Milky Way Galaxy

A barred spiral galaxy (SBc) that is our home in the cosmos.

Size: 110 000 light years across

Age: At least 13.6 billion years.

Number of stars: 300 billion

Arms: Four main spiral arms.

Nucleus: Contains a 2 million solar mass black hole in the center (Sgr A*).

Sun’s position: Located within the disk, 40 light years above the plane, 27 000 light years from the centre, within the Orion Arm (a.k.a. Local Arm).

Our orbit: The Sun and our solar system take 240 million years to make one orbit around the centre of the Milky Way, at a speed of 250 km/s (900 000 km/h).

Highlights:

• Member of the Local Group (along with 48 other galaxies) which in turn is part of the Virgo Supercluster, which is part of the Laniakea Supercluster.
• Our Milky Way is one of 200 billion galaxies in the Universe.
• We see the centre of our Galaxy in the direction of Sagitarius as a bright patch known as the Great Sagitarius Star Cloud.