Veil Nebula with WFPC2 insets
This image shows the east end of the Veil Nebula structure, with the two nebulae NGC6992 (top half) and NGC6995 (bottom half). The highlighted portions are images taken with the Wide Field and Planetary Camera 2 (WFPC2) on board the NASA/ESA Hubble Space Telescope (see related images).
The colour in the WFPC2 image is produced by composite of three different images taken at three different wavelengths using narrow filters centred at 502 nm ([O III]), 656 nm (Hα) and 673 nm ([S II]). The different colours indicate emission from the different kinds of atoms excited by the shock: blue shows oxygen, green shows sulphur, and red shows hydrogen.