Star density as a function of radius?

Does anyone have any references for graphs of density as a function of radius,
for various stars including the sun?

Many thanks,
--
I.N. Galidakis

"I.N. Galidakis" wrote in message
news:1224236529.863974@athprx03...
Does anyone have any references for graphs of density as a function of
radius,
for various stars including the sun?

Many thanks,
--

Try this data - copied from AQ3
http://www.astd60.dsl.pipex.com/structure_of_sun.htm

The source is quite old (1972), but maybe Chris Peterson or Mike Dworetsky
will be able to come up with more recent sources.

OG wrote:
"I.N. Galidakis" wrote in message
news:1224236529.863974@athprx03...
Does anyone have any references for graphs of density as a function of
radius,
for various stars including the sun?

Many thanks,
--

Try this data - copied from AQ3
http://www.astd60.dsl.pipex.com/structure_of_sun.htm

The source is quite old (1972), but maybe Chris Peterson or Mike Dworetsky
will be able to come up with more recent sources.

Many thanks to you and Sam. Exactly what I was looking for.
--
I.N. Galidakis

I.N. Galidakis wrote:
OG wrote:
"I.N. Galidakis" wrote in message
news:1224236529.863974@athprx03...
Does anyone have any references for graphs of density as a function of
radius,
for various stars including the sun?

Many thanks,
--

Try this data - copied from AQ3
http://www.astd60.dsl.pipex.com/structure_of_sun.htm

The source is quite old (1972), but maybe Chris Peterson or Mike Dworetsky
will be able to come up with more recent sources.

Many thanks to you and Sam. Exactly what I was looking for.

By the way, does anyone recognise the type of the distribution? It looks to me
like a Fermi distribution (isn't it reasonable to assume it is?)

Many thanks,
--
I.N. Galidakis

"OG" wrote in message
...

"I.N. Galidakis" wrote in message
news:1224236529.863974@athprx03...
Does anyone have any references for graphs of density as a function of
radius,
for various stars including the sun?

Many thanks,
--

Try this data - copied from AQ3
http://www.astd60.dsl.pipex.com/structure_of_sun.htm

The source is quite old (1972), but maybe Chris Peterson or Mike Dworetsky
will be able to come up with more recent sources.



There may have been some small updates, but the basic density vs R structure
is as given in the table.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

"I.N. Galidakis" wrote in message
news:1224321381.254055@athprx03...
I.N. Galidakis wrote:
OG wrote:
"I.N. Galidakis" wrote in message
news:1224236529.863974@athprx03...
Does anyone have any references for graphs of density as a function of
radius,
for various stars including the sun?

Many thanks,
--

Try this data - copied from AQ3
http://www.astd60.dsl.pipex.com/structure_of_sun.htm

The source is quite old (1972), but maybe Chris Peterson or Mike
Dworetsky
will be able to come up with more recent sources.

Many thanks to you and Sam. Exactly what I was looking for.

By the way, does anyone recognise the type of the distribution? It looks
to me
like a Fermi distribution (isn't it reasonable to assume it is?)

Many thanks,
--
I.N. Galidakis


It's more like a polytrope, or gas sphere, structure. You can look
polytropes up--it's the usual starting place for stellar structure courses,
but requires that you know something about differential equations. Real
stars are not polytropes, in part because the equation of state may involve
degenerate gases rather than perfect gases.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

Mike Dworetsky wrote:
"I.N. Galidakis" wrote in message
news:1224321381.254055@athprx03...
I.N. Galidakis wrote:
OG wrote:
"I.N. Galidakis" wrote in message
news:1224236529.863974@athprx03...
Does anyone have any references for graphs of density as a function of
radius,
for various stars including the sun?

Many thanks,
--

Try this data - copied from AQ3
http://www.astd60.dsl.pipex.com/structure_of_sun.htm

The source is quite old (1972), but maybe Chris Peterson or Mike
Dworetsky
will be able to come up with more recent sources.

Many thanks to you and Sam. Exactly what I was looking for.

By the way, does anyone recognise the type of the distribution? It looks
to me
like a Fermi distribution (isn't it reasonable to assume it is?)

Many thanks,
--
I.N. Galidakis


It's more like a polytrope, or gas sphere, structure. You can look
polytropes up--it's the usual starting place for stellar structure courses,
but requires that you know something about differential equations. Real
stars are not polytropes, in part because the equation of state may involve
degenerate gases rather than perfect gases.

Many thanks. I got it:

http://en.wikipedia.org/wiki/Polytrope
--
I.N. Galidakis

On Oct 18, 12:42*pm, "Mike Dworetsky"
wrote:
"I.N. Galidakis" wrote in message

news:1224321381.254055@athprx03...



