Counting Nearby Stars

In my previous post, I casually stated that there are 61 stars in the region within 5 parsecs of the Sun -- at least according to the Gliese Catalog of Nearby Stars. I did not state where you could get that information for yourself. This short post describes how to figure this out for yourself. Here is my approach:

• Get a copy of the Gliese Catalog here.
• Look in the readme file here to understand the document format.
• Many of these stars have common names that you can find .
• Analyze the text file for the nearby stars in Excel like I did here.

My quick and dirty analysis shows that there are 61 stars within 5 parsecs of the Sun. I put together an Excel table but it is my second favorite software tool -- Mathcad is my favorite. I did add a couple of columns to the original Gliese columns: (1) a column of common names, and (2) the distances to the stars in light-years. The Gliese catalog just gives the milliarcseconds of parallax and I needed to convert the milliarcseconds to light-years using the following formula.

Here is the table I put together. I should note that new stars have been discovered since the Gliese table was put together (example). This is just a rough order of magnitude calculation (Fermi problem) and the results are good enough for what I am doing here.