The ornamental design for a starryskyprojectorlamp, as shown and described.
FIG. 1 is a front perspective view of a starry sky projector lamp showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a left view thereof;
FIG. 4 is a right view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a top view thereof;
FIG. 7 is a bottom view thereof; and,
FIG. 8 is a rear perspective view thereof.
The broken lines shown in the drawings are included for the purpose of illustrating portions of the starry sky projector lamp, and form no part of the claimed design.