Huge gravitationally bound collections of stars with very little else between them.

Not that

Triangulum Galaxy M33

The small and large magellanic clouds (the SMC and the LMC)

Andromeda Galaxy M31

Large Milky band stretching across the sky

We are looking into the plain of our galaxy from one of its spiral arms

Not that

Not that

A giant disk shaped Catherine Wheel rotating around a central bulge

In the Winter Triangle

In a line from Cassiopeia to Cygnus

The galactic centre lies in Sagittarius

In the Summer Triangle

The halo - Young stars, gas and dust - Four major spiral arms - Is 1-2kpc thick - 30kpc in diameter

The Halo - Globular clusters (dense groups of relatively old stars) Spherically distributed along the galactic centre

The disk - Globular clusters (dense groups of relatively old stars) Spherically distributed along the galactic centre

The disk - Young stars, gas and dust - Four major spiral arms - Is 1-2kpc thick - 30kpc in diameter

A bulge surrounding the nucleus (black hole)

Floating with the Globular Clusters

10kpc from nucleus in a spiral arm

In One of the spiral arms

In the Bulge

5kpc from nucleus in a spiral arm

Huge clouds of gas and dust that can block light

Not that!

None of the above

Psychic Seeing

Microwave EMR (wavelength =21cm, frequency = 1420mHz) can be seen by radio telescopes on Earth. This wavelength is given off by hydrogen.

Doppler shifts in the wavelengths - We can work out how the galaxy is rotating