astronomy

1. The Milky Way Galaxy
Dr. Robert E. Nahory

2. The Milky Way Galaxy
The Milky Way galaxy is a spiral galaxy
of at least 200,000,000,000 stars.
Our Sun lies within the Orion Arm about 26 000 light years
from the center of the galaxy.

3. The Milky Way galaxy is a spiral galaxy of about 200,000,000,000 stars.
Our Sun lies within the Orion Arm about 26,000 light years from the
center.

4. The Sun is located in the Orion Arm

5. The Milky Way is surrounded by several dwarf galaxies,
typically containing a few tens of millions of stars

6. The Sun
The Milky Way Galaxy – from above
The Sun is in the Orion Arm, about 26,000 light-years from the center.
The whole galaxy is more than 90,000 light-years across.

7. The Milky Way Galaxy – Properties
Properties of the Milky Way
Diameter of the Galaxy 90 000 light years
Classification of the Galaxy SBbc
Number of stars in the Galaxy 200 billion
Mass of the Galaxy 1 trillion solar masses
Length of the central bar 25 000 light years
Distance of the Sun from the center 26 000 light years
Thickness of the Galaxy at the Sun 2000 light years
Velocity of Sun around the Galaxy 220 km/s
Orbital period of Sun around the
225 million years
center of the Galaxy
This is a list of some of the main parameters of the Milky Way Galaxy.
Most of these numbers are approximate.
Galaxies do not have precise boundaries – the stars slowly become less plentiful
as you move away from the galaxy.

8. Galaxies that look like the Milky Way Galaxy

9. The Milky Way Galaxy - as we see it
An all-sky plot of the 25000 brightest stars
shows how these stars are concentrated along the Milky Way.

10. The Milky Way Galaxy - as we see it
Infrared view of the Milky Way Galaxy.
Dark regions in this image are huge clouds of galactic dust.