The Veil Nebula is a complex and visually striking remnant of a supernova explosion, which has left behind a glowing cloud comprised of heated and ionized gas and dust. Here are some details about its composition and characteristics:

1. Material Composition:
   - The primary constituents of the Veil Nebula include oxygen, sulfur, and hydrogen, as revealed through emission analysis.

2. Physical Features:
   - The nebula is characterized by its delicate filaments of shocked, glowing gas, which are especially noticeable along its western part. These filaments are remnants from the catastrophic explosion that led to its formation.
   - The colors observed within the nebula are not just a visual spectacle but also a representation of its history and evolution. Specifically, the nebula's filaments and colors reveal much about its past and ongoing cosmic interactions.

3. Size and Structure:
   - The Veil Nebula is expansive, spanning about 110 light-years across within the constellation of Cygnus. In visual terms, its entire span corresponds to about six full Moons, as captured in certain images.

4. Origin:
   - The Veil Nebula is a tangible testament to the violent death of a massive star, more specifically, a supergiant star that was 20 times more massive than the Sun. This star underwent a monumental collapse, which then rebounded in a spectacular supernova explosion, leaving behind the ever-expanding glowing remnant known as the Veil Nebula.

5. Observation:
   - It's mentioned that even a small telescope can reveal the wreath of thermonuclear wrath that now forms the Veil Nebula, showcasing the powerful forces at play even thousands of years post the initial supernova event.

Certainly, here are the sources referenced in the information provided:

1. Composition Wikiwand - [Composition of the Veil Nebula](https://www.wikiwand.com/en/Veil_Nebula).
2. Physical Features and Size:
   - NASA - [Veil Nebula: Wisps of an Exploded Star](https://www.nasa.gov/feature/goddard/hubble-revisits-the-veil-nebula).
   - European Space Agency - [Veil Nebula](https://www.esa.int/ESA_Multimedia/Images/2015/09/Veil_Nebula).
   - Science Mission Directorate - [The Veil Nebula](https://science.nasa.gov/veil-nebula).
3. Origin and Observation: Sky & Telescope - [Explore the Veil Nebula](https://skyandtelescope.org/astronomy-resources/exploring-the-veil-nebula/).