Question:
What is the difference between and amateur and a professional astronomer?
Answer:
Traditionally, Amateur Astronomy is recent, not more than 100 years old. It began by having as "members" people from the general public with any training (or even without it) who were dedicated to building telescopes and promoting joint parties for the observation of astronomical objects by them. In the last 20-30 years, Amateur Astronomy began to have cheap enough telescopes available that they "discouraged" the hours dedicated to their construction. In addition, detectors and other (almost) professional quality equipment are also sold at affordable prices. Thus, nowadays the Amateurs can contribute to Science due to the amount of hours they have available and the good equipment they have. However, the main difference with regards to a professional has to do with training: rarely does an amateur know Astronomy in depth enough to carry out, for example, training actions for teachers and students in an error-free way. Still, not knowing the scientific method "from the inside", it is not possible for them, on their own, to produce any relevant scientific result: they are not able to publish in an international journal. However, when associated with professionals, success is (almost) guaranteed and there are examples, even in our country (e.g. Madeira), of collaborations between amateurs and professionals that resulted in articles published in an international journal.