The article says the 17-point star is on a monument to Gauss in his home town of Brunswick Germany, not on his headstone.

An image search for "gauss monument brunswick germany" on Duck Duck Go includes a picture of the 17-point star at this link:

https://www.braunschweig.de/leben/stadtportraet/stadtteile/n...

I can't go to it to confirm because we are blocked from going to foreign links at my work place. It looks like the star is on the left side of the monument near his right foot.