Question:
Who was the chair of Paris Observatory, PSL University in Dec, 2018?

Context:
 César-François Cassini de Thury is the chair of Paris Observatory, PSL University from Jan, 1756 to Jan, 1784. 
 Fabienne Casoli is the chair of Paris Observatory, PSL University from Mar, 2020 to Dec, 2022. 
 Michel Combes is the chair of Paris Observatory, PSL University from Jan, 1991 to Jan, 1999. 
 Giovanni Domenico Cassini is the chair of Paris Observatory, PSL University from Jan, 1671 to Jan, 1712. 
 Claude Catala is the chair of Paris Observatory, PSL University from Jan, 2011 to Mar, 2020. 
 Dominique, comte de Cassini is the chair of Paris Observatory, PSL University from Jan, 1784 to Jan, 1845. 
 Jacques Cassini is the chair of Paris Observatory, PSL University from Jan, 1712 to Jan, 1756. 
 Daniel Egret is the chair of Paris Observatory, PSL University from Jan, 2003 to Jan, 2011.

Answer:
Claude Catala