OK, 
seems to be a member of FA, but what does the ★ stand for?
Klaus (sesom ★)
It seems wrong to disagree with a staff member in the referred-to thread but it appears that the black star indicated that one is logged into one’s account. I can turn the star by my name off by logging off and on by logging on.
I read the mentioned thread some hours ago, but was none the wiser afterwards. The given explanations for the ★ seemed not correct for me.
That seems to be plausible. Tnx!
Klaus