Milky Way

Milky Way, catch taken in space simulator
SpaceEngine.

Milky Way is a barred spiral galaxy (Class SBc), it's the second largest galaxy in the local group and is the galaxy that contains our Solar System.

It's formed by clouds of gas, cosmic dust, dark matter, energy, planets and stars all these structures are linked by the existence of gravity and they revolve around the center of the galaxy

It has a mass of 0.8–1.5×10^12 M☉, a diameter of  126090 light-years and contains 270 billions of stars approximately, also it has 10668 Clusters and 12410 Nebulae.

Parts of the Milky Way are: Halo, Disk and Bugle.

Halo: It's made up mainly of Dark matter, Clusters and older stars.
Disk: The disk is composed of 8 spiral arms, they have most of the nebula, gas and dust in the galaxy and the younger stars.

Bugle: It's the central group of stars and contains the supermassive Black Hole Sagittarius A* (Sgr A*)

(If you want to know more about the supermassive black hole at the center of the galaxy press here).

The Black Hole at the center of the Galaxy

Milky Way is a spiral galaxy, it is formed by clouds of gas, cosmic dust, dark matter, energy, planets and stars all these structures are linked by the existence of gravity and they revolve around the center of the galaxy, also The Sun revolves around the center of the galaxy at a speed of 220 Km/s.

If the structures that exist in the galaxy revolve around galactic center then what about the center?

Catch of the accretion disk of Sagittarius A * taken from 

the space simulator spaceengine.

In the center is a supermassive black hole its name is Sagittarius A* (Sgr A*).
Sgr A* has a mass of 4.31*10 (Exponent 6) Solar masses, that is to say, 4 million times the mass of The Sun. it has never been seen (because it doesn't emit radiation in the form of light), but it exist by the mysterious movement of the nearest stars, and of all the Galaxy.

In the Center of the galaxy there are many stars, and emits large amounts of radiation.

The movement of the accretion disk of Sagittarius A * and its stars, along with the black hole recorded from spaceengine looks like this: