

Into the EM radiation that you see, or don't see (outside the visible spectrum, or not hitting earth).

[insane_alien]

weknowthewor, it doesn't matter if you accept it or not. reality, frankly, doesn't give a damn.

[Martin]

I don't accept that sun is loosing mass ...

 

your school probably has a Periodic Chart of the chemical elements, or there is a chart online or in a book.

 

I suggest you find a chart and copy down the mass of a hydrogen atom

and multiply that by four

so you have the mass of four hydrogen atoms

 

and then compare that will the mass of a helium atom

 

so then think about it. When, in the core of the sun, four H fuse to form one He, there turns out to be less mass.

 

So how can the sun NOT be losing mass, if it is fusing H into He down in its core?

 

It cant. It has to be losing mass, and at quite a big rate (like some 4 million tons a second) just so it can do enough fusion to provide the energy for all the light that is coming out.

[[Tycho?]]

So you say 15,000 tons of mass converted to energy per second.

 

Tycho that is a good figure to know if it is right.

Lemme see if it agrees with the 3.8 e26 watts in my handbook.

 

A kilogram converts to 9 e16 joules, so a thousand tons to 9 e22 joules

and a million tons converts to 9 e25 joules

 

So my 3.8 e26 watts which I am pretty sure about would translate into

 

38/9 million tons per second = 4,200,000 tons per second

 

So I would say that the sun must lose 4,200,000 metric tons of mass every second JUST TO PROVIDE FOR THE LIGHT THAT WE SEE coming out.

=============

 

so I think your figure of 15 thousand tons per second is way way low.

Maybe I'm missing something. But please check your figure. We should be in closer agreement

 

==============

 

tell this newcomer spiker that he should get a different avatar, this one is in use

 

Whoops, yeah the number I used to do my calculation was mixed around between mass undergoing fusion and mass converted to energy.

 

Wikipedia says 383×10^24 W is the matter energy confusion rate. Which is close enough to your number; what handbook is yours from? I would tend to trust that more than wikipedia for the most part.

[Martin]

;324474']

 

Wikipedia says 383×10^24 W is the matter energy confusion rate. Which is close enough to your number; what handbook is yours from? I would tend to trust that more than wikipedia for the most part.

 

I wish I deserved that much reliance:-)

Here is a chance for you to improve on my precision in the third or fourth decimal place with just a little hunting around.

 

I use an OLD handbook because it is very easy to use and I am familiar with it' date=' and because I usually don't care about more than 3-place precision.

 

It is really a beautiful old handbook

 

Allen's [b']Astrophysical Quantities[/b]

 

My parents gave it to me for Christmas back in the 1970s.

I have the third edition, copyright 1973.

 

C.W. Allen was at that time Emeritus Professor of Astronomy at the University of London.

 

He did a really fine job. I love this book. But most of the numbers have doubtless been improved on.

 

Allen says 3.826(8) x 10²⁶ Watts.

 

you probably know the convention----the central value is 3.826 and the (8) is the standard deviation or estimated uncertainty in the last digit.

So a rough confidence interval would be [3.818, 3.834]

 

It should not be much trouble to find a more recent, presumably better, figure.

 

==========

I was curious so I found this

http://solarscience.msfc.nasa.gov/

 

also the luminosity varies with time---there is that 11-year cycle, so to get more accurate you might have to specify relative to the cycle.

[jackson33]

I don't accept that sun is loosing mass and if so where it is going

 

i understand your point, i think. the energy which is most referred to, will not change the overall mass of the sun. conversion causes this energy and the energy takes no mass with it. however the sun does emit large amounts of matter, throws it into space and what is called solar dust...

[D H]

the energy which is most referred to, will not change the overall mass of the sun. conversion causes this energy and the energy takes no mass with it.

 

The energy results from conversion of mass to energy. Four protons combine over a sequence of reactions called the "proton-proton chain reaction" to form one helium nucleus. This reaction converts 0.7% of the original four protons' mass into energy. For more, see http://en.wikipedia.org/wiki/Proton-proton_chain.