How to add equal contribution asterisk beside author names?

[hmishfaq]

Hi, I am trying to add asterisk for equal contribution beside author names like you did in the first poster here: https://anishathalye.com/gemini-a-modern-beamerposter-theme/. How did you do this?

[anishathalye]

Here is the author line from that poster:

\author{Anish Athalye$^*$ \inst{1} \and Nicholas Carlini$^*$ \inst{2} \and David Wagner \inst{2}}

\institute[shortinst]{\inst{1} MIT CSAIL \samelineand \inst{2} UC Berkeley}