IC417 and NGC1931 The Spider and the Fly IC417 and NGC1931, the Spider and The Fly Taken on December 9th and 10th 2016 from my Creedmoor site. The Fly (NGC1931) and the Spider (IC417) are emission nebula composed of young star clusters in the constellation Auriga, the Charioteer. The bicolor image was taken through a 7nm Hydrogen Alpha filter and an 8.5nm OIII filter.