Station Info :: Space
Solar System :: Layers
Layers Of Sun
has many different layers that describe its structure.
The core is the innermost
layer of the sun and it is a source for all the Sun's
energy. The material in the core is firmly attached and has
very high temperature, which is about 15 million degrees Kelvin.
In the core the intense heat destroys the internal structure
of an atom and therefore all atoms are broken down into their
constituent parts. An atom is composed of protons, electrons
and neutrons. Neutrons have no electric charge and so they
do not interact a lot with the surrounding medium. Thus neutrons
go away the core fairly and quickly. The protons, which have
positive electric charge, and the electrons, which have negative
electric charge, remain in the core and force the reactions
which fuel the Sun. The charge neutral material of protons
and electrons that makes up the core is called plasma. The
high temperature provides the protons and electrons with a
great amount of thermal energy and therefore they moved pretty
quickly and they combine with the high density of the plasma,
causes the particles to continuously slam into one another
creating nuclear reactions. It is the fusion, or slamming
together, of particular combinations of particles that provides
the energy source of the Sun.
The core is the innermost layer
of the sun and it is a source for all the Sun's
energy. Thermonuclear reactions takes place inside
the core ,thus hydrogen atoms are comnbined with
each other to make helium atoms and produces energy
which keeps the Sun in a state of equilibrium.Thus
this thermonuclear reaction is called nuclear
Once the energy is produced
in the core of the sun, it has to travel from
the solar center to the outer regions. Hence the
radiation zone provides an efficient means of
transferring energy near the core. The temperature
in the radiation zone of the sun is cooler than
the core. The material 0.2 to about 0.7 solar
radii is hot and dense enough that thermal radiation
is sufficient to transfer the intense heat of
the core outward. Heat is transferred by ions
of hydrogen and helium emitting photons, which
travel a brief distance before being re-absorbed
by other ions.
Ranging from 0.7 solar radii to 1.0 solar
radii, the material in the Sun is not that
much dense or hot to transfer the heat energy
from interior to outward. Hence, thermal convection
occurs as thermal columns carry hot material
to the surface (photosphere) of the Sun. As
soon as the material cools off at the surface,
it plunges backside downward to the base of
the convection zone, to obtain more heat from
the top of the radiative zone. Convective
exceed is thought to occur at the base of
the convection zone, moving turbulent down
flows into the outer layers of the radiative
The thermal columns in the convection
zone shape mark on the surface of the Sun, in
the form of the solar granulation and supergranulation.
The turbulent convection of this outer part of
the solar interior gives rise to a 'small-scale'
dynamo that produces magnetic north and south
poles all over the surface of the Sun.
Photosphere is the visible
surface of the Sun. Above the photosphere, sunlight is free
to disseminate into space and its energy escapes the Sun completely.
Sunlight has approximately a black-body spectrum that indicates
its temperature is about 6,000 K, interspersed with atomic
absorption lines from the tenuous layers above the photosphere.
The photosphere has a element density of about 1023/m3 (this
is about 1% of the particle density of Earth's
atmosphere at sea level). The parts of the Sun above the photosphere
are referred to collectively as the solar atmosphere. They
can be seen with telescopes across the electromagnetic spectrum,
from the visible light to gamma rays.
This a thin layer present above
the visible surface, which is about 2,000 km thick,
specifically dominated by a spectrum of emission
and absorption lines. It is called the chromosphere
from the Greek root chromos, meaning color, for
the reason that the chromosphere is visible as
a colored flash at the beginning and end of total
eclipses of the Sun.
The corona is the outer atmosphere
of the Sun, which is much larger in volume than the Sun itself.
The corona merges slickly with the solar wind so as to fill
the solar system and heliosphere. The low corona, which
is very close to the surface of the Sun, has a particle density
of 1011/m3 (Earth's atmosphere near sea level has a particle
density of about 2x1025/m3). The temperature of the corona
is several million degrees K.