Almost all astronomy graduate students are fully supported financially, either by graduate assistantships or by fellowships (rare exceptions are students who have the opportunity to move into their new jobs while still writing the final stages of their dissertations). The most common kind of financial support is a graduate assistantship, though some students are supported by NASA or NSF fellowships.
During the summer months students can supplement their income as follows:
One $5000 scholarship is offered each year by the ARCS foundation:
The following page lists some other potential funding sources. Please email the graduate chair with any additional suggestions.