What does the $O^*$ notation mean?

Question

I'm recently reading some papers on the maximum independent set problem, all the algorithms' time complexity is donated by $O^*()$ notation, like $O^*(1.0836^n)$. One paper says "the $O^*$notation suppresses polynomial factors in the input size." I'm a little bit confused and couldn't find helpful materials on the Internet. Could you guys clarify it for me? Any related literature or links will be appreciated.

Thanks in advance!