In the following TeX file which is written based on elsarticle template, I want the second author (author2) be the corresponding author. I put the \corref instruction for author2 but when I run the code, the \ast symbol appears for both author2 and author3.
\documentclass[preprint,12pt]{elsarticle}
\usepackage{epsfig}
\usepackage{subcaption}
\captionsetup{compatibility=false}
%% The amssymb package provides various useful mathematical symbols
\usepackage{amssymb}
\usepackage{mathptmx}
\usepackage{amsmath}
\newtheorem{thm}{Theorem}
\newproof{pf}{Proof}
\DeclareMathOperator*{\argmin}{arg\,min}
\DeclareMathOperator{\sign}{sign}
\journal{X}
\begin{document}
\begin{frontmatter}
\title{The title of the paper are placed here}
\author{author1}
\ead{author1\_ [email protected]}
\author{author2\corref{cor}}
\ead{[email protected]}
\author{author3}
\ead{[email protected]}
\address{The affiliations and adresses}
\cortext[cor]{Corresponding author}
\begin{abstract}
%% Text of abstract
Some text are presented here.
\end{abstract}
\begin{keyword}
%% keywords here, in the form: keyword \sep keyword
Keyword1 \sep Keyword2 \sep Keyword3
\end{keyword}
\end{frontmatter}
\section{Introduction}
\label{intro}
Introduction goes here.
\bibliographystyle{elsarticle-num}
\bibliography{Bibiliography}
\end{document}