I.N. Galidakis wrote:
OG wrote:
"I.N. Galidakis" wrote in message
news:1224236529.863974@athprx03...
Does anyone have any references for graphs of density as a function of
radius,
for various stars including the sun?

Many thanks,
--

Try this data - copied from AQ3
http://www.astd60.dsl.pipex.com/structure_of_sun.htm

The source is quite old (1972), but maybe Chris Peterson or Mike
Dworetsky
will be able to come up with more recent sources.

Many thanks to you and Sam. Exactly what I was looking for.

By the way, does anyone recognise the type of the distribution? It looks
to me
like a Fermi distribution (isn't it reasonable to assume it is?)

Many thanks,
--
I.N. Galidakis

It's more like a polytrope, or gas sphere, structure. *You can look
polytropes up--it's the usual starting place for stellar structure courses,
but requires that you know something about differential equations. *Real
stars are not polytropes, in part because the equation of state may involve
degenerate gases rather than perfect gases.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)

As usual,uninteresting junk by a junk merchant.

The problem with your kind is that you cannot handle motions or move
around information to bring about interesting linkages.For
instance,the generalised dynamics of rotating bodies with a viscous
composition generate spherical deviation for different Equatorial
speeds -

http://www.jpl.nasa.gov/releases/200..._2001_150.html

It follows that all rotating celestial objects with a viscous
composition display a clear correlation between maximum Equatorial
speed,differential rotation and spherical deviation up to an including
the 40 km spherical deviation of the Earth.The differential rotation
of the homogeneous material in direct contact with the fractured
surface crust is the driving force for crustal evolution off the
entire length of the Mid Atlantic ridge and the mechanism for crustal
motion and the generation of surface geological features and events.

http://pubs.usgs.gov/gip/dynamic/gra...ntic_ridge.gif

I just use observed variations generated by stellar dynamics and apply
the principles to the Earth's rotating interior by way of looking at
the Mid Atlantic ridge -

http://pubs.usgs.gov/gip/dynamic/gra...ntic_ridge.gif

http://www.dkimages.com/discover/pre...2/60018786.JPG

While you and the unimaginative languish with thermal convection cells
which require no association with planetary shape or rotational
dynamics, I have been enjoying the fruits of rotational dynamics for
years as applied to geological features such as the symmetry of
crustal generation of the entire length of the ridge.Maybe it is just
sheer dullness that cannot link rotational dynamics with evolutionary
geology but then again,you have your 'polytrope' to think about,great
word but says nothing about the fact the the Sun is actually rotating
and the composition with its particular viscosity and density behave
in a specific way.



Of course,what is observed as generalised principles for rotating
viscous bodies,be they stars or planets,in terms of the triumvirate of
correlations between max Equatorial speed,differential rotation and
spherical deviation

In article ,
"Mike Dworetsky" writes:
Real stars are not polytropes, in part because the equation of
state may involve degenerate gases rather than perfect gases.

The major reason, I think, is that composition is not in general
constant with radius. Nuclear burning products (mostly helium at
first) generally accumulate near the center, raising the mean
molecular weight there. I'd expect fully convective stars to be very
close to polytropes.

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
(Please email your reply if you want to be sure I see it; include a
valid Reply-To address to receive an acknowledgement. Commercial
email may be sent to your ISP.)

"Steve Willner" wrote in message
...
In article ,
"Mike Dworetsky" writes:
Real stars are not polytropes, in part because the equation of
state may involve degenerate gases rather than perfect gases.

The major reason, I think, is that composition is not in general
constant with radius. Nuclear burning products (mostly helium at
first) generally accumulate near the center, raising the mean
molecular weight there. I'd expect fully convective stars to be very
close to polytropes.

--
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA
(Please email your reply if you want to be sure I see it; include a
valid Reply-To address to receive an acknowledgement. Commercial
email may be sent to your ISP.)

Yes, that too. In fact, transitions from convective to radiative energy
transport also lead to "non-polytrope" real models. And so do degeneracy
and composition changes as evolution progresses.

Stars like the Sun have radiative cores and convective envelopes; further up
the main sequence, stars have convective cores and radiative envelopes.

But polytropes can give a good first-order feel for the generalities of
stellar structure--order of magnitude central temperature and pressure,
main-sequence radius vs mass, etc. This is one reason why they are still
taught in astrophysics courses. Or at least, in some courses.

--
Mike Dworetsky

(Remove pants sp*mbl*ck to reply)