SkyTools works primarily on multiple star systems, not individual pairs.

[theskyhound]

I am sorry but you are mistaken. Some people believe that East longitudes are standard, and indeed we often see longitudes written as positive toward the east (as measured from Greenwich). But in fact, longitudes can be measured in either direction, and the only real standard is that you must state which direction it is being measured in.

The Wiki page provides a longitude that is measured toward the East (see the "E" after the number). So it is positive in Europe.

SkyTools 3 asks for longitudes measured to the west, which means that they are positive in the western hemisphere and negative in Europe. So it is a negative number.