u/After-Yam-7424

Given that someone who studies the physics of celestial bodies is usually called an “astrophysicist,” how is the term “astronomer” actually used?

Is it reserved for professionals with formal academic training (PhD), or can it also apply to amateurs or people deeply involved in the field, even if they come from another discipline?

For example:

1. Bachelor’s degree in Physics + PhD in Astrophysics >>> “astrophysicist” (and also “astronomer”?)

2. Someone from another field (e.g., Archaeology) who collaborates on research related to astronomy >>> could they be called an “astronomer”?

3. A serious amateur involved in observation and study of the sky >>> would it be valid for them to call themselves an “astronomer”?

How is this term used in practice?