[![part of a circle of fifths showing the symbol][1]][1]


  [1]: https://i.sstatic.net/rjrWi.png

I found this neat tool online to save me having to draw out a circle of fifths myself, and clicking on the key you are writing in even shows you the chord 'family'. Since I'm writing in F minor I clicked on that but I'm unfamiliar with the small degree-like symbol that came up next to the ii on Gm. What does it mean?
Thanks in advance.