Deirdre,
we used to have a sheet of dots that children could use to make their own constellations.
Similar to it are these set of the 3 night sky pictures, with 3 constellations to find from Project Astro – Constellation Detective.
I have these printed A3 size, laminated, and I tape them to the bottom of the table so that children can lie on their backs and look up at the “sky” to find the constellation.