I've got a couple of shelves that were manufactured to 120cm in length, which is slightly less than 48" (47.25"). Unfortunately, I discovered that the desired location has stud spacing of 24" rather than 16". This means that if I hang the shelf using two brackets placed on the studs, I'm going to have an overhang of around 11.625" on either side.
Is that too much overhang? Would it be better to use drywall anchors to space one or both (or more?) of the brackets out farther?
The recommendations I've found online vary as to how much overhang is safe, most suggesting no more than 6" but I've also seen 12". My gut feeling is it would be ok as long as I didn't put heavy objects on the ends of the shelves, but as a DIY noob I don't trust my gut.
Edit: The shelves are 1" particle board and weigh 10 pounds. They will be used for a reasonably light load - display objects, small potted plants and a few books.