Astronomer .
a person that studies gems is called a gemologist.
A person who studies animals is called a zoologist.
A person who studies the earth is called a geologist.
A Herpetologist (I think I spelled it correctly)
Well, It's Simple: Mammalogist. -Cassidy! :D
Astronomy, the person who studies them is an Astronomer
The proper name for the study of stars is astronomy. A person who studies stars is an astronomer.
I agree with the above comments. But if you want to get really fancy, you could go with Selenographer (a person who charts the surface of the Moon) or Selenologer (a person who studies the Moon).
These people are called Astronomers. Look it up in wikipedia if you want more information.
a person that studies gems is called a gemologist.
The Person Who studies about mamals , he is called mamalogist....
A person who studies animals is called a zoologist.
They are called an astronomer.
A person who studies physics is called a physicist, a person who studies chemistry is called a chemist, and a person who studies biology is called a biologist.
A person who studies the mind and behavior is called a psychologist.
A person who studies or writes history is called a historian.
Alligators of reptiles, so one who studies them is called a herpetologist.