Incidentally the Canon Rebel has two features that are not helpful for astrophotography.

1 - Its a CMOS chip, not a CCD at all. In low light a CMOS is not particularly good

2 - Its a 10 Mpixel chip. More pixels = less light sensitivity. You lose signal/gain noise by having too many bins. Look at the dedicated astro CCD cameras - 1280 x 1048 is a huge matrix, most have even fewer.