Transcript Guided Notes about the Sun

Guided Notes about the Sun
1. The Sun contains more than
99 percent of all the mass in
the solar system. The Sun’s
mass controls the motions of
the planets and other
objects.
2. The solar interior is gaseous
throughout because of its high
temperature. The gases are
completely ionized, meaning
that they are composed only of
atomic nuclei and electrons.
This state of matter is called
plasma.
3. The lowest level of the Sun’s
atmosphere is the photosphere.
This is the visible surface of the
Sun. Most of the light emitted
by the Sun comes from this
layer.
4. Above the photosphere is the
chromosphere, which is normally
visible only during a solar eclipse
when the photosphere is blocked.
The chromosphere appears red
because it emits most strongly in a
narrow band of red wavelengths.
5. The top layer of the Sun’s
atmosphere is the corona, which
extends several million kilometers
from the top of the chromosphere.
The corona is so dim that it can
only been seen when the
photosphere is blocked, such as
during an eclipse.
6. Gas from the corona of the Sun flows
outward at high speeds and forms the
solar wind. The charged particles are
deflected by the Earth’s magnetic field
and form 2 huge rings called the Van
Allen belts. The particles collide with
gases in the Earth’s atmosphere,
causing them to give off light that we
see as the aurora.
7.
The Sun’s magnetic field
disturbs the solar
atmosphere periodically and
causes new features known
as sunspots.
8.
Sunspots appear darker
than the surrounding areas
on the Sun because they are
cooler. Sunspots typically
last two months.
9. Solar flares are violent
eruptions of particles and
radiation from the surface of
the Sun. Often, the released
particles escape the surface of
the Sun in the solar wind and
Earth gets bombarded with
particles a few days later.
10.Within the core of the Sun,
where the pressure and
temperature are extremely
high, fusion occurs. Fusion is
the combining of lightweight
nuclei, such as hydrogen, into
heavier nuclei.
11.In the core of the Sun, helium
is a product of the process in
which hydrogen nuclei fuse.
The mass lost in the fusion of
hydrogen to helium is converted
to energy, which powers the
Sun.
12. The Sun consists of about 70.4 percent
hydrogen, and about 28 percent helium,
measured by mass, along with a small
amount of other elements. The Sun’s
composition represents that of the
galaxy as a whole. Hydrogen and helium
are the predominant gases in stars, as
well as in the entire universe. All other
elements are in very small proportions
compared to hydrogen and helium.