Specific IC 2118 information

This will be fleshed out more in time.

Right now, all I have is the following:

Finding the cluster members

Spitzer is so sensitive that it easily sees things at the far reaches of the Universe with only a few seconds' integration. When studying clusters of stars, not just with Spitzer, one of the first major goals is to figure out which objects are truly cluster members and which are not. This pdf file has a discussion of how to find members of young clusters.