We hung new drywall on our kitchen ceiling and had a pro tape it. After I rolled on a coat of primer and one of ceiling paint, I noticed an area where he and I both missed sanding. It is a section where he feathered out the joint compound along a metal corner bead, attached where a stairwell breaks through the ceiling. I already plan to apply a second coat to the ceiling. How best to smooth out or hide this ridge that shows when light shines across the ceiling?

Should I try to sand it smooth, or apply a little more joint compound, or what? Thanks.