Let's plot the positions of nearby young stars and star clusters:
Indication of spiral structure -- we live near the Orion-Cygnus arm.
| If we look at stars in the disk, we find that
they are not scattered smoothly throughout the disk.
Let's plot the positions of nearby young stars and star clusters: Indication of spiral structure -- we live near the Orion-Cygnus arm. |
|
 |
We see it more dramatically when we look at other galaxies,
and it's most noticable in blue light than in red.
What is this telling us? |