Is there a "surface" of the Sun?

hello, world\n

recently I've been pondering the question if there is something like a
"surface" of the Sun. Let me try to define the term surface more
precisely: Consider a graph with the density over distance from center
("density profile"). Considering a fixed location on Earth there would
be a very localized decrease from about 1000kg/m^3 to 1kg/m^3 (ocean
surface to atmosphere) within only a few meters near what we call the
radius of the Earth. The decrease in density is even larger if at the
fixed point there is a transition solid-atmosphere.

Now for the Sun, if at some fixed point we ignore effects due to medium
scale rising/receding fluids, what would the density profile of the Sun
look like? I don't expect a factor 1000 decrease in density over a few
meters, but what exactly would the profile look like?

Regards,

Jens
--
Jens Schweikhardt http://www.schweikhardt.net/
SIGSIG -- signature too long (core dumped)

On 11/09/2011 12:18, Jens Schweikhardt wrote:
hello, world\n

recently I've been pondering the question if there is something like a
"surface" of the Sun. Let me try to define the term surface more
precisely: Consider a graph with the density over distance from center
("density profile"). Considering a fixed location on Earth there would
be a very localized decrease from about 1000kg/m^3 to 1kg/m^3 (ocean
surface to atmosphere) within only a few meters near what we call the
radius of the Earth. The decrease in density is even larger if at the
fixed point there is a transition solid-atmosphere.

Now for the Sun, if at some fixed point we ignore effects due to medium
scale rising/receding fluids, what would the density profile of the Sun
look like? I don't expect a factor 1000 decrease in density over a few
meters, but what exactly would the profile look like?

Regards,

Jens

The generally accepted definition for the 'surface' of the sun is the
Photosphere; that region where the optical depth is about 70% - i.e.
there is a 70% chance that a photon emitted at that position will escape.

There is a plot of 'density'on the right of the Wikipedia page; though
it's a multi-axis plot, which I've only had a quick look at

Wiki Page
http://en.wikipedia.org/wiki/Photosphere

Density plot
http://history.nasa.gov/SP-402/p2.htm
NB that the Y axis is height and density is plotted on a log axis.