The document discusses the stars and galaxies in the universe. It begins by describing the sun as the closest star to Earth and the center of our solar system. It is fueled by nuclear fusion and provides light and heat for life. The document then covers the various types of stars including white dwarfs, neutron stars, giants, and supergiants. It explains that stars are formed in nebulae from collapsing gas and dust clouds. As stars age, they eventually die and become white dwarfs, neutron stars, or black holes depending on their original mass. Galaxies are groups of stars held together by gravity, and come in spiral, elliptical, and irregular shapes. The Milky Way is a spiral galaxy containing around 200 billion
2. THE SUN
The Sun is the closest star to Earth and is the center of
our solar system. A giant, spinning ball of very hot gas,
the Sun is fueled by nuclear fusion reactions. The light
from the Sun heats our world and makes life possible.
The Sun is also an active star that displays sunspots,
solar flares, erupting prominences, and coronal mass
ejections. These phenomena impact our near-Earth
space environment and determine our "space weather."
3. Charateristics of the Sun
Size: 1 392 000 km in diameter
Mass: 1.98 x 10³° kg
Density: 1400kg/m³
Surface Temperature:5500 °C–
6000 °C
6. The Various Types of Stars
Stars are classify according to its size,
brightness, surface temperature and colour.
There are four main groups of stars, namely
-White dwarf
-Neutron stars
-Giants
-Super Giants
11. The Formation of Stars
Stars are formed within large clusters of dust
and gases called as nebulae.
Due to the force of gravity nebula collapses and
spin.
The spinning clouds pull in more hydrogen gas
over millions of years.
Collisions occurred between nebula and
hydrogen atoms.
Hydrogen atoms combine to form helium atoms,
releasing a large amount of heat and light.
12. The Death of Stars
The lifespan of Star is determined by the
original mass of the Star.
The Star will become either a white dwarf,
neutron Star or black hole when it dies.
15. THE GALAXIES
A Galaxy is a group of stars held together
by gravity.
There are billions of stars in a Galaxy.
The main three types of Galaxies are
- Spiral Galaxy
- Elliptical
- Irregular
19. The Milky Way
It is the name of Galaxy.
It has spiral shape.
It contains 200 billions stars.
Sun is one of the star in Milky way.
20. THE UNIVERSE
The Universe contains billions of galaxies
with each galaxy containing billions of
stars.
Universe is always evolving. Everything
that exits in the universe is not permenant.
New stars are being born while existing
stars will eventually die.
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21. THE UNIVERSE
The Universe contains billions of galaxies
with each galaxy containing billions of
stars.
Universe is always evolving. Everything
that exits in the universe is not permenant.
New stars are being born while existing
stars will eventually die.