IC 405, IC 410 & IC417

In the constellation of Auriga. One of the finest scenes our sky lets us admire in photographs. In this image we can see IC 405, a nebula best appreciated in photographs, lying 1,630 light-years away and illuminated by a variable star, AE Aurigae, probably one of the “runaway” stars born in the Orion Nebula region and since scattered across the Milky Way: this star ionises the nebula's gas, giving it its red colour. The faint blue patches, barely visible in the image near the star, are reflections of its blue light off some dark dust. Lower down and towards the centre we find IC 410, also an emission nebula, though here the gas is ionised by an open star cluster, NGC 1893: it is also called the Tadpole Nebula because of two filaments where major star-formation processes are under way, resembling tadpoles. It lies 19,640 light-years away. The third nebula, designated IC 417, is also called the Spider Nebula: its characteristic red colour, caused by ionised gas, comes here from the open cluster Stock 8. It lies 7,500 light-years away. From these distances, it is clear that IC 410 is by far the largest of the three nebular regions, lying more than ten times farther away than IC 405, even though in the photo, for obvious perspective reasons, they appear on the same plane.