Click here for a higher-resolution image
More than a little reminiscent of the Veil Nebula, this is the Pencil Nebula in the constellation Vela, part of the giant Vela Supernova Remmant, leftovers from the explosion of a star about 11,000 years ago. At its brightest this supernova shone at about magnitude -10 and was probably easily visible during the daytime. This image is about a degree wide but the whole Vela Supernova fills about a 10x10-degree area of the sky, so this is just a very small part of it. The "Pencil" name comes from its appearance in a small telescope - just the brightest diagonal line at the upper right is visible, looking like a pencil.
This is a narrowband image in H-alpha and O-III, just 2 hours of total exposure (one hour each of H and O) though a fast 20-inch f/3.8 astrograph.