I don't think there is a special name for that. You can use the more general term "astronomer".
A person who explores caves is called a spelunker or a caver.
An astronomer.
The person is called an explorer. The word means a person who explores an unfamiliar area.
They are simply called "galaxies which are part of a cluster".
Elliptical galaxies are sometime called dwarf galaxies.
A person who studies planets and galaxies is called an astronomer. Astronomers observe and analyze celestial bodies such as planets, stars, and galaxies to understand their composition, behavior, and evolution. They use telescopes and other instruments to gather data and make scientific discoveries about the universe.
HTt
They are called elliptical galaxies.
irregular galaxies
A person who studies space is called an astronomer. They observe and analyze celestial bodies such as planets, stars, and galaxies to better understand the universe.
A person from Russia who explores space is called a cosmonaut. Cosmonauts are trained astronauts who are part of the Russian space program and conduct missions to outer space.
A group of galaxies is called a cluster.