The most important factor in determining your course of study will be whether or not you eventually wish to enter graduate school in astronomy. If you do, the students you will be competing with for admission will mostly have undergraduate degrees in physics. Modern astronomy is a branch of graduate level physics. To be a successful researcher in astronomy, there is no escaping the need for a thorough grounding in the fundamentals of physics.
The Pre-Professional Program Leading to Graduate Research
If you plan to go to graduate school in astronomy, you will want to select a program heavy in undergraduate physics and math - a program, in fact, very similar to the BS plan in Physics. Only in this way will you be competitive as far as graduate school admission and performance is concerned. The astronomy major requirement will be fulfilled easily, in that you will have to take considerably more than this formal minimum requirement to gain admission to a good graduate school, in fact, a total program of at least 130 hours as an undergraduate will probably be required. As far as the minor is concerned, you would be covering it by taking extra physics courses.
The General Program
Students whose interests are not directed to PhD level research, however, can look into this option and design for themselves a wide variety of programs in astronomy and astronomy-related courses of study. Some examples discussed earlier were history plus astronomy, philosophy plus astronomy, journalism plus astronomy (orienting courses towards science writing), communications plus astronomy (appropriate for planetarium work), education plus astronomy (secondary teaching ) etc. Such programs will not have the same compelling need for as much upper-division physics as the pre-professional program discussed above, and can be flexibly designed in conjunction with advising from both the astronomy and related departments.