How long does it usually take to get a phd in astronomy?

Answer 1

PhDs in the sciences usually take four or five years. It usually takes longer to get a PhD in the arts.

Students usually take two or more years of coursework with a written preliminary exam after the second year. There is ausually an oral preliminary exam in the third year. A dissertation will usually take one to three years to write. At most schools, you defend the dissertation to your committee before being granted your degree.

Answer 2

as long as it would take to get a PhD in anything else, 8 years if you are taking and passing a F/T students regular class load (12 Credits)