Transcript The Sun - Mid-Pacific Institute

The Sun
By: Tori and Caitlin
SHINNING STAR

The Sun is the star
at the center of the
Solar System. It
has a diameter of
about
1,392,000 km,
about 109 times
that of Earth, and
its mass accounts
for about 99.86% of
the total mass of
the Solar System.
Composition

About three quarters
of the Sun's mass
consists of
hydrogen, while the
rest is mostly helium.
Less than 2%
consists of heavier
elements, including
oxygen, carbon,
neon, iron, and
others.
Characteristics

As the Sun consists of a plasma and is
not solid, it rotates faster at its equator
than at its poles. This behavior is
known as differential rotation, and is
caused by convection in the Sun and
the movement of mass, due to steep
temperature gradients from the core
outwards.
Formation

The formation of the
Sun may have been
triggered by
shockwaves from
one or more nearby
supernovae.This is
suggested by a high
abundance of heavy
elements in the Solar
System, such as
gold and uranium.
Boundary

The Sun does not
have a definite
boundary as rocky
planets do, and in
its outer parts the
density of its gases
drops exponentially
with increasing
distance from its
center.
The Core

The core of the Sun is
considered to extend
from the center to
about 20-25% of the
solar radius. It has a
density of up to
150 g/cm3(about 150
times the density of
water) and a
temperature of close to
13.6 million kelvin (K).
Radiative Zone

From about 0.25 to
about 0.7 solar radii,
solar material is hot
and dense enough
that thermal radiation
is sufficient to
transfer the intense
heat of the core
outward.
Convective Zone

In the Sun's outer layer,
from its surface down to
approximately
200,000 km (or 70% of
the solar radius), the
solar plasma is not
dense enough or hot
enough to transfer the
thermal energy of the
interior outward through
radiation.
Photosphere

The visible surface of
the Sun, the
photosphere, is the
layer below which the
Sun becomes opaque
to visible light. The
change in opacity is
due to the decreasing
amount of H ions, which
absorb visible light
easily.
Atmosphere

The parts of the Sun above the
photosphere are referred to collectively
as the solar atmosphere. Which is
comprised of five principal zones: the
temperature minimum, the
chromosphere, the transition region,
the corona, and the heliosphere.
Magnetic Field

The Sun is a
magnetically active
star. It supports a
strong, changing
magnetic field that
varies year-to-year
and reverses
direction about every
eleven years around
solar maximum.
Summary



The Sun is the star at the center
of the Solar System.
About three quarters of the Sun's mass
consists of hydrogen.
The formation of the Sun may have
been triggered by shockwaves from
one or more nearby supernovae.
Works Cited
"Sun: Formation, Evolution, Orbit & Characteristics | Solar System, Space,
Sunspots & Solar Nebula | Space.com." Space, NASA Information & News |
Outer Space Flight Videos & Pictures | Astronomy, Solar System Images |
Space.com. Web. 11 Jan. 2011. <http://www.space.com/58-the-sun-formationfacts-and-characteristics.html>.
"The Sun L Sun Facts and Images." The Nine Planets Solar System Tour. Web.
11 Jan. 2011. <http://nineplanets.org/sol.html>.
"Sun, Sun Information, Facts, News, Photos -- National Geographic." Science and
Space Facts, Science and Space, Human Body, Health, Earth, Human
Disease - National Geographic. Web. 11 Jan. 2011.
<http://science.nationalgeographic.com/science/space/solar-system/sunarticle.html>.
"Sun." Views of the Solar System. Web. 11 Jan. 2011.
<http://www.solarviews.com/eng/sun.htm>.