Professional astronomy is very competitive and complex--not just star gazing. A full professor will make 90k+ a year, depending on the university/institution. This is a good living, but not "striking it rich" by any means. Assistant professors and other Phd positions might pay 50k-80k.
These jobs are very, very rare. If you are very smart, hard working, a little lucky,and go to a top tier school (think Harvard), you might get one.
This is the situation in many fields for PhDs. There are more graduates than positions. However, I wouldn't discount getting an astronomy degree if that is what you love. People who get their education simply to get a job often end up miserable and unsatisfied in their line of work. And they have a degree that helped them get that way, when all is said and done. In short, they have nothing but a paycheck. Trust me on this: the thrill dies quickly.
On the other hand, if you pursue your passion, you will be driven, productive and happy through the process. You will spend years paying it off, but you would be doing this even if you did get a job in the field. Your education is a part of who you are. It shapes your worldview. It cannot be taken away. It WILL enrich your life in ways that are often unforseen.
I say go for it. A smart, well educated person can always find some sort of work to pay the bills. Smart, educated people are generally in demand. But what will you have if you pursue your father's dreams, and not yours?
Bitterness.
Fortune favors the brave.