The number of professional astronomers in the United States is actually quite small.

Mitchell was the first American woman to work as a professional astronomer.

The professional astronomers then try to make scientific sense out of the data.

Both amateur and professional astronomers have begun to use this technique.

Less than two percent of professional American astronomers consider the subject even worth showing an interest in.

These are used by professional astronomers to conduct a wide range of astronomical research.

But in trying to write an account that will satisfy professional astronomers, he has probably lost many general readers.

Over the last 100 years, many local amateur and professional astronomers have made use of the telescope.

For the most part, these were too difficult to be used by anyone except professional astronomers.

The goal is to have the best mix of professional astronomers that can be found.