Stars

SPACE

BLACK HOLES
There are many popular myths concerning black holes, Hollywood makes up mostly what we know about them. Television and movies have
portrayed them as time-traveling tunnels to another dimension,
cosmic vacuum cleaners sucking up everything in sight, and so
on. It can be said that black holes are really just the evolutionary
end point of massive stars. But somehow, this simple
explanation makes them no easier to understand or less mysterious.

NEBULA
Gas, dust and debris from star explosions and around star forming regions are called nebulae. A nebula can reflect light or absorb light.

The Great Orion Nebula in the sword of Orion Stars are being formed in the cloud of gas and dust.
The Eagle Nebula in the constellation Aquila. You can see the darker clouds in the center look like a diving eagle.
This emission nebula glows red because of hot hydrogen atoms.

GALAXIES
A galaxy is like an island in space made up of gas, dust and millions of stars. Our own galaxy, the Milky Way, includes about a trillion (a thousand billion) stars in a disk shape. The Andromeda Galaxy and two companion galaxies. It is over 2.4 million light-years away from us.


HOT DARK MATTER AND COLD DARK MATTER
Discussions of dark matter typically consider two extremes
-Hot Dark Matter
-Cold Dark Matter

Hot dark matter is composed of particles that have zero or near-zero mass.

Cold dark matter is composed of objects sufficiently massive that they move at sub-relativistic velocities.

PULSARS
Pulsars are rotating neutron stars. And pulsars appear to pulse because they rotate

QUASAR
Quasar is a very energetic and distant galaxy with an active galactic nucleus.

TYPES OR STARS

Black Dwarf
It is the remains of a dead white dwarf star after its heat is radiated into space.

Black Hole
It is what remains of a super collapsed star, whose gravitational pull is so great that no light can escape.

Brown Dwarf
It is a star whose mass is too small to have fusion occur at its core.

Neutron Star
It is the tiniest star, having collapsed into a super dense state. It is thought to have formed when a large star exploded as a supernova.

Nova
It is a star that brightens suddenly, lasts a few days, fades away, and returns to its normal state.

Red Giant
It is a large, bright star, many times larger than the Sun, but with a cool surface. It is believed to be in the end stage of its life cycle.