the end of our sun-white dwarf or red giant?

From "The case of the missing neutrino" by John Gribbon, written in
1997, our sun would turn into a white dwarf after death. From "Parallel
worlds" by Michio Kaku, written in 2005, our sun would turn into a red
giant after death.

Which one is correct? Or are both cases possible? Or white dwarf was a
previous theory while red giant is a more recent one?

"kajlina" wrote in message
oups.com...
| From "The case of the missing neutrino" by John Gribbon, written in
| 1997, our sun would turn into a white dwarf after death. From "Parallel
| worlds" by Michio Kaku, written in 2005, our sun would turn into a red
| giant after death.
|
| Which one is correct? Or are both cases possible? Or white dwarf was a
| previous theory while red giant is a more recent one?

"After death" is meaningless, but yes, both are possible. It
is inevitable that eventually all the hydrogen "fuel" is converted to
helium and so a helium core is gradually growing in our sun.
Inside that is an even heavier but smaller core as the helium is
"consumed" and the final state is thought to be a neutron star
like Matryoshka dolls. However, the star can go supernova
before that happens and the entire process is largely conjecture.
This is an obvious expansion:
http://antwrp.gsfc.nasa.gov/apod/ap011227.html

Androcles

Best answer to date: Both...

The ~consensus is that our sun will eventually reach a red giant stage
and
then move on to a red supergiant stage, after which it will very
gradually
become a white dwarf. This last stage will last for many tens of
billions
of years, as it slowly cools off. And no, it will not ever go
supernova.
It is not nearly massive enough for any type II SN event, and for a
dwarf to
go type Ia SN, a second or companion star is needed in fairly close
orbit, to send lots of material onto the dwarf, to push it over the
Chandra-
sekhar mass limit, ~ 1.3 Msol. One site that covers some of this is

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

Cheers.

In article .com,
kajlina wrote:
From "The case of the missing neutrino" by John Gribbon, written in
1997, our sun would turn into a white dwarf after death. From "Parallel
worlds" by Michio Kaku, written in 2005, our sun would turn into a red
giant after death.

Which one is correct? Or are both cases possible? Or white dwarf was a
previous theory while red giant is a more recent one?

Gribbon is correct - the Sun will become a white dwarf after death.
However it will become a red giant while dying. Its red giant phase
will be fairly brief, perhaps a few million years. The final white
dwarf phase will last many billion years.


--
----------------------------------------------------------------
Paul Schlyter, Grev Turegatan 40, SE-114 38 Stockholm, SWEDEN
e-mail: pausch at stockholm dot bostream dot se
WWW: http://stjarnhimlen.se/

wrote in message
ps.com...
| Best answer to date: Both...
|
| The ~consensus is

Eat ****, 100,000,000,000 flies can't be wrong.

On 2006-10-26, kajlina wrote:
From "The case of the missing neutrino" by John Gribbon, written in
1997, our sun would turn into a white dwarf after death. From "Parallel
worlds" by Michio Kaku, written in 2005, our sun would turn into a red
giant after death.

Which one is correct? Or are both cases possible? Or white dwarf was a
previous theory while red giant is a more recent one?


For the Sun, "red giant" is a stage on the way to "white dwarf".

http://observe.arc.nasa.gov/nasa/spa...ath_intro.html

is helpful.

Bud

The Sun isn't massive enough to form a neutron star. Next is the red
giant stage, then a white dwarf.

Saul Levy


On Thu, 26 Oct 2006 06:07:43 GMT, "Androcles"
wrote:


"kajlina" wrote in message
roups.com...
| From "The case of the missing neutrino" by John Gribbon, written in
| 1997, our sun would turn into a white dwarf after death. From "Parallel
| worlds" by Michio Kaku, written in 2005, our sun would turn into a red
| giant after death.
|
| Which one is correct? Or are both cases possible? Or white dwarf was a
| previous theory while red giant is a more recent one?

"After death" is meaningless, but yes, both are possible. It
is inevitable that eventually all the hydrogen "fuel" is converted to
helium and so a helium core is gradually growing in our sun.
Inside that is an even heavier but smaller core as the helium is
"consumed" and the final state is thought to be a neutron star
like Matryoshka dolls. However, the star can go supernova
before that happens and the entire process is largely conjecture.
This is an obvious expansion:
http://antwrp.gsfc.nasa.gov/apod/ap011227.html

Androcles

What do flies know?

Saul Levy


On Thu, 26 Oct 2006 11:36:52 GMT, "Androcles"
wrote:


wrote in message
ups.com...
| Best answer to date: Both...
|
| The ~consensus is

Eat ****, 100,000,000,000 flies can't be wrong.