vertical alignment of custom symbol

Question

I defined the following command

\newcommand{\bigast}{\mathop{\Huge \mathlarger{\mathlarger{*}}}}

Unfortunately, its vertical alignment is a bit too high

I tried fixing it with \raisebox{} but couldn't make it work. Any ideas how to correct its vertical alignment?

Thanks for any help!

Answer 1

From How are big operators defined?, this makes the \ast occupy the same vertical footprint as \sum, which we know is well behaved.

I show two implementations, one that retains the \textstyle size always, and the other that grows in \displaystyle.

\documentclass{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\DeclareMathOperator*{\foo}{\scalerel*{\ast}{\sum}}
\DeclareMathOperator*{\barr}{\scalerel*{\ast}{\textstyle\sum}}
\usepackage{scalerel}
\begin{document}
[
\foo_{i=3}^{6}(f^2(i))
]
This is inline: (\foo_{i=3}^{6}(f^2(i)) )
[
\barr_{i=3}^{6}(f^2(i))
]
This is inline: (\barr_{i=3}^{6}(f^2(i)) )
\end{document}