Ephemeralist , ephemerologist ,
A person who studies printed ephemera is called an ephemeraologist. They specialize in the collection, analysis, and preservation of paper-based materials such as posters, flyers, tickets, and other items of short-lived significance.
You call someone that studies metal a metallurgist.
A physicist.
a person who studies planets is a planetologist.
There is no special name for someone who studies Hebrew.
An Anthropologist.
malacologist
euclidist
Gemologists
psychologist
A numismatist.
A Zoologist
a meteorologist.