Helios orrery and star dome cochranes of oxford 0142 this helios orrery and star dome model from cochrane s can be set up as either a basic orrery or an orrery with a star dome look through the dome to see the stars visible from earth for your latitude and the time of year see how the stars and constellations have fixed locations in space and how the planets orbit the sun the dome shows all the major stars and constellations around the ecliptic and over the northern hemisphere co