Rules: Locate some squares (each having the size 3×3) in the grid so that all stars are surrounded by squares. Some cells of the squares can be outside the grid, but the central cell should always be inside the grid. Squares cannot overlap each other, but they can share edges. There shouldn’t remain any star which is not surrounded by a square. Central cells of squares cannot overlap the stars.
Background: This one is a JPC puzzle. I saw it for the first time in 12th JPC (2003). I made it for first time in OAPC 6, for Innovative Part of 18th WPC. Then Vladimir made it for BPC 2009, and last it appeared in JZC 2011. Because of the reasons that I mentioned in previous JPC puzzles, I gave the name “Stardust” during OAPC.